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1. 05:29 AM - Re: Battery Solenoid (Relay) (David J. Spencer)
2. 05:44 AM - Re: Battery Solenoid (Relay) (David J. Spencer)
3. 07:31 AM - Re: Battery Solenoid (Relay) (Martini Luc J.R.)
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| Subject: | Re: Battery Solenoid (Relay) |
--> Avionics-List message posted by: "David J. Spencer" <djs@54Transmission.com>
Luc...
You are right about the Triax and terminating it at the BNC... and all this
time I thought it was just my technique or lack of it.
David
----- Original Message -----
From: "Martini Luc J.R." <martini@foxinternet.net>
Subject: Re: Avionics-List: Battery Solenoid (Relay)
> --> Avionics-List message posted by: "Martini Luc J.R."
<martini@foxinternet.net>
>
> Hi again
> I forget to mention something about what you said you used for Coax.
Triax
> is of course a Double Shielded form of Coax, and has the proper 50 Ohm
> impedance just like RG-58 (which also comes in a doble shielded variety).
> However, it has an additional insulation layer between the first and
second
> shield. Obviously, that makes the coax larger in diameter and heavier.
> The cable was actually designed for use on Cable TV systems. By putting
an
> insulator between the shields, they not only kept the better noise
immunity
> that double shielding provided, but more importantly, could use the
shields
> as CONDUCTORS the send power to the INLINE AMPS that the cables systems
need
> to install every 1/2 mile or so to compensate for line losses i.e, one
> shield carried a +28VDC and the other was the Power as well as Signal
> Ground.. cute eh?
>
> The problem in airplanes with TRIAX, is that they are a BITCH to terminate
> at coaxial connectors properly. The greatest problem is because they used
> plastic that melt rather readily at soldering iron temperatures, while the
> better forms of RG-58 used nylon center conductors. And, stripping that
> 2nd layer of plastic so that you can join the braids before jamming them
> into a connector can get REALLY MESSY and at the very least result in one
> hell of a lot of serious cussing.
>
> Luc
> ----- Original Message -----
> From: "David J. Spencer" <djs@54Transmission.com>
> To: <avionics-list@matronics.com>
> Subject: Re: Avionics-List: Battery Solenoid (Relay)
>
>
> > --> Avionics-List message posted by: "David J. Spencer"
> <djs@54Transmission.com>
> >
> > Wow... what a wealth of information... You will never know how much
this
> is
> > helping and I really appreciate your input.
> >
> > First of all this is a single engine plane (1967 Beech Musketeer, 200 hp
> > Lycoming with fuel injection, A23-24 or Super III), so I only have one
> > alternator. Now to the cycling which I mentioned. The VR was a contact
> > type which I replaced with a Zeftronic unit. The cycling continued. I
> then
> > replaced the OV regulator with the matched Zeftronic solid state affair
> and
> > the cycling has stopped. I thought it might be one or the other as
> nothing
> > except the alternator and intercom were running when I last got fed up
> with
> > the noise.
> >
> > Turn off the alternator and the noise went away. It just made sense and
> the
> > VR & OV were both original equipment and 36+ years old.
> >
> > Thank you... You are correct for correcting me about resistance with or
> > without inline devices... I just wasn't thinking when I said there is no
> > difference as I always try to simplify the circuit to it's barest
> essentials
> > and then load on devices until I find a problem. Just my untrained
> > methodology.
> >
> > I will run the amperage test when I get some new battery cable
installed.
> I
> > bought #4 as it met the continuous usage requirements as per the chart
on
> > page 1-10 of Robert G. Horan's "Avionics Installation Handbook"...
> HOWEVER,
> > the plane came with #0 wire and I am going to replace it with #0 wire.
> The
> > run from the battery to the starter solenoid is about 12 feet (12 volt
> > system) and then another 5 feet to the starter. The alternator is a 40
> amp
> > unit, but my guess is that the amperage on engine start may be high
enough
> > to warrant the heavier cable. Anyway what the hell it's just money and
it
> > "might" prevent something I don't understand is going on... safe is
better
> > than crispy.
> >
> > Now to the audio panel. I have a Terra TMA 230 with a marker beacon and
> two
> > Terra TXN-960 NavComs with glide slopes and ILS which I call a radio
> stack.
> > I also have a KLN-88, cooling fan, King KT-76 transponder, Sigtronics
> > SPA-400 intercom and Collins RCR-650/IND 650 ADF. The audio panel has
> three
> > audio grounds (connected) and one chassis ground.
> >
> > AND THANK YOU VERY MUCH -- YOU JUST JOGGED MY MEMORY-- THE GROUNDS FOR
> THE
> > ADF, TRANSPONDER & COOLING FAN ARE NOT ON THE CENTERPOINT SYSTEM. I
also
> > have not put a ground on the radio trays themselves... I think I should.
> >
> > Also, my centerpoint system is a terminal block where all the posts are
> > connected to the same frame point as the ground. This allowed me to
> create
> > a neat little area where all the grounds (except the ones I just
> mentioned)
> > are located. The intercom requires insulating all the headset jacks
(with
> > isolation washers) and using the centerpoint ground.
> >
> > Now to the Cone of Static... below is a diagram of the airport in
> > relationship to some 1600' AGL radio, TV & Microwave transmission towers
> > which are South of the field about 5 miles. The airport is directly
> between
> > the towers and Downtown Dallas Texas. Is it possible that the towers
> could
> > be transmitting a directional signal toward downtown?
> >
> >
> > ++++
> >
> > +++++ Radio Transmission towers (~15 @ 1600' AGL)
> >
> > +++++
> >
> >
> about
> > five miles to towers
> >
> >
> > |
> > |
> > | Runway
> (17/35)
> > |
> > |
> >
> >
> > about three miles
> >
> > DOWNTOWN DALLAS TEXAS
> >
> > As for large metallic structures...there are two hangars built by Howard
> > Hughes for something really big right on the 17/35 runway. Other than
> that
> > there is an FBI/U.S. Customs helicopter hangar (which tends to be rather
a
> > secretive place) on the South end of the field and a medium sized strip
> mall
> > just across a highway to the South. There is also a six story Wells
Fargo
> > Bank down by the FBI.
> >
> > There is a National Guard Armory on the West side of the field which, I
> > believe has some radio antennae sticking up in the wooded area adjacent
to
> > it... I'll check on the way home. My wife (she's a pilot also) says
she
> > thinks the bank tower has dish antennae on it... either the bank or the
> FBI.
> > That's her side of the plane so I never look out there, because I don't
> want
> > to see what she's going to hit, and will check on it on way home.
> >
> > The antennas are well grounded, but are on the aft slope of the top of
the
> > fuselage (fuselage much like a V-35 Bonanza). After putting in the ADF
> > which required triaxial cable I changed EVERYTHING to triaxial as it
just
> > seemed the logical thing to do.
> >
> > They are too close together (about 2 feet apart), but are about 5 feet
aft
> > of the Loran antenna. The transponder is under the foward fuselage
(blade
> > type) and the ADF & marker beacon are on the bottom aft fuselage. The
> > aftmost comm antenna is very close to the vertical stabilizer which has
an
> > ABS plastic shroud on the leading edge to affect airflow. I never
thought
> > much about the static from plastic as all I've read indicates that our
> plane
> > is too slow... we cruise at ~145-150 mph with take-off and climb at
90-100
> > mph. Should I install some static wicks?
> >
> > We only get this static garbage at this airport... no where else we have
> > flown has given us any problems and we have been into some strange
places
> > like the Arizona & New Mexico desert and along the U.S./ Mexico border.
> >
> > You will never know how much you are helping... I tend to be a rather
> > tenacious person and want very much to understand as much as possible
> about
> > what is going on and how to eliminate it... if possible.
> >
> > David
> >
> >
> > ----- Original Message -----
> > From: "Martini Luc J.R." <martini@foxinternet.net>
> > To: <avionics-list@matronics.com>
> > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> >
> >
> > > --> Avionics-List message posted by: "Martini Luc J.R."
> > <martini@foxinternet.net>
> > >
> > > Hello again
> > >
> > > There can be a very considerable difference in resitance readings of a
> VOM
> > > for forward v. reverse polarity if you have an "Active Device" in the
> > > circuit... i.e. a Diode, or a Transistor. Looking from the battery,
> you
> > > could be looking at several of these, (diodes or transistors) which
are
> > > used for noise suppression, voltage spike protection, even
internally
> in
> > a
> > > voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not isolated
by
> a
> > > circuit breaker.
> > >
> > > If there is No change as you indicated, that simply verifies that you
> > likely
> > > DO NOT have an Active Device in the Battery Bus Circuit, since Active
> > > Devices are very NON LINEAR, i.e., the reading you get on a VOM is
> > typically
> > > MUCH higher in one polarity than the other.
> > >
> > > If your VOM has a 1 amp direct reading capability, the way to proceed
> is
> > to
> > > disconnected the + lead from the battery. Set your VOM to DC CURRENT
> > > (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in
SERIES
> > > with the battery, i.e., VOM - lead to battery cable (where the LOAD
is),
> > and
> > > + lead to the battery + lead (Current Source).
> > >
> > > The reading you will get will be in either MILLIAMPS (ma) or AMPS
(A)..
> > > depending on your meter...if the scale is calibrated in (ma), move
the
> > > decimal place to the right 3 spaces (X 1000) for (amps)
> > >
> > > If you are using your fully charged aircraft battery,. you should get
> > 1.09
> > > Amps showing on the meter.:
> > >
> > > 12 VDC/11 OHMS = 1.09 AMPS.
> > >
> > > Note that if you use external power the voltage might be higher, up
to
> 14
> > > volts.. that might damage your VOM since that is 1.3 Amps.
> > >
> > > You may have done this already according to your note, but you read
the
> > > VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each meter
> is
> > > different, I have no way of knowing what the .245 you referred to
really
> > is.
> > >
> > > The nice thing about using a CURRENT METER is that you can leave it
> hooked
> > > up and go disconnect various things that power goes to, i.e voltage
> > > regulators, bulkhead connectors, circuit breakers, etc. and with a
quick
> > > check see if the current dropped to ZERO.... BINGO... your problem is
in
> > > THAT CIRCUIT.
> > >
> > > As to your question about Avionics Signal and Power Grounds. NO, they
> > MUST
> > > be connected together at ONE and ONLY one place for noise immunity...
> > also
> > > helps with lighning protection. Signal ground is not the same as
AUDIO
> > > ground.
> > >
> > > That is not to say that Avionics Shops do things right... as you have
> > found
> > > out.
> > >
> > > There is one other thing I should tell you about. Audio Panels are an
> > even
> > > MORE complicated item. In Audio Panels, they may have as many as 2
MORE
> > > types of Grounds. King (KMA-24) is famous for this. You have to
Isolate
> > the
> > > AUDIO GROUNDS as well. and may have to isolate the Pilot and Co-pilot
> > audio
> > > from ANY OTHER audio ground, as well as isolation from CHASIS GROUND.
> > > These suckers can be real bears, and the source of Noise PICKUP (from
> > > external sources such as motors, sparks (like bad shielding on spark
> plug
> > > wires) and even external to the aircraft.. industrial sources.
> > >
> > > The Noise Zone you mention is intriguing. There are two ways of
looking
> > at
> > > the problem.. 1) that there exists a NOISE SOURCE in that area, or 2),
> > that
> > > there exists a SHIELD from radiation.
> > >
> > > I believe the first is what everybody has been focused on. However,
the
> > > second is just as likely if not more so. For example, if there is a
> > > significant magnetic disturbance in the area, or a very large metalic
> > > structure in the area, or a hill with a lot of iron content.. etc.
etc.
> > > these can shield the background RF Noise Level The Automatic Gain
> > Control
> > > (AGC) circuits in you radios, and/or audio panel, would compensate by
> > > INCREASING the GAIN... that would result in audio STATIC...exactly
like
> > what
> > > you get when listening to your AM radio in the car when you drive
> through
> > a
> > > tunnel.
> > >
> > > I got the point you made that you had EVERYTHING disconnected except
> the
> > > Battery and the Avionics DC bus and of course the radios that power
> them..
> > > One thing you should also do, is turn of your Transponder. Also, if
the
> > > Antenna Coax for the Transponder and the DME (if you have one) are
run
> > > parallel with other wiring bundles, that can be a source of severe
> static.
> > > I always use Double Shielded Coax for these devices... some Av Shops
do
> > > not... and if I have to cross a wire bundle, I do it at as close to 90
> > > degrees as I can.(the Electric and Magnetic Fields no not couple to
the
> > > other cable when; you do that) Obviously it pays to keep these Coax
> > leads
> > > as short as possible (but must generally be no shorter than 3 feet
(1/2
> > wave
> > > length).
> > >
> > > Another general practice to follow is good GROUND PLANES for the
> antennas.
> > > What that means generally, is as much flat metal around the antenna as
> > your
> > > airplane and avionics can afford; keep radiating elements like DME
and
> > > Transponder seperated by 6' from each other.. as well as from very low
> > > signal sources like LORAN, GPS...Keep the Comm antenna away from those
> as
> > > well... and strangely enough, keep these well away and UP-STREAM
> > > (airstream) from non-electrically conductive surfaces such as
> Plexiglass,
> > > Fiberglass etc. (these create static electricity that can couple the
> > > discharge via inonizatiotion of the airstream) Then, have a Good Low
> > ohmic
> > > contact for the antennas. That means cleaning away all paint where
the
> > > antenna mounts, and Alodining the area. and on the INSIDE of the
> > airplane,
> > > make sure that your have a good clean contact in like fashion for the
> > > antenna mounting nuts/bolts.
> > >
> > > I just received another e-mail from you... about the odd charging
habits
> > of
> > > your airplane. Keep in mind, that a fully charged battery is 12 VDC.
> > > However, your voltage regulator puts out between 13.5 and 14.00 volts
> > > depending on the current draw, and the internal setting of you voltage
> > > regulator. You would be surprised at the variation in "Idling Current"
> > from
> > > one Regulator to the next. So, it does NOT surprise me that even
after
> > > starting your engines with a full battery, that they do a little
chargin
> > for
> > > a while. What DOES surprise me is the CYCLING you mentioned. That
was
> > > common in the old days of RELAY type voltage regulagtors, but NOT for
> > Solid
> > > state Alternator Regulators.
> > >
> > > Do you have some sort of switching arangement for left/right engine
> > > alternators?
> > >
> > > Luc
> > >
> > >
> > > ----- Original Message -----
> > > From: "David J. Spencer" <djs@54Transmission.com>
> > > To: <avionics-list@matronics.com>
> > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > >
> > >
> > > > --> Avionics-List message posted by: "David J. Spencer"
> > > <djs@54Transmission.com>
> > > >
> > > > Luc...
> > > >
> > > > The resistance didn't change with a reverse in polarity... it rarely
> > does.
> > > >
> > > > My VOM has a 1 amp capability. When I set it to AC voltage and ran
a
> > > check
> > > > with the +/- cables I got .245 volt flow in either direction.
> > > >
> > > > You raise an interesting point about the two different types of
> > grounds...
> > > > power and audio. Both are separated in the wiring harness, but
> > connected
> > > to
> > > > the same center point ground. Should there be two center point
> grounds?
> > > >
> > > > Everything is very clean as I just rebuilt the wiring harness. I
have
> > had
> > > > it out twice and rechecked for faulty wiring or shielding touching
the
> > > > center wire and it checks out just fine.
> > > >
> > > > With the DC power source hooked directly to the power cable (I come
> off
> > > the
> > > > power bus with one power cable to the audio panel, 2 NavComs,
> > transponder,
> > > > ADF and intercom though another set of breakers) to the radio stack,
> the
> > > > only thing I eliminated was the battery and the associated wiring...
> all
> > > > other noise sources (motors, alternator, gyros, etc.) were always
off.
> > I
> > > > was getting the hum just off the battery power with no other motors,
> > > > solenoids, regulators, gyros or anything turned on even connected.
> > > >
> > > > The + cable was the one with the crimp in it. The negative cable is
> > only
> > > > about 18" long and connected to the frame.
> > > >
> > > > I have not checked the grounding strap from the engine to the
firewall
> > > > within the last two months, but will be checking that also along
with
> > the
> > > > starter cables, ammeter cables (which I found had some "burned
spots"
> on
> > > > them which was hidden from view until you "unbundled" all the
wiring)
> > and
> > > > installing an AmeriKing DC filter and Alternator filter. I've
always
> > > though
> > > >
> > > > Last year I replaced all the antenna cables as I found them to be
> > bundled
> > > > and taped to the + power cable. I also replaced all the comm
antennae
> > > > (fiberglass and cracked) with stainless steel, which helped a lot.
> The
> > > > controlled field I fly out of has a "cone of static" which many
> complain
> > > > about, but the FAA and FCC can't seem to isolate or do anything
about,
> > but
> > > > rather claim it's everybody's radios... when you lift off,
sometimes,
> > the
> > > > static is so bad you have to turn off the radios...
> > > >
> > > > I also replaced the alternator, voltage regulator and OV regulator
> plus
> > > all
> > > > the associated wiring as some Avionics moron had butt spliced the
> field
> > > wire
> > > > "INSIDE" the firewall cannon plug. The butt splice was broken and,
of
> > > > course, the field wire was going to ground. After 3 avionics shops
> > > checked
> > > > my alternator I took it out myself and found 3 diodes were bad...
> > > > AeroElectric found that one more was bad when they replaced my
> > alternator
> > > > with an upgraded version with larger bearings.
> > > >
> > > > Yesterday as I pulled out the + battery power cable, I found all the
> > > lights,
> > > > strobe, electric fuel pump, and fuel sensors taped (relatively new
> > looking
> > > > tape) to the + power cable. Needless to say, during it's 36 year
> > > existence,
> > > > maintenance has always been done in FAA certified shops and done
with
> a
> > > very
> > > > high level of poor quality.
> > > >
> > > > I honestly think this is a wiring problem relative to 36 y/o wire,
but
> I
> > > > won't know until I get all the wiring replaced and according to
Beech
> > > wiring
> > > > diagram specifications.
> > > >
> > > > Thanks for you help and input...
> > > >
> > > > David J. Spencer
> > > > Super3
> > > > djs@54Transmission.com
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: "Martini Luc J.R." <martini@foxinternet.net>
> > > > To: <avionics-list@matronics.com>
> > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > >
> > > >
> > > > > --> Avionics-List message posted by: "Martini Luc J.R."
> > > > <martini@foxinternet.net>
> > > > >
> > > > > What was the reverse polarity reading? I assume since you did
not
> > give
> > > a
> > > > > value for another range on the VOM, that it was a Digitial Type.
> > > > >
> > > > > Do you have a 1 amp Current meter? From the ohmic check, that's
> about
> > > the
> > > > > current you are drawing if this is a DC load. If not, hook a 100
> ohm
> > > > > resistor in series with the + battery Cable and measure the
voltage
> > > drop
> > > > > across the resistor.
> > > > >
> > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic
> contact)
> > > are
> > > > > EVERYTHING.
> > > > >
> > > > > However, there are frequently 2 ground levels, SIGNAL ground and
> POWER
> > > > > ground. Great care must be taken when assembling your avionics
to
> > keep
> > > > > these two seperate, and connect them only at a SINGLE POINT
ground.
> > > > >
> > > > > It is not a bad idea to stick your head under the panel, and clean
> the
> > > > > single point avionics ground to make sure the spade lugs and
washers
> > > are
> > > > > not oxidized (high ohmic contact)
> > > > >
> > > > > It does not surprise me that with EXTERNAL DC power, that you do
> NOT
> > > have
> > > > > radio hum. since your do NOT have a source of noise..
> > > > generator/alternator,
> > > > > motors, etc.
> > > > >
> > > > > You did not mention if it was the + or the - battery lead that had
a
> > > crimp
> > > > > splice in it. If it was in the + lead. other than creating a
> voltage
> > > > > drop... which would be reflected to the voltage regulator, i.e.
the
> > > > > generator/alternator would be putting out more voltage than it
> should
> > > > > because it senses a Battery slightly low voltage condition. If
on
> > the
> > > > > other hand it was on the - side. as far as the radios go, it
would
> be
> > > > like
> > > > > putting a resistance between the - battery terminal and Chasis
> Ground.
> > > > This
> > > > > could conceiveably cause the noise floor to be raised...but not
> likely
> > > if
> > > > > yourGenrator/Alternator grouind is good... By the way... have to
> > > checked
> > > > > that to make sure you have a good & clean grounding strap from the
> > > engine
> > > > to
> > > > > the firewall ??
> > > > >
> > > > > Luc
> > > > >
> > > > >
> > > > > ssage -----
> > > > > From: "David J. Spencer" <djs@54Transmission.com>
> > > > > To: <avionics-list@matronics.com>
> > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > > >
> > > > >
> > > > > > --> Avionics-List message posted by: "David J. Spencer"
> > > > > <djs@54Transmission.com>
> > > > > >
> > > > > > Luc...
> > > > > >
> > > > > > There was approximately 11 ohms between the + & - with the
correct
> > > > > polarity
> > > > > > hook up on the VOM.
> > > > > >
> > > > > > I took out the battery cable yesterday and found a split in the
> > > > insulation
> > > > > > about 3/8" long which had been taped over. The cable itself had
> > been
> > > > > > "crimped" creating a bulge and part of the internal wiring was
> > broken
> > > at
> > > > > > that point.
> > > > > >
> > > > > > As best I could tell this open area was not laying on the skin
but
> ,
> > > > > rather,
> > > > > > pointing away from the skin as the cable lay on the belly of the
> > > plane.
> > > > > >
> > > > > > This is being corrected with new wiring and proper attachments.
> > > > > >
> > > > > > I hooked the radios up to a DC power source i.e. they are
isolated
> > > from
> > > > > > anything (except the antenna)... and the hum went away.
> > > > > >
> > > > > > David J. Spencer
> > > > > > Super3
> > > > > > djs@54Transmission.com
> > > > > >
> > > > > > ----- Original Message -----
> > > > > > From: "Martini Luc J.R." <martini@foxinternet.net>
> > > > > > To: <avionics-list@matronics.com>
> > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > > > >
> > > > > >
> > > > > > > --> Avionics-List message posted by: "Martini Luc J.R."
> > > > > > <martini@foxinternet.net>
> > > > > > >
> > > > > > > What resistance do you read between the battery cable and
> ground.
> > > Be
> > > > > sure
> > > > > > > to take the measurement with the leads swapped as well as
> standard
> > > > > > polarity,
> > > > > > > i.e. red lead to + and black to -.. If you are NOT using a
> > digital
> > > > VOM,
> > > > > > > then also take values in both polarities in more than one
RANGE
> on
> > > the
> > > > > VOM
> > > > > > > (active devices - diodes /transistors - are non-linear.. give
> you
> > a
> > > > good
> > > > > > > clue if the value changes). You may have another noise
> suppression
> > > > diode
> > > > > > > somewhere, and/or an RC type (Band Pass) noise filter , with
> > > possibly
> > > > a
> > > > > > bad
> > > > > > > capacitor in it.
> > > > > > >
> > > > > > > Let me know what you get.
> > > > > > >
> > > > > > > Luc Martini
> > > > > > > ----- Original Message -----
> > > > > > > From: "David J. Spencer" <djs@54Transmission.com>
> > > > > > > To: <avionics-list@matronics.com>
> > > > > > > Subject: Avionics-List: Battery Solenoid (Relay)
> > > > > > >
> > > > > > >
> > > > > > > > --> Avionics-List message posted by: "David J. Spencer"
> > > > > > > <djs@54Transmission.com>
> > > > > > > >
> > > > > > > > Hi all...
> > > > > > > >
> > > > > > > > Has anyone ever replaced the battery relay on their Beech
> A23-24
> > > > Super
> > > > > > > III?
> > > > > > > >
> > > > > > > > My relay seems to work fine, but is 36 y/o and uses a
Kipvolt
> > > > Voltage
> > > > > > > > suppressor (diode) to eliminate voltage spikes flushing
> through
> > > the
> > > > > > > system.
> > > > > > > >
> > > > > > > > I am replacing the battery, ground and starter cables with
> new
> > > > cable
> > > > > > (AC
> > > > > > > > grade #0 wire for the 40 amp system) and am wondering if
> anyone
> > > has
> > > > > put
> > > > > > > in
> > > > > > > > a
> > > > > > > > new Aircraft grade battery relay from an aircraft supply
> > (Spruce)
> > > > > > source
> > > > > > > > battery relay in place of ours.
> > > > > > > >
> > > > > > > > I can currently remove the battery, diode and battery rely
> and
> > > get
> > > > > > > current
> > > > > > > > continuity (VOM) through the system from the positive
cable
> to
> > > the
> > > > > > > > negative cable or any
> > > > > > > > ground... everything is off... i.e switches, breaker etc.
> This
> > > is
> > > > > what
> > > > > > > > some
> > > > > > > > people think is causing a "hum" in the radios. The "hum"
is
> > > > present
> > > > > > with
> > > > > > > > the engine off and running the radios off a fully charged
> > > battery.
> > > > .
> > > > > > > > Additionally, using the AC voltage test setup on the VOM I
> can
> > > > detect
> > > > > > > > current flow between the positive cable and ground... any
> > ground.
> > > > > > > >
> > > > > > > >
> > > > > > > > I'm using certer point grounding, but all the avionics
manual
> > > > > articles
> > > > > > > > point
> > > > > > > > to RMI induced noise through the hull by poor shielding on
> the
> > DC
> > > > > power
> > > > > > > > lines.
> > > > > > > >
> > > > > > > > Beech doesn't seem to have these parts anymore.
> > > > > > > >
> > > > > > > > All comments welcomed...
> > > > > > > >
> > > > > > > > David J. Spencer
> > > > > > > > Super3
> > > > > > > > djs@54Transmission.com
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>
Message 2
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| Subject: | Re: Battery Solenoid (Relay) |
--> Avionics-List message posted by: "David J. Spencer" <djs@54Transmission.com>
Luc...
As far as magnetic deviation, I'm not aware of anything on the maps (and
I've flown here for 30+ years) which indicates anything abnormal.
Are you saying that static wicks and control surface bonding straps will
increase the effective range of the radios? I don't have any problem with
the cost of the wicks if they have advantages... I was just under the
impression that unless you used a mach number as airspeed they didn't
matter... wrong again.
Yes other people have bitched about the static in the area... one instructor
says it is really irritating.
I went by the airport last night and found that not only do we have the TV,
radio, microwave towers 5 miles south, we have a AM/FM radio station right
on the field. That's the stuff on my wife's side of the plane that I never
look at. They have got 4 dish antennae, and some sort of vertical strip
antenna (about 4-6 8' vertical strips per antenna and about three of
these) on a 6 story building just off the airport property.
In addition there is a fire station with it's radio system just off the
perimeter and a cell phone tower about a 1/4 mile off the property.
I don't know of any Ham operators in the area, but could probably find some.
Again thanks for the help...
David
----- Original Message -----
From: "Martini Luc J.R." <martini@foxinternet.net>
Subject: Re: Avionics-List: Battery Solenoid (Relay)
> --> Avionics-List message posted by: "Martini Luc J.R."
<martini@foxinternet.net>
>
> Glad to help out.
>
> I forgot to ask if there is a significant Magnetic Deviation in that area
> (what do they show on the maps?).. that would indicate an iron
concentration
> in the ground that could be acting as an RF shield. The effective range
of
> signals like VOR would also be decreased in such an area.
>
> As for Static wicks.. they never hurt, but are not all that cheap. Static
> discharge is more a function of humidity (altitude) than airspeed. There
> are 2
> advantages to Static wicks in addition to possibly reducing radio noise !)
> is reduces galvanic corrosion..2) if you get hit by lightning, the tuffs
> disappear instead of a piece of your flight control surfaces.
> A lot of people don't realize that a plasma is not just a current, but
> actually moves mater. The example I like to point out are the points in
an
> old distributor... No doubt you have noticed, that one side it builds a
> mountain, and the other side a pit. The mountain and the pit are always
on
> the same side of the points. Current flows from - to +. when you open
the
> points a plasma arc forms. The flow of electrons (which are pretty light
> but there are a lot of them and traveling at near the speed of
> light. However, at the moment you open the circuit, the total energy in
the
> system must be equal, and you just stopped E=MC squared going that away
> (toward the possitive terminal) instantaneously, For things to equal out,
> metal (mass) must flow in the opposite direction to equalize energy state
> equation. Electrons are light, so it does not take many atoms of
> metal going much slower in the opposite direction for things to equal out,
> quenching the plasma. The result however is that the metal builds up over
> time on the - side of the points.. and that metal obviously comes from the
> + side.
>
> So, if your airplane is hit with lightning, the tuffs will vaporize... In
> military airplanes, they also provide bonding straps between the fuselage
> and the flight control surfaces, so that no arcing occurs in the bearing/
> bolts/pins that hold them on.
>
> For the radios, you might be surprised how much you gain is Effective
Range
> for your receivers.. you find you pick up VOR stations for example quite
a
> few miles further out than before you spent your money and time on
reducing
> noise sources.
>
> I take it that other people have bitched about the noise problem in your
> local area.
>
> With the advent of Cellphones, the general noise level have increased
> dramatically. That is because cellphones are a SWITCHED System. When
ever
> you switch something on and off , you create noise. Take again for
example,
> the old car distributor with points. If you create a PLASMA, you are
> radiating Radio Frequencies (Usually AM) , and as everyone knows, you
> splatter AM noise
> content all over the dial . If you SWITCH an RF signal on and off, the
> amount of Noise content you generate is directly proportional to the Rise
> and Fall time of the pulse. The faster the switch things on and off, the
> worse it gets. A Zero Rise and Fall time,,, which is of course
impossible,
> would splatter equal amplitude from DC to Infinity. (and such noise could
> also be FM -harmonic content) So, in short,
> cellphones suck for radio... They have been the bane of Broadcast TV for
> example..
>
> And, as you might have expected, if the Ambient Noise Level goes UP, your
> radio AGC compensates by turning the Signal Gain DOWN to compensate... Not
> nice!
>
> Do you by chance know any Ham Radio Operators in your area??? Those guys
> would be your best bet for finding the Noise SOURCE in the neighborhood.
> There is an instrument called a Field Strength Meter, which is nothing
more
> than a Directional Antenna hooked to a TUNED Circuit, hooked up to an AM
> detector (diode) and that in turn to a sensitive meter movement. In
short,
> a radio of sorts. They can go around and see where the strongest signals
> are coming from, and use their ham gear to see if the noise is strictly AM
> or possibly FM as well, and how much bandwidth is affected. THEN you can
go
> to the guys causing the problem and threaten them with legal action if
they
> don't clean up their act and/or go to the FAA and FCC with evidence in
hand
> and bitch.
>
> Luc
>
>
> ----- Original Message -----
> From: "David J. Spencer" <djs@54Transmission.com>
> To: <avionics-list@matronics.com>
> Subject: Re: Avionics-List: Battery Solenoid (Relay)
>
>
> > --> Avionics-List message posted by: "David J. Spencer"
> <djs@54Transmission.com>
> >
> > Wow... what a wealth of information... You will never know how much
this
> is
> > helping and I really appreciate your input.
> >
> > First of all this is a single engine plane (1967 Beech Musketeer, 200 hp
> > Lycoming with fuel injection, A23-24 or Super III), so I only have one
> > alternator. Now to the cycling which I mentioned. The VR was a contact
> > type which I replaced with a Zeftronic unit. The cycling continued. I
> then
> > replaced the OV regulator with the matched Zeftronic solid state affair
> and
> > the cycling has stopped. I thought it might be one or the other as
> nothing
> > except the alternator and intercom were running when I last got fed up
> with
> > the noise.
> >
> > Turn off the alternator and the noise went away. It just made sense and
> the
> > VR & OV were both original equipment and 36+ years old.
> >
> > Thank you... You are correct for correcting me about resistance with or
> > without inline devices... I just wasn't thinking when I said there is no
> > difference as I always try to simplify the circuit to it's barest
> essentials
> > and then load on devices until I find a problem. Just my untrained
> > methodology.
> >
> > I will run the amperage test when I get some new battery cable
installed.
> I
> > bought #4 as it met the continuous usage requirements as per the chart
on
> > page 1-10 of Robert G. Horan's "Avionics Installation Handbook"...
> HOWEVER,
> > the plane came with #0 wire and I am going to replace it with #0 wire.
> The
> > run from the battery to the starter solenoid is about 12 feet (12 volt
> > system) and then another 5 feet to the starter. The alternator is a 40
> amp
> > unit, but my guess is that the amperage on engine start may be high
enough
> > to warrant the heavier cable. Anyway what the hell it's just money and
it
> > "might" prevent something I don't understand is going on... safe is
better
> > than crispy.
> >
> > Now to the audio panel. I have a Terra TMA 230 with a marker beacon and
> two
> > Terra TXN-960 NavComs with glide slopes and ILS which I call a radio
> stack.
> > I also have a KLN-88, cooling fan, King KT-76 transponder, Sigtronics
> > SPA-400 intercom and Collins RCR-650/IND 650 ADF. The audio panel has
> three
> > audio grounds (connected) and one chassis ground.
> >
> > AND THANK YOU VERY MUCH -- YOU JUST JOGGED MY MEMORY-- THE GROUNDS FOR
> THE
> > ADF, TRANSPONDER & COOLING FAN ARE NOT ON THE CENTERPOINT SYSTEM. I
also
> > have not put a ground on the radio trays themselves... I think I should.
> >
> > Also, my centerpoint system is a terminal block where all the posts are
> > connected to the same frame point as the ground. This allowed me to
> create
> > a neat little area where all the grounds (except the ones I just
> mentioned)
> > are located. The intercom requires insulating all the headset jacks
(with
> > isolation washers) and using the centerpoint ground.
> >
> > Now to the Cone of Static... below is a diagram of the airport in
> > relationship to some 1600' AGL radio, TV & Microwave transmission towers
> > which are South of the field about 5 miles. The airport is directly
> between
> > the towers and Downtown Dallas Texas. Is it possible that the towers
> could
> > be transmitting a directional signal toward downtown?
> >
> >
> > ++++
> >
> > +++++ Radio Transmission towers (~15 @ 1600' AGL)
> >
> > +++++
> >
> >
> about
> > five miles to towers
> >
> >
> > |
> > |
> > | Runway
> (17/35)
> > |
> > |
> >
> >
> > about three miles
> >
> > DOWNTOWN DALLAS TEXAS
> >
> > As for large metallic structures...there are two hangars built by Howard
> > Hughes for something really big right on the 17/35 runway. Other than
> that
> > there is an FBI/U.S. Customs helicopter hangar (which tends to be rather
a
> > secretive place) on the South end of the field and a medium sized strip
> mall
> > just across a highway to the South. There is also a six story Wells
Fargo
> > Bank down by the FBI.
> >
> > There is a National Guard Armory on the West side of the field which, I
> > believe has some radio antennae sticking up in the wooded area adjacent
to
> > it... I'll check on the way home. My wife (she's a pilot also) says
she
> > thinks the bank tower has dish antennae on it... either the bank or the
> FBI.
> > That's her side of the plane so I never look out there, because I don't
> want
> > to see what she's going to hit, and will check on it on way home.
> >
> > The antennas are well grounded, but are on the aft slope of the top of
the
> > fuselage (fuselage much like a V-35 Bonanza). After putting in the ADF
> > which required triaxial cable I changed EVERYTHING to triaxial as it
just
> > seemed the logical thing to do.
> >
> > They are too close together (about 2 feet apart), but are about 5 feet
aft
> > of the Loran antenna. The transponder is under the foward fuselage
(blade
> > type) and the ADF & marker beacon are on the bottom aft fuselage. The
> > aftmost comm antenna is very close to the vertical stabilizer which has
an
> > ABS plastic shroud on the leading edge to affect airflow. I never
thought
> > much about the static from plastic as all I've read indicates that our
> plane
> > is too slow... we cruise at ~145-150 mph with take-off and climb at
90-100
> > mph. Should I install some static wicks?
> >
> > We only get this static garbage at this airport... no where else we have
> > flown has given us any problems and we have been into some strange
places
> > like the Arizona & New Mexico desert and along the U.S./ Mexico border.
> >
> > You will never know how much you are helping... I tend to be a rather
> > tenacious person and want very much to understand as much as possible
> about
> > what is going on and how to eliminate it... if possible.
> >
> > David
> >
> >
> > ----- Original Message -----
> > From: "Martini Luc J.R." <martini@foxinternet.net>
> > To: <avionics-list@matronics.com>
> > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> >
> >
> > > --> Avionics-List message posted by: "Martini Luc J.R."
> > <martini@foxinternet.net>
> > >
> > > Hello again
> > >
> > > There can be a very considerable difference in resitance readings of a
> VOM
> > > for forward v. reverse polarity if you have an "Active Device" in the
> > > circuit... i.e. a Diode, or a Transistor. Looking from the battery,
> you
> > > could be looking at several of these, (diodes or transistors) which
are
> > > used for noise suppression, voltage spike protection, even
internally
> in
> > a
> > > voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not isolated
by
> a
> > > circuit breaker.
> > >
> > > If there is No change as you indicated, that simply verifies that you
> > likely
> > > DO NOT have an Active Device in the Battery Bus Circuit, since Active
> > > Devices are very NON LINEAR, i.e., the reading you get on a VOM is
> > typically
> > > MUCH higher in one polarity than the other.
> > >
> > > If your VOM has a 1 amp direct reading capability, the way to proceed
> is
> > to
> > > disconnected the + lead from the battery. Set your VOM to DC CURRENT
> > > (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in
SERIES
> > > with the battery, i.e., VOM - lead to battery cable (where the LOAD
is),
> > and
> > > + lead to the battery + lead (Current Source).
> > >
> > > The reading you will get will be in either MILLIAMPS (ma) or AMPS
(A)..
> > > depending on your meter...if the scale is calibrated in (ma), move
the
> > > decimal place to the right 3 spaces (X 1000) for (amps)
> > >
> > > If you are using your fully charged aircraft battery,. you should get
> > 1.09
> > > Amps showing on the meter.:
> > >
> > > 12 VDC/11 OHMS = 1.09 AMPS.
> > >
> > > Note that if you use external power the voltage might be higher, up
to
> 14
> > > volts.. that might damage your VOM since that is 1.3 Amps.
> > >
> > > You may have done this already according to your note, but you read
the
> > > VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each meter
> is
> > > different, I have no way of knowing what the .245 you referred to
really
> > is.
> > >
> > > The nice thing about using a CURRENT METER is that you can leave it
> hooked
> > > up and go disconnect various things that power goes to, i.e voltage
> > > regulators, bulkhead connectors, circuit breakers, etc. and with a
quick
> > > check see if the current dropped to ZERO.... BINGO... your problem is
in
> > > THAT CIRCUIT.
> > >
> > > As to your question about Avionics Signal and Power Grounds. NO, they
> > MUST
> > > be connected together at ONE and ONLY one place for noise immunity...
> > also
> > > helps with lighning protection. Signal ground is not the same as
AUDIO
> > > ground.
> > >
> > > That is not to say that Avionics Shops do things right... as you have
> > found
> > > out.
> > >
> > > There is one other thing I should tell you about. Audio Panels are an
> > even
> > > MORE complicated item. In Audio Panels, they may have as many as 2
MORE
> > > types of Grounds. King (KMA-24) is famous for this. You have to
Isolate
> > the
> > > AUDIO GROUNDS as well. and may have to isolate the Pilot and Co-pilot
> > audio
> > > from ANY OTHER audio ground, as well as isolation from CHASIS GROUND.
> > > These suckers can be real bears, and the source of Noise PICKUP (from
> > > external sources such as motors, sparks (like bad shielding on spark
> plug
> > > wires) and even external to the aircraft.. industrial sources.
> > >
> > > The Noise Zone you mention is intriguing. There are two ways of
looking
> > at
> > > the problem.. 1) that there exists a NOISE SOURCE in that area, or 2),
> > that
> > > there exists a SHIELD from radiation.
> > >
> > > I believe the first is what everybody has been focused on. However,
the
> > > second is just as likely if not more so. For example, if there is a
> > > significant magnetic disturbance in the area, or a very large metalic
> > > structure in the area, or a hill with a lot of iron content.. etc.
etc.
> > > these can shield the background RF Noise Level The Automatic Gain
> > Control
> > > (AGC) circuits in you radios, and/or audio panel, would compensate by
> > > INCREASING the GAIN... that would result in audio STATIC...exactly
like
> > what
> > > you get when listening to your AM radio in the car when you drive
> through
> > a
> > > tunnel.
> > >
> > > I got the point you made that you had EVERYTHING disconnected except
> the
> > > Battery and the Avionics DC bus and of course the radios that power
> them..
> > > One thing you should also do, is turn of your Transponder. Also, if
the
> > > Antenna Coax for the Transponder and the DME (if you have one) are
run
> > > parallel with other wiring bundles, that can be a source of severe
> static.
> > > I always use Double Shielded Coax for these devices... some Av Shops
do
> > > not... and if I have to cross a wire bundle, I do it at as close to 90
> > > degrees as I can.(the Electric and Magnetic Fields no not couple to
the
> > > other cable when; you do that) Obviously it pays to keep these Coax
> > leads
> > > as short as possible (but must generally be no shorter than 3 feet
(1/2
> > wave
> > > length).
> > >
> > > Another general practice to follow is good GROUND PLANES for the
> antennas.
> > > What that means generally, is as much flat metal around the antenna as
> > your
> > > airplane and avionics can afford; keep radiating elements like DME
and
> > > Transponder seperated by 6' from each other.. as well as from very low
> > > signal sources like LORAN, GPS...Keep the Comm antenna away from those
> as
> > > well... and strangely enough, keep these well away and UP-STREAM
> > > (airstream) from non-electrically conductive surfaces such as
> Plexiglass,
> > > Fiberglass etc. (these create static electricity that can couple the
> > > discharge via inonizatiotion of the airstream) Then, have a Good Low
> > ohmic
> > > contact for the antennas. That means cleaning away all paint where
the
> > > antenna mounts, and Alodining the area. and on the INSIDE of the
> > airplane,
> > > make sure that your have a good clean contact in like fashion for the
> > > antenna mounting nuts/bolts.
> > >
> > > I just received another e-mail from you... about the odd charging
habits
> > of
> > > your airplane. Keep in mind, that a fully charged battery is 12 VDC.
> > > However, your voltage regulator puts out between 13.5 and 14.00 volts
> > > depending on the current draw, and the internal setting of you voltage
> > > regulator. You would be surprised at the variation in "Idling Current"
> > from
> > > one Regulator to the next. So, it does NOT surprise me that even
after
> > > starting your engines with a full battery, that they do a little
chargin
> > for
> > > a while. What DOES surprise me is the CYCLING you mentioned. That
was
> > > common in the old days of RELAY type voltage regulagtors, but NOT for
> > Solid
> > > state Alternator Regulators.
> > >
> > > Do you have some sort of switching arangement for left/right engine
> > > alternators?
> > >
> > > Luc
> > >
> > >
> > > ----- Original Message -----
> > > From: "David J. Spencer" <djs@54Transmission.com>
> > > To: <avionics-list@matronics.com>
> > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > >
> > >
> > > > --> Avionics-List message posted by: "David J. Spencer"
> > > <djs@54Transmission.com>
> > > >
> > > > Luc...
> > > >
> > > > The resistance didn't change with a reverse in polarity... it rarely
> > does.
> > > >
> > > > My VOM has a 1 amp capability. When I set it to AC voltage and ran
a
> > > check
> > > > with the +/- cables I got .245 volt flow in either direction.
> > > >
> > > > You raise an interesting point about the two different types of
> > grounds...
> > > > power and audio. Both are separated in the wiring harness, but
> > connected
> > > to
> > > > the same center point ground. Should there be two center point
> grounds?
> > > >
> > > > Everything is very clean as I just rebuilt the wiring harness. I
have
> > had
> > > > it out twice and rechecked for faulty wiring or shielding touching
the
> > > > center wire and it checks out just fine.
> > > >
> > > > With the DC power source hooked directly to the power cable (I come
> off
> > > the
> > > > power bus with one power cable to the audio panel, 2 NavComs,
> > transponder,
> > > > ADF and intercom though another set of breakers) to the radio stack,
> the
> > > > only thing I eliminated was the battery and the associated wiring...
> all
> > > > other noise sources (motors, alternator, gyros, etc.) were always
off.
> > I
> > > > was getting the hum just off the battery power with no other motors,
> > > > solenoids, regulators, gyros or anything turned on even connected.
> > > >
> > > > The + cable was the one with the crimp in it. The negative cable is
> > only
> > > > about 18" long and connected to the frame.
> > > >
> > > > I have not checked the grounding strap from the engine to the
firewall
> > > > within the last two months, but will be checking that also along
with
> > the
> > > > starter cables, ammeter cables (which I found had some "burned
spots"
> on
> > > > them which was hidden from view until you "unbundled" all the
wiring)
> > and
> > > > installing an AmeriKing DC filter and Alternator filter. I've
always
> > > though
> > > >
> > > > Last year I replaced all the antenna cables as I found them to be
> > bundled
> > > > and taped to the + power cable. I also replaced all the comm
antennae
> > > > (fiberglass and cracked) with stainless steel, which helped a lot.
> The
> > > > controlled field I fly out of has a "cone of static" which many
> complain
> > > > about, but the FAA and FCC can't seem to isolate or do anything
about,
> > but
> > > > rather claim it's everybody's radios... when you lift off,
sometimes,
> > the
> > > > static is so bad you have to turn off the radios...
> > > >
> > > > I also replaced the alternator, voltage regulator and OV regulator
> plus
> > > all
> > > > the associated wiring as some Avionics moron had butt spliced the
> field
> > > wire
> > > > "INSIDE" the firewall cannon plug. The butt splice was broken and,
of
> > > > course, the field wire was going to ground. After 3 avionics shops
> > > checked
> > > > my alternator I took it out myself and found 3 diodes were bad...
> > > > AeroElectric found that one more was bad when they replaced my
> > alternator
> > > > with an upgraded version with larger bearings.
> > > >
> > > > Yesterday as I pulled out the + battery power cable, I found all the
> > > lights,
> > > > strobe, electric fuel pump, and fuel sensors taped (relatively new
> > looking
> > > > tape) to the + power cable. Needless to say, during it's 36 year
> > > existence,
> > > > maintenance has always been done in FAA certified shops and done
with
> a
> > > very
> > > > high level of poor quality.
> > > >
> > > > I honestly think this is a wiring problem relative to 36 y/o wire,
but
> I
> > > > won't know until I get all the wiring replaced and according to
Beech
> > > wiring
> > > > diagram specifications.
> > > >
> > > > Thanks for you help and input...
> > > >
> > > > David J. Spencer
> > > > Super3
> > > > djs@54Transmission.com
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: "Martini Luc J.R." <martini@foxinternet.net>
> > > > To: <avionics-list@matronics.com>
> > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > >
> > > >
> > > > > --> Avionics-List message posted by: "Martini Luc J.R."
> > > > <martini@foxinternet.net>
> > > > >
> > > > > What was the reverse polarity reading? I assume since you did
not
> > give
> > > a
> > > > > value for another range on the VOM, that it was a Digitial Type.
> > > > >
> > > > > Do you have a 1 amp Current meter? From the ohmic check, that's
> about
> > > the
> > > > > current you are drawing if this is a DC load. If not, hook a 100
> ohm
> > > > > resistor in series with the + battery Cable and measure the
voltage
> > > drop
> > > > > across the resistor.
> > > > >
> > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic
> contact)
> > > are
> > > > > EVERYTHING.
> > > > >
> > > > > However, there are frequently 2 ground levels, SIGNAL ground and
> POWER
> > > > > ground. Great care must be taken when assembling your avionics
to
> > keep
> > > > > these two seperate, and connect them only at a SINGLE POINT
ground.
> > > > >
> > > > > It is not a bad idea to stick your head under the panel, and clean
> the
> > > > > single point avionics ground to make sure the spade lugs and
washers
> > > are
> > > > > not oxidized (high ohmic contact)
> > > > >
> > > > > It does not surprise me that with EXTERNAL DC power, that you do
> NOT
> > > have
> > > > > radio hum. since your do NOT have a source of noise..
> > > > generator/alternator,
> > > > > motors, etc.
> > > > >
> > > > > You did not mention if it was the + or the - battery lead that had
a
> > > crimp
> > > > > splice in it. If it was in the + lead. other than creating a
> voltage
> > > > > drop... which would be reflected to the voltage regulator, i.e.
the
> > > > > generator/alternator would be putting out more voltage than it
> should
> > > > > because it senses a Battery slightly low voltage condition. If
on
> > the
> > > > > other hand it was on the - side. as far as the radios go, it
would
> be
> > > > like
> > > > > putting a resistance between the - battery terminal and Chasis
> Ground.
> > > > This
> > > > > could conceiveably cause the noise floor to be raised...but not
> likely
> > > if
> > > > > yourGenrator/Alternator grouind is good... By the way... have to
> > > checked
> > > > > that to make sure you have a good & clean grounding strap from the
> > > engine
> > > > to
> > > > > the firewall ??
> > > > >
> > > > > Luc
> > > > >
> > > > >
> > > > > ssage -----
> > > > > From: "David J. Spencer" <djs@54Transmission.com>
> > > > > To: <avionics-list@matronics.com>
> > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > > >
> > > > >
> > > > > > --> Avionics-List message posted by: "David J. Spencer"
> > > > > <djs@54Transmission.com>
> > > > > >
> > > > > > Luc...
> > > > > >
> > > > > > There was approximately 11 ohms between the + & - with the
correct
> > > > > polarity
> > > > > > hook up on the VOM.
> > > > > >
> > > > > > I took out the battery cable yesterday and found a split in the
> > > > insulation
> > > > > > about 3/8" long which had been taped over. The cable itself had
> > been
> > > > > > "crimped" creating a bulge and part of the internal wiring was
> > broken
> > > at
> > > > > > that point.
> > > > > >
> > > > > > As best I could tell this open area was not laying on the skin
but
> ,
> > > > > rather,
> > > > > > pointing away from the skin as the cable lay on the belly of the
> > > plane.
> > > > > >
> > > > > > This is being corrected with new wiring and proper attachments.
> > > > > >
> > > > > > I hooked the radios up to a DC power source i.e. they are
isolated
> > > from
> > > > > > anything (except the antenna)... and the hum went away.
> > > > > >
> > > > > > David J. Spencer
> > > > > > Super3
> > > > > > djs@54Transmission.com
> > > > > >
> > > > > > ----- Original Message -----
> > > > > > From: "Martini Luc J.R." <martini@foxinternet.net>
> > > > > > To: <avionics-list@matronics.com>
> > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > > > >
> > > > > >
> > > > > > > --> Avionics-List message posted by: "Martini Luc J.R."
> > > > > > <martini@foxinternet.net>
> > > > > > >
> > > > > > > What resistance do you read between the battery cable and
> ground.
> > > Be
> > > > > sure
> > > > > > > to take the measurement with the leads swapped as well as
> standard
> > > > > > polarity,
> > > > > > > i.e. red lead to + and black to -.. If you are NOT using a
> > digital
> > > > VOM,
> > > > > > > then also take values in both polarities in more than one
RANGE
> on
> > > the
> > > > > VOM
> > > > > > > (active devices - diodes /transistors - are non-linear.. give
> you
> > a
> > > > good
> > > > > > > clue if the value changes). You may have another noise
> suppression
> > > > diode
> > > > > > > somewhere, and/or an RC type (Band Pass) noise filter , with
> > > possibly
> > > > a
> > > > > > bad
> > > > > > > capacitor in it.
> > > > > > >
> > > > > > > Let me know what you get.
> > > > > > >
> > > > > > > Luc Martini
> > > > > > > ----- Original Message -----
> > > > > > > From: "David J. Spencer" <djs@54Transmission.com>
> > > > > > > To: <avionics-list@matronics.com>
> > > > > > > Subject: Avionics-List: Battery Solenoid (Relay)
> > > > > > >
> > > > > > >
> > > > > > > > --> Avionics-List message posted by: "David J. Spencer"
> > > > > > > <djs@54Transmission.com>
> > > > > > > >
> > > > > > > > Hi all...
> > > > > > > >
> > > > > > > > Has anyone ever replaced the battery relay on their Beech
> A23-24
> > > > Super
> > > > > > > III?
> > > > > > > >
> > > > > > > > My relay seems to work fine, but is 36 y/o and uses a
Kipvolt
> > > > Voltage
> > > > > > > > suppressor (diode) to eliminate voltage spikes flushing
> through
> > > the
> > > > > > > system.
> > > > > > > >
> > > > > > > > I am replacing the battery, ground and starter cables with
> new
> > > > cable
> > > > > > (AC
> > > > > > > > grade #0 wire for the 40 amp system) and am wondering if
> anyone
> > > has
> > > > > put
> > > > > > > in
> > > > > > > > a
> > > > > > > > new Aircraft grade battery relay from an aircraft supply
> > (Spruce)
> > > > > > source
> > > > > > > > battery relay in place of ours.
> > > > > > > >
> > > > > > > > I can currently remove the battery, diode and battery rely
> and
> > > get
> > > > > > > current
> > > > > > > > continuity (VOM) through the system from the positive
cable
> to
> > > the
> > > > > > > > negative cable or any
> > > > > > > > ground... everything is off... i.e switches, breaker etc.
> This
> > > is
> > > > > what
> > > > > > > > some
> > > > > > > > people think is causing a "hum" in the radios. The "hum"
is
> > > > present
> > > > > > with
> > > > > > > > the engine off and running the radios off a fully charged
> > > battery.
> > > > .
> > > > > > > > Additionally, using the AC voltage test setup on the VOM I
> can
> > > > detect
> > > > > > > > current flow between the positive cable and ground... any
> > ground.
> > > > > > > >
> > > > > > > >
> > > > > > > > I'm using certer point grounding, but all the avionics
manual
> > > > > articles
> > > > > > > > point
> > > > > > > > to RMI induced noise through the hull by poor shielding on
> the
> > DC
> > > > > power
> > > > > > > > lines.
> > > > > > > >
> > > > > > > > Beech doesn't seem to have these parts anymore.
> > > > > > > >
> > > > > > > > All comments welcomed...
> > > > > > > >
> > > > > > > > David J. Spencer
> > > > > > > > Super3
> > > > > > > > djs@54Transmission.com
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>
Message 3
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| Subject: | Re: Battery Solenoid (Relay) |
--> Avionics-List message posted by: "Martini Luc J.R." <martini@foxinternet.net>
Hi.
The "Vertical Strips" sound like a Log-Periodic antenna...Your best bet is
to get the assistance of a Ham Operator to ferit out the source of the noise
The AM/FM station on the field might be a problem. If that is is
transmission site, they could be spreading harmonic content (multiples of
their carrier and sideband frequencies) at relatively high power levels in
the general vicinity of the antenna.
The Ott cable to the Starter is a good idea. But 15 feet is still a very
long run. If ever you have to get another starter, go for one of the new
"Rare Earth Metal Magnet" types. These not only are smaller and lighter,
but they use significantly less current. The strong magnetic fields of the
Rare Earth Magnets, tighter tolerances of the Rotor to Field gap, greatly
reduce the losses in the motor, which in part are expressed as thermal loss
i.e. they don't get nearly as hot or as quick as the old boat anchers.
And,. less current draw means less line-loss in the power cable, means the
faster cranking speed, and no burnt wires and longer starter life.
The answer to your questions on static wicks and control surface bonding is
YES, if you fly in a relatively dry climate, and/or like to get up there
above the clouds, then static wicks can make a noticeable difference in
radio noise reduction and with that increase the effective range of the
radios. True, as you increase speed toward and above mach, the energy
imparted to the air causes ionication, but if you rub your pussy (cat)
across the plexiglass windshield (not recommended) you surely will also
create static.... The example I like to point out, is Electric Power
Transmission Lines. Many unfortunately uninformed linemen have been killed
by static discharge on the lines. They thought they were safe because they
knew that the power was off on the lines because they had pulled the circuit
breakers;. but, a slight dry wind blowing over miles of wire, creates
unbelieveably high static voltages with a very high peak current capability.
The wires act like the plates of a very large capacitor to ground.... ZAP!
Luc
----- Original Message -----
From: "David J. Spencer" <djs@54Transmission.com>
Subject: Re: Avionics-List: Battery Solenoid (Relay)
> --> Avionics-List message posted by: "David J. Spencer"
<djs@54Transmission.com>
>
> Luc...
>
> As far as magnetic deviation, I'm not aware of anything on the maps (and
> I've flown here for 30+ years) which indicates anything abnormal.
>
> Are you saying that static wicks and control surface bonding straps will
> increase the effective range of the radios? I don't have any problem with
> the cost of the wicks if they have advantages... I was just under the
> impression that unless you used a mach number as airspeed they didn't
> matter... wrong again.
>
> Yes other people have bitched about the static in the area... one
instructor
> says it is really irritating.
>
> I went by the airport last night and found that not only do we have the
TV,
> radio, microwave towers 5 miles south, we have a AM/FM radio station right
> on the field. That's the stuff on my wife's side of the plane that I
never
> look at. They have got 4 dish antennae, and some sort of vertical strip
> antenna (about 4-6 8' vertical strips per antenna and about three of
> these) on a 6 story building just off the airport property.
>
> In addition there is a fire station with it's radio system just off the
> perimeter and a cell phone tower about a 1/4 mile off the property.
>
> I don't know of any Ham operators in the area, but could probably find
some.
>
> Again thanks for the help...
>
> David
>
>
> ----- Original Message -----
> From: "Martini Luc J.R." <martini@foxinternet.net>
> To: <avionics-list@matronics.com>
> Subject: Re: Avionics-List: Battery Solenoid (Relay)
>
>
> > --> Avionics-List message posted by: "Martini Luc J.R."
> <martini@foxinternet.net>
> >
> > Glad to help out.
> >
> > I forgot to ask if there is a significant Magnetic Deviation in that
area
> > (what do they show on the maps?).. that would indicate an iron
> concentration
> > in the ground that could be acting as an RF shield. The effective range
> of
> > signals like VOR would also be decreased in such an area.
> >
> > As for Static wicks.. they never hurt, but are not all that cheap.
Static
> > discharge is more a function of humidity (altitude) than airspeed.
There
> > are 2
> > advantages to Static wicks in addition to possibly reducing radio noise
!)
> > is reduces galvanic corrosion..2) if you get hit by lightning, the tuffs
> > disappear instead of a piece of your flight control surfaces.
> > A lot of people don't realize that a plasma is not just a current, but
> > actually moves mater. The example I like to point out are the points in
> an
> > old distributor... No doubt you have noticed, that one side it builds a
> > mountain, and the other side a pit. The mountain and the pit are
always
> on
> > the same side of the points. Current flows from - to +. when you open
> the
> > points a plasma arc forms. The flow of electrons (which are pretty
light
> > but there are a lot of them and traveling at near the speed of
> > light. However, at the moment you open the circuit, the total energy in
> the
> > system must be equal, and you just stopped E=MC squared going that away
> > (toward the possitive terminal) instantaneously, For things to equal
out,
> > metal (mass) must flow in the opposite direction to equalize energy
state
> > equation. Electrons are light, so it does not take many atoms of
> > metal going much slower in the opposite direction for things to equal
out,
> > quenching the plasma. The result however is that the metal builds up
over
> > time on the - side of the points.. and that metal obviously comes from
the
> > + side.
> >
> > So, if your airplane is hit with lightning, the tuffs will vaporize...
In
> > military airplanes, they also provide bonding straps between the
fuselage
> > and the flight control surfaces, so that no arcing occurs in the
bearing/
> > bolts/pins that hold them on.
> >
> > For the radios, you might be surprised how much you gain is Effective
> Range
> > for your receivers.. you find you pick up VOR stations for example
quite
> a
> > few miles further out than before you spent your money and time on
> reducing
> > noise sources.
> >
> > I take it that other people have bitched about the noise problem in your
> > local area.
> >
> > With the advent of Cellphones, the general noise level have increased
> > dramatically. That is because cellphones are a SWITCHED System. When
> ever
> > you switch something on and off , you create noise. Take again for
> example,
> > the old car distributor with points. If you create a PLASMA, you are
> > radiating Radio Frequencies (Usually AM) , and as everyone knows, you
> > splatter AM noise
> > content all over the dial . If you SWITCH an RF signal on and off, the
> > amount of Noise content you generate is directly proportional to the
Rise
> > and Fall time of the pulse. The faster the switch things on and off,
the
> > worse it gets. A Zero Rise and Fall time,,, which is of course
> impossible,
> > would splatter equal amplitude from DC to Infinity. (and such noise
could
> > also be FM -harmonic content) So, in short,
> > cellphones suck for radio... They have been the bane of Broadcast TV
for
> > example..
> >
> > And, as you might have expected, if the Ambient Noise Level goes UP,
your
> > radio AGC compensates by turning the Signal Gain DOWN to compensate...
Not
> > nice!
> >
> > Do you by chance know any Ham Radio Operators in your area??? Those
guys
> > would be your best bet for finding the Noise SOURCE in the neighborhood.
> > There is an instrument called a Field Strength Meter, which is nothing
> more
> > than a Directional Antenna hooked to a TUNED Circuit, hooked up to an AM
> > detector (diode) and that in turn to a sensitive meter movement. In
> short,
> > a radio of sorts. They can go around and see where the strongest
signals
> > are coming from, and use their ham gear to see if the noise is strictly
AM
> > or possibly FM as well, and how much bandwidth is affected. THEN you
can
> go
> > to the guys causing the problem and threaten them with legal action if
> they
> > don't clean up their act and/or go to the FAA and FCC with evidence in
> hand
> > and bitch.
> >
> > Luc
> >
> >
> > ----- Original Message -----
> > From: "David J. Spencer" <djs@54Transmission.com>
> > To: <avionics-list@matronics.com>
> > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> >
> >
> > > --> Avionics-List message posted by: "David J. Spencer"
> > <djs@54Transmission.com>
> > >
> > > Wow... what a wealth of information... You will never know how much
> this
> > is
> > > helping and I really appreciate your input.
> > >
> > > First of all this is a single engine plane (1967 Beech Musketeer, 200
hp
> > > Lycoming with fuel injection, A23-24 or Super III), so I only have one
> > > alternator. Now to the cycling which I mentioned. The VR was a
contact
> > > type which I replaced with a Zeftronic unit. The cycling continued.
I
> > then
> > > replaced the OV regulator with the matched Zeftronic solid state
affair
> > and
> > > the cycling has stopped. I thought it might be one or the other as
> > nothing
> > > except the alternator and intercom were running when I last got fed up
> > with
> > > the noise.
> > >
> > > Turn off the alternator and the noise went away. It just made sense
and
> > the
> > > VR & OV were both original equipment and 36+ years old.
> > >
> > > Thank you... You are correct for correcting me about resistance with
or
> > > without inline devices... I just wasn't thinking when I said there is
no
> > > difference as I always try to simplify the circuit to it's barest
> > essentials
> > > and then load on devices until I find a problem. Just my untrained
> > > methodology.
> > >
> > > I will run the amperage test when I get some new battery cable
> installed.
> > I
> > > bought #4 as it met the continuous usage requirements as per the chart
> on
> > > page 1-10 of Robert G. Horan's "Avionics Installation Handbook"...
> > HOWEVER,
> > > the plane came with #0 wire and I am going to replace it with #0 wire.
> > The
> > > run from the battery to the starter solenoid is about 12 feet (12 volt
> > > system) and then another 5 feet to the starter. The alternator is a
40
> > amp
> > > unit, but my guess is that the amperage on engine start may be high
> enough
> > > to warrant the heavier cable. Anyway what the hell it's just money
and
> it
> > > "might" prevent something I don't understand is going on... safe is
> better
> > > than crispy.
> > >
> > > Now to the audio panel. I have a Terra TMA 230 with a marker beacon
and
> > two
> > > Terra TXN-960 NavComs with glide slopes and ILS which I call a radio
> > stack.
> > > I also have a KLN-88, cooling fan, King KT-76 transponder, Sigtronics
> > > SPA-400 intercom and Collins RCR-650/IND 650 ADF. The audio panel has
> > three
> > > audio grounds (connected) and one chassis ground.
> > >
> > > AND THANK YOU VERY MUCH -- YOU JUST JOGGED MY MEMORY-- THE GROUNDS
FOR
> > THE
> > > ADF, TRANSPONDER & COOLING FAN ARE NOT ON THE CENTERPOINT SYSTEM. I
> also
> > > have not put a ground on the radio trays themselves... I think I
should.
> > >
> > > Also, my centerpoint system is a terminal block where all the posts
are
> > > connected to the same frame point as the ground. This allowed me to
> > create
> > > a neat little area where all the grounds (except the ones I just
> > mentioned)
> > > are located. The intercom requires insulating all the headset jacks
> (with
> > > isolation washers) and using the centerpoint ground.
> > >
> > > Now to the Cone of Static... below is a diagram of the airport in
> > > relationship to some 1600' AGL radio, TV & Microwave transmission
towers
> > > which are South of the field about 5 miles. The airport is directly
> > between
> > > the towers and Downtown Dallas Texas. Is it possible that the towers
> > could
> > > be transmitting a directional signal toward downtown?
> > >
> > >
> > > ++++
> > >
> > > +++++ Radio Transmission towers (~15 @ 1600' AGL)
> > >
> > > +++++
> > >
> > >
> > about
> > > five miles to towers
> > >
> > >
> > > |
> > > |
> > > | Runway
> > (17/35)
> > > |
> > > |
> > >
> > >
> > > about three miles
> > >
> > > DOWNTOWN DALLAS TEXAS
> > >
> > > As for large metallic structures...there are two hangars built by
Howard
> > > Hughes for something really big right on the 17/35 runway. Other than
> > that
> > > there is an FBI/U.S. Customs helicopter hangar (which tends to be
rather
> a
> > > secretive place) on the South end of the field and a medium sized
strip
> > mall
> > > just across a highway to the South. There is also a six story Wells
> Fargo
> > > Bank down by the FBI.
> > >
> > > There is a National Guard Armory on the West side of the field which,
I
> > > believe has some radio antennae sticking up in the wooded area
adjacent
> to
> > > it... I'll check on the way home. My wife (she's a pilot also) says
> she
> > > thinks the bank tower has dish antennae on it... either the bank or
the
> > FBI.
> > > That's her side of the plane so I never look out there, because I
don't
> > want
> > > to see what she's going to hit, and will check on it on way home.
> > >
> > > The antennas are well grounded, but are on the aft slope of the top of
> the
> > > fuselage (fuselage much like a V-35 Bonanza). After putting in the
ADF
> > > which required triaxial cable I changed EVERYTHING to triaxial as it
> just
> > > seemed the logical thing to do.
> > >
> > > They are too close together (about 2 feet apart), but are about 5 feet
> aft
> > > of the Loran antenna. The transponder is under the foward fuselage
> (blade
> > > type) and the ADF & marker beacon are on the bottom aft fuselage. The
> > > aftmost comm antenna is very close to the vertical stabilizer which
has
> an
> > > ABS plastic shroud on the leading edge to affect airflow. I never
> thought
> > > much about the static from plastic as all I've read indicates that our
> > plane
> > > is too slow... we cruise at ~145-150 mph with take-off and climb at
> 90-100
> > > mph. Should I install some static wicks?
> > >
> > > We only get this static garbage at this airport... no where else we
have
> > > flown has given us any problems and we have been into some strange
> places
> > > like the Arizona & New Mexico desert and along the U.S./ Mexico
border.
> > >
> > > You will never know how much you are helping... I tend to be a rather
> > > tenacious person and want very much to understand as much as possible
> > about
> > > what is going on and how to eliminate it... if possible.
> > >
> > > David
> > >
> > >
> > > ----- Original Message -----
> > > From: "Martini Luc J.R." <martini@foxinternet.net>
> > > To: <avionics-list@matronics.com>
> > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > >
> > >
> > > > --> Avionics-List message posted by: "Martini Luc J.R."
> > > <martini@foxinternet.net>
> > > >
> > > > Hello again
> > > >
> > > > There can be a very considerable difference in resitance readings of
a
> > VOM
> > > > for forward v. reverse polarity if you have an "Active Device" in
the
> > > > circuit... i.e. a Diode, or a Transistor. Looking from the battery,
> > you
> > > > could be looking at several of these, (diodes or transistors) which
> are
> > > > used for noise suppression, voltage spike protection, even
> internally
> > in
> > > a
> > > > voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not
isolated
> by
> > a
> > > > circuit breaker.
> > > >
> > > > If there is No change as you indicated, that simply verifies that
you
> > > likely
> > > > DO NOT have an Active Device in the Battery Bus Circuit, since
Active
> > > > Devices are very NON LINEAR, i.e., the reading you get on a VOM is
> > > typically
> > > > MUCH higher in one polarity than the other.
> > > >
> > > > If your VOM has a 1 amp direct reading capability, the way to
proceed
> > is
> > > to
> > > > disconnected the + lead from the battery. Set your VOM to DC
CURRENT
> > > > (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in
> SERIES
> > > > with the battery, i.e., VOM - lead to battery cable (where the LOAD
> is),
> > > and
> > > > + lead to the battery + lead (Current Source).
> > > >
> > > > The reading you will get will be in either MILLIAMPS (ma) or AMPS
> (A)..
> > > > depending on your meter...if the scale is calibrated in (ma), move
> the
> > > > decimal place to the right 3 spaces (X 1000) for (amps)
> > > >
> > > > If you are using your fully charged aircraft battery,. you should
get
> > > 1.09
> > > > Amps showing on the meter.:
> > > >
> > > > 12 VDC/11 OHMS = 1.09 AMPS.
> > > >
> > > > Note that if you use external power the voltage might be higher, up
> to
> > 14
> > > > volts.. that might damage your VOM since that is 1.3 Amps.
> > > >
> > > > You may have done this already according to your note, but you read
> the
> > > > VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each
meter
> > is
> > > > different, I have no way of knowing what the .245 you referred to
> really
> > > is.
> > > >
> > > > The nice thing about using a CURRENT METER is that you can leave it
> > hooked
> > > > up and go disconnect various things that power goes to, i.e voltage
> > > > regulators, bulkhead connectors, circuit breakers, etc. and with a
> quick
> > > > check see if the current dropped to ZERO.... BINGO... your problem
is
> in
> > > > THAT CIRCUIT.
> > > >
> > > > As to your question about Avionics Signal and Power Grounds. NO,
they
> > > MUST
> > > > be connected together at ONE and ONLY one place for noise
immunity...
> > > also
> > > > helps with lighning protection. Signal ground is not the same as
> AUDIO
> > > > ground.
> > > >
> > > > That is not to say that Avionics Shops do things right... as you
have
> > > found
> > > > out.
> > > >
> > > > There is one other thing I should tell you about. Audio Panels are
an
> > > even
> > > > MORE complicated item. In Audio Panels, they may have as many as 2
> MORE
> > > > types of Grounds. King (KMA-24) is famous for this. You have to
> Isolate
> > > the
> > > > AUDIO GROUNDS as well. and may have to isolate the Pilot and
Co-pilot
> > > audio
> > > > from ANY OTHER audio ground, as well as isolation from CHASIS
GROUND.
> > > > These suckers can be real bears, and the source of Noise PICKUP
(from
> > > > external sources such as motors, sparks (like bad shielding on spark
> > plug
> > > > wires) and even external to the aircraft.. industrial sources.
> > > >
> > > > The Noise Zone you mention is intriguing. There are two ways of
> looking
> > > at
> > > > the problem.. 1) that there exists a NOISE SOURCE in that area, or
2),
> > > that
> > > > there exists a SHIELD from radiation.
> > > >
> > > > I believe the first is what everybody has been focused on. However,
> the
> > > > second is just as likely if not more so. For example, if there is a
> > > > significant magnetic disturbance in the area, or a very large
metalic
> > > > structure in the area, or a hill with a lot of iron content.. etc.
> etc.
> > > > these can shield the background RF Noise Level The Automatic Gain
> > > Control
> > > > (AGC) circuits in you radios, and/or audio panel, would compensate
by
> > > > INCREASING the GAIN... that would result in audio STATIC...exactly
> like
> > > what
> > > > you get when listening to your AM radio in the car when you drive
> > through
> > > a
> > > > tunnel.
> > > >
> > > > I got the point you made that you had EVERYTHING disconnected
except
> > the
> > > > Battery and the Avionics DC bus and of course the radios that power
> > them..
> > > > One thing you should also do, is turn of your Transponder. Also, if
> the
> > > > Antenna Coax for the Transponder and the DME (if you have one) are
> run
> > > > parallel with other wiring bundles, that can be a source of severe
> > static.
> > > > I always use Double Shielded Coax for these devices... some Av
Shops
> do
> > > > not... and if I have to cross a wire bundle, I do it at as close to
90
> > > > degrees as I can.(the Electric and Magnetic Fields no not couple to
> the
> > > > other cable when; you do that) Obviously it pays to keep these
Coax
> > > leads
> > > > as short as possible (but must generally be no shorter than 3 feet
> (1/2
> > > wave
> > > > length).
> > > >
> > > > Another general practice to follow is good GROUND PLANES for the
> > antennas.
> > > > What that means generally, is as much flat metal around the antenna
as
> > > your
> > > > airplane and avionics can afford; keep radiating elements like DME
> and
> > > > Transponder seperated by 6' from each other.. as well as from very
low
> > > > signal sources like LORAN, GPS...Keep the Comm antenna away from
those
> > as
> > > > well... and strangely enough, keep these well away and UP-STREAM
> > > > (airstream) from non-electrically conductive surfaces such as
> > Plexiglass,
> > > > Fiberglass etc. (these create static electricity that can couple the
> > > > discharge via inonizatiotion of the airstream) Then, have a Good
Low
> > > ohmic
> > > > contact for the antennas. That means cleaning away all paint where
> the
> > > > antenna mounts, and Alodining the area. and on the INSIDE of the
> > > airplane,
> > > > make sure that your have a good clean contact in like fashion for
the
> > > > antenna mounting nuts/bolts.
> > > >
> > > > I just received another e-mail from you... about the odd charging
> habits
> > > of
> > > > your airplane. Keep in mind, that a fully charged battery is 12
VDC.
> > > > However, your voltage regulator puts out between 13.5 and 14.00
volts
> > > > depending on the current draw, and the internal setting of you
voltage
> > > > regulator. You would be surprised at the variation in "Idling
Current"
> > > from
> > > > one Regulator to the next. So, it does NOT surprise me that even
> after
> > > > starting your engines with a full battery, that they do a little
> chargin
> > > for
> > > > a while. What DOES surprise me is the CYCLING you mentioned. That
> was
> > > > common in the old days of RELAY type voltage regulagtors, but NOT
for
> > > Solid
> > > > state Alternator Regulators.
> > > >
> > > > Do you have some sort of switching arangement for left/right engine
> > > > alternators?
> > > >
> > > > Luc
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: "David J. Spencer" <djs@54Transmission.com>
> > > > To: <avionics-list@matronics.com>
> > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > >
> > > >
> > > > > --> Avionics-List message posted by: "David J. Spencer"
> > > > <djs@54Transmission.com>
> > > > >
> > > > > Luc...
> > > > >
> > > > > The resistance didn't change with a reverse in polarity... it
rarely
> > > does.
> > > > >
> > > > > My VOM has a 1 amp capability. When I set it to AC voltage and
ran
> a
> > > > check
> > > > > with the +/- cables I got .245 volt flow in either direction.
> > > > >
> > > > > You raise an interesting point about the two different types of
> > > grounds...
> > > > > power and audio. Both are separated in the wiring harness, but
> > > connected
> > > > to
> > > > > the same center point ground. Should there be two center point
> > grounds?
> > > > >
> > > > > Everything is very clean as I just rebuilt the wiring harness. I
> have
> > > had
> > > > > it out twice and rechecked for faulty wiring or shielding touching
> the
> > > > > center wire and it checks out just fine.
> > > > >
> > > > > With the DC power source hooked directly to the power cable (I
come
> > off
> > > > the
> > > > > power bus with one power cable to the audio panel, 2 NavComs,
> > > transponder,
> > > > > ADF and intercom though another set of breakers) to the radio
stack,
> > the
> > > > > only thing I eliminated was the battery and the associated
wiring...
> > all
> > > > > other noise sources (motors, alternator, gyros, etc.) were always
> off.
> > > I
> > > > > was getting the hum just off the battery power with no other
motors,
> > > > > solenoids, regulators, gyros or anything turned on even connected.
> > > > >
> > > > > The + cable was the one with the crimp in it. The negative cable
is
> > > only
> > > > > about 18" long and connected to the frame.
> > > > >
> > > > > I have not checked the grounding strap from the engine to the
> firewall
> > > > > within the last two months, but will be checking that also along
> with
> > > the
> > > > > starter cables, ammeter cables (which I found had some "burned
> spots"
> > on
> > > > > them which was hidden from view until you "unbundled" all the
> wiring)
> > > and
> > > > > installing an AmeriKing DC filter and Alternator filter. I've
> always
> > > > though
> > > > >
> > > > > Last year I replaced all the antenna cables as I found them to be
> > > bundled
> > > > > and taped to the + power cable. I also replaced all the comm
> antennae
> > > > > (fiberglass and cracked) with stainless steel, which helped a lot.
> > The
> > > > > controlled field I fly out of has a "cone of static" which many
> > complain
> > > > > about, but the FAA and FCC can't seem to isolate or do anything
> about,
> > > but
> > > > > rather claim it's everybody's radios... when you lift off,
> sometimes,
> > > the
> > > > > static is so bad you have to turn off the radios...
> > > > >
> > > > > I also replaced the alternator, voltage regulator and OV regulator
> > plus
> > > > all
> > > > > the associated wiring as some Avionics moron had butt spliced the
> > field
> > > > wire
> > > > > "INSIDE" the firewall cannon plug. The butt splice was broken
and,
> of
> > > > > course, the field wire was going to ground. After 3 avionics
shops
> > > > checked
> > > > > my alternator I took it out myself and found 3 diodes were bad...
> > > > > AeroElectric found that one more was bad when they replaced my
> > > alternator
> > > > > with an upgraded version with larger bearings.
> > > > >
> > > > > Yesterday as I pulled out the + battery power cable, I found all
the
> > > > lights,
> > > > > strobe, electric fuel pump, and fuel sensors taped (relatively new
> > > looking
> > > > > tape) to the + power cable. Needless to say, during it's 36 year
> > > > existence,
> > > > > maintenance has always been done in FAA certified shops and done
> with
> > a
> > > > very
> > > > > high level of poor quality.
> > > > >
> > > > > I honestly think this is a wiring problem relative to 36 y/o wire,
> but
> > I
> > > > > won't know until I get all the wiring replaced and according to
> Beech
> > > > wiring
> > > > > diagram specifications.
> > > > >
> > > > > Thanks for you help and input...
> > > > >
> > > > > David J. Spencer
> > > > > Super3
> > > > > djs@54Transmission.com
> > > > >
> > > > >
> > > > > ----- Original Message -----
> > > > > From: "Martini Luc J.R." <martini@foxinternet.net>
> > > > > To: <avionics-list@matronics.com>
> > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > > >
> > > > >
> > > > > > --> Avionics-List message posted by: "Martini Luc J.R."
> > > > > <martini@foxinternet.net>
> > > > > >
> > > > > > What was the reverse polarity reading? I assume since you did
> not
> > > give
> > > > a
> > > > > > value for another range on the VOM, that it was a Digitial Type.
> > > > > >
> > > > > > Do you have a 1 amp Current meter? From the ohmic check, that's
> > about
> > > > the
> > > > > > current you are drawing if this is a DC load. If not, hook a
100
> > ohm
> > > > > > resistor in series with the + battery Cable and measure the
> voltage
> > > > drop
> > > > > > across the resistor.
> > > > > >
> > > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic
> > contact)
> > > > are
> > > > > > EVERYTHING.
> > > > > >
> > > > > > However, there are frequently 2 ground levels, SIGNAL ground and
> > POWER
> > > > > > ground. Great care must be taken when assembling your avionics
> to
> > > keep
> > > > > > these two seperate, and connect them only at a SINGLE POINT
> ground.
> > > > > >
> > > > > > It is not a bad idea to stick your head under the panel, and
clean
> > the
> > > > > > single point avionics ground to make sure the spade lugs and
> washers
> > > > are
> > > > > > not oxidized (high ohmic contact)
> > > > > >
> > > > > > It does not surprise me that with EXTERNAL DC power, that you do
> > NOT
> > > > have
> > > > > > radio hum. since your do NOT have a source of noise..
> > > > > generator/alternator,
> > > > > > motors, etc.
> > > > > >
> > > > > > You did not mention if it was the + or the - battery lead that
had
> a
> > > > crimp
> > > > > > splice in it. If it was in the + lead. other than creating a
> > voltage
> > > > > > drop... which would be reflected to the voltage regulator, i.e.
> the
> > > > > > generator/alternator would be putting out more voltage than it
> > should
> > > > > > because it senses a Battery slightly low voltage condition. If
> on
> > > the
> > > > > > other hand it was on the - side. as far as the radios go, it
> would
> > be
> > > > > like
> > > > > > putting a resistance between the - battery terminal and Chasis
> > Ground.
> > > > > This
> > > > > > could conceiveably cause the noise floor to be raised...but not
> > likely
> > > > if
> > > > > > yourGenrator/Alternator grouind is good... By the way... have
to
> > > > checked
> > > > > > that to make sure you have a good & clean grounding strap from
the
> > > > engine
> > > > > to
> > > > > > the firewall ??
> > > > > >
> > > > > > Luc
> > > > > >
> > > > > >
> > > > > > ssage -----
> > > > > > From: "David J. Spencer" <djs@54Transmission.com>
> > > > > > To: <avionics-list@matronics.com>
> > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > > > >
> > > > > >
> > > > > > > --> Avionics-List message posted by: "David J. Spencer"
> > > > > > <djs@54Transmission.com>
> > > > > > >
> > > > > > > Luc...
> > > > > > >
> > > > > > > There was approximately 11 ohms between the + & - with the
> correct
> > > > > > polarity
> > > > > > > hook up on the VOM.
> > > > > > >
> > > > > > > I took out the battery cable yesterday and found a split in
the
> > > > > insulation
> > > > > > > about 3/8" long which had been taped over. The cable itself
had
> > > been
> > > > > > > "crimped" creating a bulge and part of the internal wiring was
> > > broken
> > > > at
> > > > > > > that point.
> > > > > > >
> > > > > > > As best I could tell this open area was not laying on the skin
> but
> > ,
> > > > > > rather,
> > > > > > > pointing away from the skin as the cable lay on the belly of
the
> > > > plane.
> > > > > > >
> > > > > > > This is being corrected with new wiring and proper
attachments.
> > > > > > >
> > > > > > > I hooked the radios up to a DC power source i.e. they are
> isolated
> > > > from
> > > > > > > anything (except the antenna)... and the hum went away.
> > > > > > >
> > > > > > > David J. Spencer
> > > > > > > Super3
> > > > > > > djs@54Transmission.com
> > > > > > >
> > > > > > > ----- Original Message -----
> > > > > > > From: "Martini Luc J.R." <martini@foxinternet.net>
> > > > > > > To: <avionics-list@matronics.com>
> > > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay)
> > > > > > >
> > > > > > >
> > > > > > > > --> Avionics-List message posted by: "Martini Luc J.R."
> > > > > > > <martini@foxinternet.net>
> > > > > > > >
> > > > > > > > What resistance do you read between the battery cable and
> > ground.
> > > > Be
> > > > > > sure
> > > > > > > > to take the measurement with the leads swapped as well as
> > standard
> > > > > > > polarity,
> > > > > > > > i.e. red lead to + and black to -.. If you are NOT using a
> > > digital
> > > > > VOM,
> > > > > > > > then also take values in both polarities in more than one
> RANGE
> > on
> > > > the
> > > > > > VOM
> > > > > > > > (active devices - diodes /transistors - are non-linear..
give
> > you
> > > a
> > > > > good
> > > > > > > > clue if the value changes). You may have another noise
> > suppression
> > > > > diode
> > > > > > > > somewhere, and/or an RC type (Band Pass) noise filter , with
> > > > possibly
> > > > > a
> > > > > > > bad
> > > > > > > > capacitor in it.
> > > > > > > >
> > > > > > > > Let me know what you get.
> > > > > > > >
> > > > > > > > Luc Martini
> > > > > > > > ----- Original Message -----
> > > > > > > > From: "David J. Spencer" <djs@54Transmission.com>
> > > > > > > > To: <avionics-list@matronics.com>
> > > > > > > > Subject: Avionics-List: Battery Solenoid (Relay)
> > > > > > > >
> > > > > > > >
> > > > > > > > > --> Avionics-List message posted by: "David J. Spencer"
> > > > > > > > <djs@54Transmission.com>
> > > > > > > > >
> > > > > > > > > Hi all...
> > > > > > > > >
> > > > > > > > > Has anyone ever replaced the battery relay on their Beech
> > A23-24
> > > > > Super
> > > > > > > > III?
> > > > > > > > >
> > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a
> Kipvolt
> > > > > Voltage
> > > > > > > > > suppressor (diode) to eliminate voltage spikes flushing
> > through
> > > > the
> > > > > > > > system.
> > > > > > > > >
> > > > > > > > > I am replacing the battery, ground and starter cables
with
> > new
> > > > > cable
> > > > > > > (AC
> > > > > > > > > grade #0 wire for the 40 amp system) and am wondering if
> > anyone
> > > > has
> > > > > > put
> > > > > > > > in
> > > > > > > > > a
> > > > > > > > > new Aircraft grade battery relay from an aircraft supply
> > > (Spruce)
> > > > > > > source
> > > > > > > > > battery relay in place of ours.
> > > > > > > > >
> > > > > > > > > I can currently remove the battery, diode and battery
rely
> > and
> > > > get
> > > > > > > > current
> > > > > > > > > continuity (VOM) through the system from the positive
> cable
> > to
> > > > the
> > > > > > > > > negative cable or any
> > > > > > > > > ground... everything is off... i.e switches, breaker
etc.
> > This
> > > > is
> > > > > > what
> > > > > > > > > some
> > > > > > > > > people think is causing a "hum" in the radios. The "hum"
> is
> > > > > present
> > > > > > > with
> > > > > > > > > the engine off and running the radios off a fully charged
> > > > battery.
> > > > > .
> > > > > > > > > Additionally, using the AC voltage test setup on the VOM
I
> > can
> > > > > detect
> > > > > > > > > current flow between the positive cable and ground... any
> > > ground.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > I'm using certer point grounding, but all the avionics
> manual
> > > > > > articles
> > > > > > > > > point
> > > > > > > > > to RMI induced noise through the hull by poor shielding
on
> > the
> > > DC
> > > > > > power
> > > > > > > > > lines.
> > > > > > > > >
> > > > > > > > > Beech doesn't seem to have these parts anymore.
> > > > > > > > >
> > > > > > > > > All comments welcomed...
> > > > > > > > >
> > > > > > > > > David J. Spencer
> > > > > > > > > Super3
> > > > > > > > > djs@54Transmission.com
> > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>
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