Today's Message Index:
----------------------
1. 03:53 AM - Re: Kitfox-List Digest: 16 Msgs - 02/08/10 (Mark Napier (napierm))
2. 05:29 AM - Re: Static port instruction sheets (Lynn Matteson)
3. 05:31 AM - Pitot Static Ports (Paul Franz - Merlin GT)
4. 06:34 AM - Re: Radio Noise (Noel Loveys)
5. 06:36 AM - Re: Radio Noise (Noel Loveys)
6. 06:54 AM - Re: Intermittent Ignition Issue (Noel Loveys)
7. 07:00 AM - Re: Radio Noise (John W. Hart)
8. 07:37 AM - Re: Intermittent Ignition Issue (Tom Jones)
9. 11:02 AM - Re: Radio Noise (Clint Bazzill)
10. 11:37 AM - Re: Intermittent Ignition Issue (Guy Buchanan)
11. 02:33 PM - Re: Pitot Static Ports (Noel Loveys)
12. 02:47 PM - Re: Radio Noise (Noel Loveys)
13. 03:09 PM - Re: Radio Noise (Noel Loveys)
14. 04:02 PM - Re: Radio Noise (John W. Hart)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | RE: Kitfox-List Digest: 16 Msgs - 02/08/10 |
http://www.scandinavian-kitfoxes.se/technical/kitfox-doc/Static-system.p
df
Time: 04:12:30 PM PST US
Subject: Kitfox-List: Re: Kitfox-List Digest: Static port location
From: "WurlyBird" <james.t.trizzino@us.army.mil>
So why not just post it right here?
--------
James
Kitfox 3 / 582 / GSC prop
The ink is still drying on my new certificate
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=285505#285505
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Static port instruction sheets |
Thanks for posting that, Mark....I had forgotten all about the "or
somebody gooses you" part of the instructions. That alone was worth
the price of admission. : )
I'm going to copy those instructions and leave them lay on my
workbench in hopes it'll cause my (lost) original instructions to
come out of hiding.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 849.1 hrs
Countdown to 1000 hrs~151 to go
Sensenich 62"x46" Wood (summer)
Sensenich 55.5" x 46" Wood (winter)
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying (and learning)
do not archive
On Feb 9, 2010, at 5:55 AM, Mark Napier (napierm) wrote:
> <napierm@cisco.com>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Pitot Static Ports |
On Tue, February 9, 2010 2:55 am, Mark Napier (napierm) wrote:
>
> <http://www.scandinavian-kitfoxes.se/technical/kitfox-doc/Static-system.pdf>
>
> Time: 04:12:30 PM PST US
> Subject: Kitfox-List: Re: Kitfox-List Digest: Static port location
> From: "WurlyBird" <james.t.trizzino@us.army.mil>
>
> So why not just post it right here?
If you're like me and read the frequent problems with the above Skystar designed
static port mostly because of location, why not use a well designed static port.
But
first, before I show you a couple, have a look at how these thing work.
<http://en.wikipedia.org/wiki/Pitot_tube>
The sensors are made as either static only, total pressure only or combined static
and
total pressure. From what I see in the above Kitfox instructions is they use a
total
pressure sensor in the left wing and a dual port static sensor in the rear part
of the
fuselage. If you are satisfied with the total pressure sensor then you might want
to
get a fabricated static sensor such as Type PS shown here:
<http://www.unitedsensorcorp.com/pitot.html>
I am going to use a combined static and total pressure sensor more like the Type
PA
shown in the above URL. The discussion of errors is worth reading and understanding
so
you are aware of error produced by pitch and yaw, especially.
Here are some useful discussion items related to the errors in measurement due
to
where the static sensor holes are placed in the tube.
<http://www.flowkinetics.com/measurement.htm>
Given this information, maybe this will contribute to building a better mousetrap,
so
to speak. At least your understanding level of the sensig problem should be improved.
As you can see, due to especially boundary layer effects, the SS design falls short.
However it probably can be lauded for simplicity and low drag.
--
Paul A. Franz
Registration/Aircraft - N14UW/Merlin GT
Engine/Prop - Rotax 914/NSI CAP
Bellevue WA
"How did it happen? How did our national government grow from a servant
with sharply limited powers into a master with virtually unlimited power?
In part, we were swindled. There are occasions when we have elevated men
and political parties to power that promised to restore limited government
and then proceeded, after their election, to expand the activities of
government. But let us be honest with ourselves. Broken promises are not
the major causes of our trouble. Kept promises are. All too often we have
put men in office who have suggested spending a little more on this, a
little more on that, who have proposed a new welfare program, who have
thought of another variety of 'security.' We have taken the bait,
preferring to put off to another day the recapture of freedom and the
restoration of our constitutional system. We have gone the way of many a
democratic society that has lost its freedom by persuading itself that if
'the people' rule, all is well."
-- Barry Goldwater (1909-1998), former Arizona U.S. Senator
The safety of the republic being the supreme law, and Texas having
offered us the key to the safety of our country from all foreign
intrigues and diplomacy, I say accept the key... and bolt the door
at once.
-- Andrew Jackson
"A free people [claim] their rights as derived from the laws of nature,
and not as the gift of their chief magistrate."
-- Thomas Jefferson, Rights of British America, 1774
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Yes. Com transmitters on aircraft use a basic vertical design antenna.
They require a ground plane to direct the radio waves in a horizontal,
omni-directional direction. On metal aircraft the mounting lug for the
antenna has a place for the shield to be attached. At the transmitter end
it is grounded to the frame of the radio. On cloth planes there is usually
a steel support under the cloth for the mount to attach. Again the coax is
connected to the ground side of the mount.
On cloth planes it is recommended that a foil ground plane be installed on
the inside of the cloth. Many times operators who find they have poor range
on their com radios will have installations with no ground plane. When
attaching the ground plane to the inside of the cloth you really want to be
careful that the glue you use won't dissolve the dope on your cloth my
recommendation would be to install the ground plane when the fuselage is
being covered so it will be held in place with the dope.
Newer composite planes may have their antennae actually moulded into the
skins of the planes. For instance a jet liner may have the com antennae
moulded as a vertical dipole inside the leading edge of the vertical
stabilizer. In that case the ground plane may not be actually grounded but
the coax shield will be connected to a radiator equal in length to the
centre radiator. Gone are the days of the loop antennas and sense wires out
in the breeze where they slow down the plane and increase fuel consumption.
In all the vertical antenna types with the different feeds the one thing
that is consistent is the centre radiator of the coax must never be
grounded!
Jet liners may also have complex antenna for HF (high frequency) operation.
Smaller planes may have a wire which is extended out behind the plane for HF
operation. Designing ground planes for those antennae can be difficult.
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Paul Franz -
Merlin GT
Sent: February 9, 2010 12:24 AM
Subject: RE: Kitfox-List: Radio Noise
<paul@eucleides.com>
On Mon, February 8, 2010 7:02 pm, Noel Loveys wrote:
>
> Antennae are a bit different they are unbalanced conductors where the
> shielding carries up to half the power. Antennae should be grounded at
both
> ends.
Noel, are you certain of that? I am looking at the installation guide for a
Narco
VOR/COM given to me from the Paine Field Radio shop and it says to ground
the Com coax
on one end only at the radio end of the shielding of the coax. I seem to
recall
reading the same advice on the AeroElectric list. I'm not speaking from
Engineering
knowledge just regurgitating so I definitely won't feel hurt if I'm
corrected on this.
--
Paul A. Franz
Registration/Aircraft - N14UW/Merlin GT
Engine/Prop - Rotax 914/NSI CAP
Bellevue WA
"It is an object of vast magnitude that systems of education should
be adopted and pursued which may not only diffuse a knowledge of the
sciences but may implant in the minds of the American youth the
principles of virtue and of liberty and inspire them with just and
liberal ideas of government and with an inviolable attachment to
their own country."
-- Noah Webster, On Education of Youth in America, 1790
"Absolute power corrupts even when exercised for humane purposes. The
benevolent despot who sees himself as a shepherd of the people still
demands from others the submissiveness of sheep. The taint inherent in
absolute power is not its inhumanity but its anti-humanity."
-- American author Eric Hoffer (1902-1983)
"That [tyrannical government] power is absolute, minute, regular,
provident and mild. It would be like the authority of a parent if,
like that authority, its object was to prepare men for manhood; but
it seeks, on the contrary, to keep them in perpetual childhood: it
is well content that the people should rejoice, provided they think
of nothing but rejoicing. For their happiness such a government
willingly labors, but it chooses to be the sole agent and the only
arbiter of that happiness; it provides for their security, foresees
and supplies their necessities, facilitates their pleasures, manages
their principal concerns, directs their industry, regulates the
descent of property, and subdivides their inheritances: what
remains, but to spare them all the care of thinking and all the
trouble of living?"
-- French historian Alexis de Tocqueville (1805-1859)
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Right on!
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson
Sent: February 9, 2010 12:51 AM
Subject: Re: Kitfox-List: Radio Noise
This all boils down to my favorite thought:
If it don't work, try something else.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 849.1 hrs
Countdown to 1000 hrs~151 to go
Sensenich 62"x46" Wood (summer)
Sensenich 55.5" x 46" Wood (winter)
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying (and learning)
On Feb 8, 2010, at 9:21 PM, Noel Loveys wrote:
>
> When it comes to electronics there are rules and just like
> everything else
> there are exceptions that make the rules.
>
> Noel
>
>
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Intermittent Ignition Issue |
The good news is there are no brushes in the 582 magneto... It has a big
magnet on the end of the crank. All the coils are static in they are
mounted to the engine case.
The bad news is you can have an open in either a coil or one of the trigger
units that tell the CDI when to fire.
You can download all the manuals on your engine here
http://www.rotax-owner.com/index.php?option=com_content
<http://www.rotax-owner.com/index.php?option=com_content&view=article&id=108
&Itemid=25> &view=article&id=108&Itemid=25
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of
riquenkelly@aol.com
Sent: February 9, 2010 1:52 AM
Subject: Kitfox-List: Intermittent Ignition Issue
Listers,
I am out of ideas. I have a Model IV with a 582 and Ducati ignition.
About 50% of the time my aircraft fails ground check on one side of my
ignition. I have checked for every loose connection I can think of. How
frequently have the brushes on the flywheel failed? Could they be
intermittent? I have replaced the DCI I thought was the failed unit but I'm
not sure how likely it is for a DCI to fire intermittently.
Does anyone have any good suggestions? I've checked everything I can think
of...
Thanks for the help,
Rique Gwin
Kitfox Model IV Classic
582 Grey
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
DC ground, or RF ground???
John Hart
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Noel Loveys
Sent: Tuesday, February 09, 2010 8:34 AM
Subject: RE: Kitfox-List: Radio Noise
"In all the vertical antenna types with the different feeds the one thing
that is consistent is the centre radiator of the coax must never be
grounded!"
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Intermittent Ignition Issue |
> I am out of ideas. I have a Model IV with a 582 and Ducati ignition. About 50%
of the time my aircraft fails ground check on one side of my ignition.
Rique, what happens to fail the mag check? Is it too much RPM drop or no RPM drop
on one side? If one side is bad the engine should quit when you turn the
good side off.
--------
Tom Jones
Classic IV
503 Rotax, 72 inch Two blade Warp
Ellensburg, WA
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=285627#285627
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
You have got to be joking.
Clint
> From: noelloveys@yahoo.ca
> To: kitfox-list@matronics.com
> Subject: RE: Kitfox-List: Radio Noise
> Date: Mon=2C 8 Feb 2010 22:51:20 -0330
>
>
> Shielding... grounded only to the end closest to the source.. If you grou
nd
> the shield at both ends what you have done is made an unbalanced conducto
r
> like a piece of coax. As with coax there is a capacitance in the line whe
n
> it is grounded at both ends. This is why they say to only ground at one e
nd
> and that end usually has the best ground at the source end.
>
> Years ago I was involved in a volunteer position at the local cable stati
on.
> We did several programs which were all recorded on 1/2" Beta video machin
es
> and then edited down to the program length. Our editing suite had a probl
em
> that after a video dub of five minutes we would get a glitch in our video
.
> The suite was in a room with a faraday screen that was connected to a clo
se
> to perfect ground ( a 4X8'piece of steel buried ten feet below the surfac
e
> of the ground... The steel had 20'radials attached to it) Sony was so
> upset over this they actually sent technicians from Japan to check out ou
r
> installation. After a week of trying everything they could think of one o
f
> the technicians attached an additional ground between the frame of the vi
deo
> board and one of the audio boards and the glitch stopped. No one knows wh
y
> since both boards were properly grounded. The bond between the two boards
> worked so well that future models of the Beta editing suite had the extra
> ground included.
>
> When it comes to electronics there are rules and just like everything els
e
> there are exceptions that make the rules.
>
> Noel
>
>
>
> -----Original Message-----
> From: owner-kitfox-list-server@matronics.com
> [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteso
n
> Sent: February 8=2C 2010 7:38 PM
> To: kitfox-list@matronics.com
> Subject: Re: Kitfox-List: Radio Noise
>
>
> In the interest of opening a can of worms=2C Noel........shielding
> grounded on one end or both? (ducking) : )
>
>
> Lynn Matteson
> Kitfox IV Speedster=2C taildragger
> Jabiru 2200=2C #2062=2C 849.1 hrs
> Countdown to 1000 hrs~151 to go
> Sensenich 62"x46" Wood (summer)
> Sensenich 55.5" x 46" Wood (winter)
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying (and learning)
> do not archive
>
>
>
>
>
> On Feb 8=2C 2010=2C at 4:58 PM=2C Noel Loveys wrote:
>
> > Just to be sure... There should be a grounded shield on the P-
> > Leads The only time the P-Leads themselves should be grounded is to
> > shut off the mags. When the engine is in operation they should be
> > adrift meaning they are actually like little transmitter antennas.
> > It is important they be shielded.
> >
> >
> >
> > Noel
> >
> >
> >
> > From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-
> > list-server@matronics.com] On Behalf Of Roger McConnell
> > Sent: February 7=2C 2010 10:53 AM
> > To: kitfox-list@matronics.com
> > Subject: RE: Kitfox-List: Radio Noise
> >
> >
> >
> > Guy and Noel=2C
> >
> > Thanks for the advice. After old man winter eases up around here I
> > will check these out. I really think it's something to do with the
> > ignition system or a bad ground on a P-lead.
> >
> > DO NOT ARCHIVE
> >
> >
> >
> > Roger McConnell=2C Duncan=2C OK
> >
> > Model 7 Trigear=2C Rotax 912uls
> >
> > Flying sense Jan. 06
> >
> >
> >
> > http://www.matronics.com/Navigator?Kitfox-List http://
> > forums.matronics.com http://www.matronics.com/contribution http://
> > www.matronics.com/Navigator?Kitfox-Listhttp://
> > forums.matronics.comhttp://www.matronics.com/contribution
> > =======================
> > =======================
> > =======================
===========
>
>
>
>
>
>
>
>
===========
===========
===========
===========
>
>
>
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Intermittent Ignition Issue |
At 09:21 PM 2/8/2010, you wrote:
>Does anyone have any good suggestions? I've checked everything I
>can think of...
Rique,
Two things from the historical files:
1. There have been instances of broken wires between the stator and
the DCI's. These were broken inside the cover and very difficult to
find. Try manipulating the wires vigorously while the engine's
running while hopefully staying out of the prop. (One more reason to
have a clutch.)
2. I had a plug wire back out of the DCI. They're screwed on like
plug caps and can fail. It was only found on disassembly because the
cover held it in place. It doesn't sound like this is the problem
because you would have corrected it when you replaced the DCI.
Guy Buchanan
San Diego, CA
K-IV 1200 / 582-C / Warp / 400 hrs. and counting
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Pitot Static Ports |
Many other aircraft use the static port on the side of the fuselage. There
was even a jet in south America that crashed because the static ports, which
are also connected to the altimeter and VSI, were covered with tape for
painting on the pilot side. As both systems in the jet were separate there
was a discontinuity between the pilot and co-pilot instruments... They
stalled in the dark. Oh yes on a jet the same probes are used it's just
they are connected to a flight computer that drives the panel instruments.
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Paul Franz -
Merlin GT
Sent: February 9, 2010 9:58 AM
Subject: Kitfox-List: Pitot Static Ports
<paul@eucleides.com>
On Tue, February 9, 2010 2:55 am, Mark Napier (napierm) wrote:
<napierm@cisco.com>
>
>
<http://www.scandinavian-kitfoxes.se/technical/kitfox-doc/Static-system.pdf>
>
> Time: 04:12:30 PM PST US
> Subject: Kitfox-List: Re: Kitfox-List Digest: Static port location
> From: "WurlyBird" <james.t.trizzino@us.army.mil>
>
> So why not just post it right here?
If you're like me and read the frequent problems with the above Skystar
designed
static port mostly because of location, why not use a well designed static
port. But
first, before I show you a couple, have a look at how these thing work.
<http://en.wikipedia.org/wiki/Pitot_tube>
The sensors are made as either static only, total pressure only or combined
static and
total pressure. From what I see in the above Kitfox instructions is they use
a total
pressure sensor in the left wing and a dual port static sensor in the rear
part of the
fuselage. If you are satisfied with the total pressure sensor then you might
want to
get a fabricated static sensor such as Type PS shown here:
<http://www.unitedsensorcorp.com/pitot.html>
I am going to use a combined static and total pressure sensor more like the
Type PA
shown in the above URL. The discussion of errors is worth reading and
understanding so
you are aware of error produced by pitch and yaw, especially.
Here are some useful discussion items related to the errors in measurement
due to
where the static sensor holes are placed in the tube.
<http://www.flowkinetics.com/measurement.htm>
Given this information, maybe this will contribute to building a better
mousetrap, so
to speak. At least your understanding level of the sensig problem should be
improved.
As you can see, due to especially boundary layer effects, the SS design
falls short.
However it probably can be lauded for simplicity and low drag.
--
Paul A. Franz
Registration/Aircraft - N14UW/Merlin GT
Engine/Prop - Rotax 914/NSI CAP
Bellevue WA
"How did it happen? How did our national government grow from a servant
with sharply limited powers into a master with virtually unlimited power?
In part, we were swindled. There are occasions when we have elevated men
and political parties to power that promised to restore limited government
and then proceeded, after their election, to expand the activities of
government. But let us be honest with ourselves. Broken promises are not
the major causes of our trouble. Kept promises are. All too often we have
put men in office who have suggested spending a little more on this, a
little more on that, who have proposed a new welfare program, who have
thought of another variety of 'security.' We have taken the bait,
preferring to put off to another day the recapture of freedom and the
restoration of our constitutional system. We have gone the way of many a
democratic society that has lost its freedom by persuading itself that if
'the people' rule, all is well."
-- Barry Goldwater (1909-1998), former Arizona U.S. Senator
The safety of the republic being the supreme law, and Texas having
offered us the key to the safety of our country from all foreign
intrigues and diplomacy, I say accept the key... and bolt the door
at once.
-- Andrew Jackson
"A free people [claim] their rights as derived from the laws of nature,
and not as the gift of their chief magistrate."
-- Thomas Jefferson, Rights of British America, 1774
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
I'm not too sure that I understand the question. The whole airframe should
be DC grounded in as much as it should be bonded to the negative lug on the
battery. All the cases of all the instruments should be grounded to this
and the it can also serve as the ground plane. Battery operated
transmitters that have vertical antennas need not have the ground planes
attached to the negative terminal of the battery other than through the
coaxial shielding.
The rubber duck antennae that a lot of hand held radios use are a separate
antenna on their own they use a coil to approximate a load to the radio
without having a ground plane however I have used the side of a trailer as a
signal reflector on a vhf radio to be able to transmit over a hundred miles
on 1/10th of a watt. The signal was strong enough to open a repeater site
and allow me to access an auto patch to make a phone call.
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of John W. Hart
Sent: February 9, 2010 11:30 AM
Subject: RE: Kitfox-List: Radio Noise
DC ground, or RF ground???
John Hart
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Noel Loveys
Sent: Tuesday, February 09, 2010 8:34 AM
Subject: RE: Kitfox-List: Radio Noise
"In all the vertical antenna types with the different feeds the one thing
that is consistent is the centre radiator of the coax must never be
grounded!"
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Sorry Clint but no I was only trying to illustrate that some things
especially electronics work for unknown reasons.
Noel
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Clint Bazzill
Sent: February 9, 2010 3:30 PM
Subject: RE: Kitfox-List: Radio Noise
You have got to be joking.
Clint
> From: noelloveys@yahoo.ca
> To: kitfox-list@matronics.com
> Subject: RE: Kitfox-List: Radio Noise
> Date: Mon, 8 Feb 2010 22:51:20 -0330
>
>
> Shielding... grounded only to the end closest to the source.. If you
ground
> the shield at both ends what you have done is made an unbalanced conductor
> like a piece of coax. As with coax there is a capacitance in the line when
> it is grounded at both ends. This is why they say to only ground at one
end
> and that end usually has the best ground at the source end.
>
> Years ago I was involved in a volunteer position at the local cable
station.
> We did several programs which were all recorded on 1/2" Beta video
machines
> and then edited down to the program length. Our editing suite had a
problem
> that after a video dub of five minutes we would get a glitch in our video.
> The suite was in a room with a faraday screen that was connected to a
close
> to perfect ground ( a 4X8'piece of steel buried ten feet below the surface
> of the ground... The steel had 20'radials attached to it) Sony was so
> upset over this they actually sent technicians from Japan to check out our
> installation. After a week of trying everything they could think of one of
> the technicians attached an additional ground between the frame of the
video
> board and one of the audio boards and the glitch stopped. No one knows why
> since both boards were properly grounded. The bond between the two boards
> worked so well that future models of the Beta editing suite had the extra
> ground included.
>
> When it comes to electronics there are rules and just like everything else
> there are exceptions that make the rules.
>
> Noel
>
>
>
> -----Original Message-----
> From: owner-kitfox-list-server@matronics.com
> [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson
> Sent: February 8, 2010 7:38 PM
> To: kitfox-list@matronics.com
> Subject: Re: Kitfox-List: Radio Noise
>
>
> In the interest of opening a can of worms, Noel........shielding
> grounded on one end or both? (ducking) : )
>
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062, 849.1 hrs
> Countdown to 1000 hrs~151 to go
> Sensenich 62"x46" Wood (summer)
> Sensenich 55.5" x 46" Wood (winter)
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying (and learning)
> do not archive
>
>
>
>
>
> On Feb 8, 2010, at 4:58 PM, Noel Loveys wrote:
>
> > Just to be sure... There should be a grounded shield on the P-
> > Leads The only time the P-Leads themselves should be grounded is to
> > shut off the mags. When the engine is in operation they should be
> > adrift meaning they are actually like little transmitter antennas.
> > It is important they be shielded.
> >
> >
> >
> > Noel
> >
> >
> >
> > From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-
> > list-server@matronics.com] On Behalf Of Roger McConnell
> > Sent: February 7, 2010 10:53 AM
> > To: kitfox-list@matronics.com
> > Subject: RE: Kitfox-List: Radio Noise
> >
> >
> >
> > Guy and Noel,
> >
> > Thanks for the advice. After old man winter eases up around here I
> > will check these out. I really think it's something to do with the
> > ignition system or a bad ground on a P-lead.
> >
> > DO NOT ARCHIVE
> >
> >
> >
> > Roger McConnell, Duncan, OK
> >
> > Model 7 Trigear, Rotax 912uls
> >
> > Flying sense Jan. 06
> >
> >
> >
> > http://www.matronics.com/Navigator?Kitfox-List http://
> > forums.matronics.com http://www.matronics.com/contribution http://
> > www.matronics.com/Navigator?Kitfox-Listhttp://
> > forums.matronics.comhttp://www.matronics.com/contribution
> > =================================== _-
> > ========== _-
> > contribution_-
> > ==================================
>
>
> = Archive Search & Download, 7-Day Browse, Chat, FAQ,
&g===
>
>
>
Message 14
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
On many vertical radiators, that produce gain in comparison to a 1/4 wave
radiator, the impedance matching coils for such antennae put the center
conductor of the feed coaxial cable at DC ground potential. In other words,
if you place one probe of an ohm meter on the radiator, and touch the other
one to chassis ground, you will read continuity, hence the center conductor
of the coaxial cable is at DC ground potential. It will not be at RF ground
potential.
John Hart
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Noel Loveys
Sent: Tuesday, February 09, 2010 4:46 PM
Subject: RE: Kitfox-List: Radio Noise
I'm not too sure that I understand the question. The whole airframe should
be DC grounded in as much as it should be bonded to the negative lug on the
battery. All the cases of all the instruments should be grounded to this
and the it can also serve as the ground plane. Battery operated
transmitters that have vertical antennas need not have the ground planes
attached to the negative terminal of the battery other than through the
coaxial shielding.
The rubber duck antennae that a lot of hand held radios use are a separate
antenna on their own they use a coil to approximate a load to the radio
without having a ground plane however I have used the side of a trailer as a
signal reflector on a vhf radio to be able to transmit over a hundred miles
on 1/10th of a watt. The signal was strong enough to open a repeater site
and allow me to access an auto patch to make a phone call.
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of John W. Hart
Sent: February 9, 2010 11:30 AM
Subject: RE: Kitfox-List: Radio Noise
DC ground, or RF ground???
John Hart
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Noel Loveys
Sent: Tuesday, February 09, 2010 8:34 AM
Subject: RE: Kitfox-List: Radio Noise
"In all the vertical antenna types with the different feeds the one thing
that is consistent is the centre radiator of the coax must never be
grounded!"
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|