Today's Message Index:
----------------------
1. 01:52 AM - Re: Ergonomics (was: Flap switches/relay) ()
2. 03:50 AM - Re: Garmin GNS 530 Installation Manual (Dave)
3. 04:09 AM - Re: Nexus M9177/4-1 (Michael Hinchcliff)
4. 06:39 AM - Re: Old Man's Musings (Olen Goodwin)
5. 07:04 AM - Paul and other thoughts (Crapse, Richard W (Rick), WWCS)
6. 07:10 AM - Re: Re: Old Man's Musings (OldBob Siegfried)
7. 08:00 AM - Re: Paul and other thoughts (RV Builder (Michael Sausen))
8. 08:14 AM - Re: Paul and other thoughts (Brian Lloyd)
9. 09:23 AM - Re: Paul and other thoughts (Terry Watson)
10. 09:40 AM - Re: Marketing research question Annunciated Parameters (Condrey, Bob (US SSA))
11. 11:20 AM - Noise filter noise (James Redmon)
12. 11:38 AM - Offal (Fergus Kyle)
13. 12:36 PM - Strobe /beacon question. (rlnelson5)
14. 01:54 PM - Problems with High EGT readings (Ron Patterson)
15. 03:01 PM - Princeton capacitance converters -- RV-7 (William Gill)
16. 03:08 PM - Re: Strobe /beacon question. (FLYaDIVE@aol.com)
17. 03:23 PM - Re: Noise filter noise (FLYaDIVE@aol.com)
18. 04:54 PM - Re: flap deployment above Vfe (Jon & Kathryn Hults)
19. 05:36 PM - Re: Noise filter noise (Brian Lloyd)
20. 05:37 PM - Re: Problems with High EGT readings (Brian Lloyd)
21. 05:57 PM - Re: Noise filter noise (Dave N6030X)
22. 07:02 PM - Re: Problems with High EGT readings (FLYaDIVE@aol.com)
23. 07:32 PM - Re: Problems with High EGT readings (Jim Baker)
24. 07:45 PM - Re: Problems with High EGT readings (James Freeman)
25. 07:49 PM - Re: Problems with High EGT readings (Kelly McMullen)
26. 08:14 PM - Re: Problems with High EGT readings (OldBob Siegfried)
27. 08:14 PM - Re: Problems with High EGT readings (John D.Heath)
28. 08:33 PM - Re: Problems with High EGT readings (Matt Prather)
29. 08:47 PM - Re: Problems with High EGT readings (Brian Lloyd)
30. 09:55 PM - Re: Noise filter noise (James Redmon)
31. 10:01 PM - Re: Noise filter noise (James Redmon)
32. 10:06 PM - Re: Noise filter noise (James Redmon)
Message 1
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Subject: | Flap switches/relay) |
Speed Brakes vs. Spoilers. If they are wind spoilers the kill lift in a big way
and would be more of an issue than a body mounted speed brake.
I put the flap switch on my RV-4 stick grip (MAC grip). To reduce the chance
of accidental deployment I cut the mini-toggle switch down very very short, so
to operate, you put your thumb on top to move it. It was also spring loaded to
up.
The MAC grip standard toggle switch lever, although small still got caught on
things and caused accidental deployment. After cut down you still had to be careful
and not rest things on top of the stick. The trim buttons where there and
the PTT on the front.
I WILL NOT DO ALL THE BUTTONS ON THE GRIP ON MY NEW PROJECT.
My new project, RV-7 has the flap switch (and trim) on the panel near the throttle/prop/mixture.
The wiring is way simple and the heavy duty flap switch can
handle the flap motor with out troublesome relays.
George RV-4, RV-7
>Subject: RE: Ergonomics (was: AeroElectric-List: Flap switches/relay
wiring)
>From: "Matt Prather" <mprather@spro.net>
>
>Speed brakes are usually very small drag producers that provide energy
>control while at high indicated airspeeds. Once slowed to a low
>airspeed, speed brakes represent a very small portion of airframe drag.
>Sometimes, takeoff performance isn't even particularly degraded with the brakes
>extended.
>
>Regards, Matt-
---------------------------------
Get your own web address for just $1.99/1st yr. We'll help. Yahoo! Small Business.
Message 2
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Subject: | Re: Garmin GNS 530 Installation Manual |
--> AeroElectric-List message posted by: Dave <dave@abrahamson.net>
You may have the following but JIC... I cannot find the installation
manual, but I know for sure that Stark avionics has it cuz I called
with a 430 question and Tony accidentally looked at the 530 manual
first. Don't know whether he has paper copy or online version.
<http://www.garmin.com/manuals/%7Binsert>http://www.garmin.com/manuals/GNS530_PilotsGuide.pdf
GNS530_ApprovedFlightManualSupplement.PDF
GNS530_QuickReferenceGuide.pdf
GNS530_LBAApprovedFlightManualSupplement.pdf
Message 3
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Subject: | Re: Nexus M9177/4-1 |
Bob, this is perfect. I've added froogle.com to my list of search
engines for shopping. Thank you!
Do not archive.
Michael H.
~~~~~~~~~~~~~~~~~~~
Hi Michael,
I did a froogle search on TJT-102 and found it at skygeek
http://stylespilotshop.stores.yahoo.net/jb-11v.html for $18.95.
I don't know anything about the company.
Hope this helps,
Bob W.
On Thu, 24 Aug 2006 18:48:56 -0500
"Michael Hinchcliff" <cfi@conwaycorp.net> wrote:
> Can somebody tell me where I can buy a single Nexus TJT-102 also
known as a M9177/4-1 female adapter? These are used by
Allied-Signal/Honeywell panel-mounted GPS products as a data loader
port. I have the PC data cable with the male end, but I need the female
end to mount in the instrument panel. I contacted the manufacturer and
they won't sell me less than 50 at a time. Their direct distributors
are the same. Here are the manufacturer's specs:
http://nexinc.thomasnet.com/item/all-categories/telephone-jacks/tjt-102?&
seo=110 If I can't find one, I'll just hard-wire an 9 pin sub-d port
instead.
>
>
>
> Thanks,
>
> Michael H.
>
--
http://www.bob-white.com
N93BD - Rotary Powered BD-4 (first engine start 1/7/06)
Custom Cables for your rotary installation -
http://www.roblinphoto.com/shop/
Message 4
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Subject: | Re: Old Man's Musings |
Bob, I'll be going into the 200/300. Probably a good thing, since I
won't have to learn the glass and automation of the 400.
Olen
Message 5
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Subject: | Paul and other thoughts |
--> AeroElectric-List message posted by: "Crapse, Richard W (Rick), WWCS" <rwcrapse@att.com>
I read the thread with Paul and I have to laugh. It reminds me of
another situation with Dave Atkins and redrives for Rotary engines. He
uses a spur gear setup because "planetary gears won't hold up". Tracy
Crook took the engineers way and did a failure analysis on the same
redrive design. Funny , they came to different conclusions. Lack of a
thrust bearing and incorrect lubrication paths led to the Ross redrive
killing itself, not the gear design is what Tracy found. This thing with
Paul and Bob smacks of the same vein.
I had the opportunity to read Bob's book, attend his seminar, and attend
Greg Richter's seminar at OshKosh. Now here is another holy war that
goes on. Bob and Greg will disagree with me on this, but I found it
fascinating that they are aruging the same point on wiring aircraft and
ground paths from two separate view points. They call it different
things, but the gist is there. Greg prefers the solder and heat shrink
tube, Bob prefers the Fast-On connectors. Both want a gas tight,
electrically sound connection. Both talk about shielding and how to do
it correctly. Bob likes fuses, Greg likes polyfuses. Differing thoughts,
but both have their valid points. As someone who deals with the mighty
invisible heart of radio (vacuum tubes) and who deals with SMT, TTL,
CMOS devices, I can say that in SOME applications, one version of
technology is superior to another, but not universally. For example,
vacuum tube diodes are far quieter than their counterpart solid state
brothers. However, does it justify using the vacuum tube diode in modern
radio gear? If we are talking about a Hi-Fi amp or stereo, I personally
like the sound of the older tube types that the solid state does not
match. But then again, when dealing with aircraft radios and modern HT's
versus battery life versus vibration, the solid state works just fine,
thank-you very much. In sand storm conditions? Give me the vaccum tube
finals, they could care less about the static charges, makes them glow
brighter. And before you argue that they are dead, the next gen is
coming out a nano tubes with cold cathodes for satellites. Now isn't
that a surprise?
I try to learn from everybody, but I always have to understand where
they are coming from first and why. Much better education that way.
Rick
Message 6
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Subject: | Re: Old Man's Musings |
--> AeroElectric-List message posted by: OldBob Siegfried <oldbob@beechowners.com>
You will love it!
Happy Skies,
Old Bob
Do Not Archive
--- Olen Goodwin <ogoodwin@comcast.net> wrote:
> Bob, I'll be going into the 200/300. Probably a
> good thing, since I won't have to learn the glass
> and automation of the 400.
>
> Olen
Message 7
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Subject: | Paul and other thoughts |
--> AeroElectric-List message posted by: "RV Builder (Michael Sausen)" <rvbuilder@sausen.net>
Great post Rick and spot on. I tend to liken it to old skool vs new
skool. Neither method is wrong but they would rather spend the time
arguing why one is more correct than the other. Waaaay too much
rhetoric. Yawn.
Michael Sausen
RV-10 #352 Buildus Interuptus due to moving
Do Not Archive
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Crapse, Richard W (Rick), WWCS
Sent: Friday, August 25, 2006 9:03 AM
Subject: AeroElectric-List: Paul and other thoughts
--> AeroElectric-List message posted by: "Crapse, Richard W (Rick),
--> WWCS" <rwcrapse@att.com>
I read the thread with Paul and I have to laugh. It reminds me of
another situation with Dave Atkins and redrives for Rotary engines. He
uses a spur gear setup because "planetary gears won't hold up". Tracy
Crook took the engineers way and did a failure analysis on the same
redrive design. Funny , they came to different conclusions. Lack of a
thrust bearing and incorrect lubrication paths led to the Ross redrive
killing itself, not the gear design is what Tracy found. This thing with
Paul and Bob smacks of the same vein.
I had the opportunity to read Bob's book, attend his seminar, and attend
Greg Richter's seminar at OshKosh. Now here is another holy war that
goes on. Bob and Greg will disagree with me on this, but I found it
fascinating that they are aruging the same point on wiring aircraft and
ground paths from two separate view points. They call it different
things, but the gist is there. Greg prefers the solder and heat shrink
tube, Bob prefers the Fast-On connectors. Both want a gas tight,
electrically sound connection. Both talk about shielding and how to do
it correctly. Bob likes fuses, Greg likes polyfuses. Differing thoughts,
but both have their valid points. As someone who deals with the mighty
invisible heart of radio (vacuum tubes) and who deals with SMT, TTL,
CMOS devices, I can say that in SOME applications, one version of
technology is superior to another, but not universally. For example,
vacuum tube diodes are far quieter than their counterpart solid state
brothers. However, does it justify using the vacuum tube diode in modern
radio gear? If we are talking about a Hi-Fi amp or stereo, I personally
like the sound of the older tube types that the solid state does not
match. But then again, when dealing with aircraft radios and modern HT's
versus battery life versus vibration, the solid state works just fine,
thank-you very much. In sand storm conditions? Give me the vaccum tube
finals, they could care less about the static charges, makes them glow
brighter. And before you argue that they are dead, the next gen is
coming out a nano tubes with cold cathodes for satellites. Now isn't
that a surprise?
I try to learn from everybody, but I always have to understand where
they are coming from first and why. Much better education that way.
Rick
Message 8
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Subject: | Re: Paul and other thoughts |
--> AeroElectric-List message posted by: Brian Lloyd <brian-av@lloyd.com>
On Aug 25, 2006, at 7:02 AM, Crapse, Richard W (Rick), WWCS wrote:
> I had the opportunity to read Bob's book, attend his seminar, and
> attend
> Greg Richter's seminar at OshKosh. Now here is another holy war that
> goes on. Bob and Greg will disagree with me on this, but I found it
> fascinating that they are aruging the same point on wiring aircraft
> and
> ground paths from two separate view points. They call it different
> things, but the gist is there.
When we were creating the technology that became the Internet, we ran
into the same problem. Brilliant people would argue their points
vociferously and nearly come to blows. It would usually take an
equally-bright third party to determine that they were saying the
same thing but using different words. The difference was usually in
the inconsequential details. We even came up with a name for the
phenomenon: agreeing violently.
So I just shrugged and decided that Bob and Greg, and Bob and Paul
were just agreeing violently ... for the most part.
But when things like this happen I usually look for whoever has the
simplest solution.
I am going to go meet Bob tomorrow at Auburn. I have been
corresponding with him for ten years and have never met him face-to-
face. It should be interesting.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
Message 9
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Subject: | Paul and other thoughts |
--> AeroElectric-List message posted by: "Terry Watson" <terry@tcwatson.com>
No, I disagree. There was much more to it than that. Paul was consistently
attacking the honesty and integrity of Bob's work, misquoting what he said
and attacking that. Bob kept trying to bring it back to the point. This has
been going on, off and on, for at least a year. Each time Paul goes off in a
huff after getting in at least a half a dozen different "last word"
messages. Paul kept trying to make it personal; Bob kept trying to get it
back to the point.
Finally, Bob asked Paul to leave the list that Matt created for Bob to use
to answer our questions about wiring little airplanes. In my mind, he waited
about 18 months too long. Paul has wasted way too many people's time. I
think I heard somewhere that he has his own list, but apparently no one was
listening to him their so he had to come pollute this one again.
Terry
--> AeroElectric-List message posted by: "RV Builder (Michael Sausen)"
<rvbuilder@sausen.net>
<snip> Neither method is wrong but they would rather spend the time
arguing why one is more correct than the other.<snip>
Michael Sausen
RV-10 #352 Buildus Interuptus due to moving
Do Not Archive
Message 10
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Subject: | Re: Marketing research question Annunciated Parameters |
Has anything ever come of the annunciator panel?
Bob
RV-10 #40105
Message 11
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Subject: | Noise filter noise |
--> AeroElectric-List message posted by: "James Redmon" <james@berkut13.com>
Hi all,
I'm wondering if someone could educate me a little on something I
encountered while trying to eliminate electrical noise coming from an
autopilot servo. The story goes like this:
I recently installed a new autopilot servo in my Berkut (all composite). It
worked perfectly, but for some reason, the servo makes a loud squealing
noise in the intercom audio when it's activated. I did all the usual
things - changed ground points, increased grounding, double checked
shielding on cables, un-bundled wires, ferrite beads on the cables, etc.
The only thing that really worked was to power the servo from a separate
battery - indicating electrical propagation, not RF. I spoke with the
manufacturer, and they did mention that there was a 2.5KHz PWM signal that
is used to control the servo, and that the "noise" I hear is likely that.
So, on to trying to isolate the servo from everything else...right.
I first tried (at the manufacturer's request) a pair of capacitors (.1uf and
4700uf) in parallel, grounded off the servo power lead itself. This did
slightly dampen the noise, but certainly not enough. So, I also went out
and purchased a common 10-amp car audio power filter - just like those sold
by Radio Shack and documented by Bob on his site - 2 caps with a choke coil
potted in a case although I can not see the ratings on the caps. I placed
the filter in an orientation that isolated the power source from the servo,
instead of servo from power source as IT was the verified source of the
noise.
The good news is, that filter eliminated about 99% of the noise - and that's
good to go. I have not yet done extensive tests to see if the AP now
operates properly in flight with the filter in-line (possible I/O errors,
proper servo feedback, etc)...that's coming soon. But, I want to explore
the "weirdness" first.
Now, the weird (to me anyway) part is that the filter itself now audibly
"sings" with the same frequency that I had heard before on the intercom. I
mean, it literally makes the noise like a speaker would. Is this normal?
What would be causing that? Is this symptomatic of some additional problem
that might effect servo operation? Something else I should do or try?
All information and education is welcome...but remember, I'm not an EE. ;-)
Eager to learn,
James Redmon
Berkut #013 N97TX
http://www.berkut13.com
By the way, this is not a common situation as the manufacturer has not seen
this type of issue before...although they are doing everything they can to
get this under control - under warranty, to their credit! I have no issues
with the way they are handling this..so please don't pester me about that
part.
Message 12
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--> AeroElectric-List message posted by: "Fergus Kyle" <VE3LVO@rac.ca>
I am in complete agreement with Pereira's attitude regarding the
ankle-biting remarks, chewing out Nuckolls' remarks for sport. The only
difference 'tween us is: He says it so much more diplomatically.
The simple truth is Bob can lay down the basis for comprehension by
us no-nods whereas attempting to shoot him down does none of us any good at
all. We've been at this for a number of years and boobs popping up with
vexing offal occur from time to time.
"Its time to say good by to this line of discussion
Paul"
In your case that time was six months ago.........
Ferg Kyle
Europa A064 914 Classic
do not archive
Message 13
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Subject: | Strobe /beacon question. |
--> AeroElectric-List message posted by: "rlnelson5" <rlnelson-5@peoplepc.com>
Hello, I have a Whalen power pack that will drive 4 units. I have aquired 2 wing
tip, 1 tail and 1 red beacon. I would like some feedback as how to wire this
up. I could just wire it as a 4 way strobe on 1 switch. I was thinking that it
might be better to wire this so that the beacon goes on first and then adding
the rest of the strobes with another switch or perhaps a 2-10 type switch. I
m not sure how to do that since the power pack will have to be powered for anything
to work. I was thinking it would be good to shut off the strobes in fog/clouds
but still leave the red beacon going. Is this a good idea or just more
work then needed?
Thanks
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=57330#57330
Message 14
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Subject: | Problems with High EGT readings |
Hey all,
I've just begun to have 1450+ EGT readings on all cylinders, while the CHT's remain
below 390 degrees. No attempt to richen things up (carb heat for example)
improves things. I took off the cowl and see no exterior signs of trouble, removed
spark plugs and they are nice and tan and even wet from running too rich.
I tried a brief flight and all was normal, then on the next long leg they did
it again. I recycled the Grand Rapids EIS and then only one cylinder persisted
in giving me this reading. Am I right to assume it is an indicator/gauge issue
or am I missing something more ominous?
Thanks in advance for your ideas.
Ron
RV-4 N8ZD
Message 15
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Subject: | Princeton capacitance converters -- RV-7 |
Hello All,
I had planned to mount these capacitance converters on the sub-panel,
but the shielded wire is slightly too short if routed where it will
remain out of view. So, the current plan is to mount them between the
seat ribs. Has anyone else mounted them between the seat ribs?
Pros/Cons/any pictures? Thanks in advance for your input.
Have a great weekend,
Bill
RV-7 wiring
Lee's Summit, MO.
Message 16
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Subject: | Re: Strobe /beacon question. |
--> AeroElectric-List message posted by: FLYaDIVE@aol.com
In a message dated 8/25/06 3:40:31 PM Eastern Daylight Time,
rlnelson-5@peoplepc.com writes:
> Hello, I have a Whalen power pack that will drive 4 units. I have aquired 2
> wing tip, 1 tail and 1 red beacon. I would like some feedback as how to
wire
> this up. I could just wire it as a 4 way strobe on 1 switch. I was thinking
> that it might be better to wire this so that the beacon goes on first and
> then adding the rest of the strobes with another switch or perhaps a 2-10
> type switch. I m not sure how to do that since the power pack will have to
be
> powered for anything to work. I was thinking it would be good to shut off
the
> strobes in fog/clouds but still leave the red beacon going. Is this a good
> idea or just more work then needed?
> Thanks
=======================
Nelson:
>From your explanation all four items are flash tubes for the strobe power
supply. If that is the case then the only proper way to wire them is with one
SPST switch to turn on and off the strobe power supply. either ALL is ON or ALL
is OFF.
You do NOT turn the flash tubes on / off you turn the power supply On & Off.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
Message 17
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Subject: | Re: Noise filter noise |
--> AeroElectric-List message posted by: FLYaDIVE@aol.com
In a message dated 8/25/06 2:26:09 PM Eastern Daylight Time,
james@berkut13.com writes:
> Hi all,
>
> I'm wondering if someone could educate me a little on something I
> encountered while trying to eliminate electrical noise coming from an
> autopilot servo. The story goes like this:
>
> I recently installed a new autopilot servo in my Berkut (all composite).
It
> worked perfectly, but for some reason, the servo makes a loud squealing
> noise in the intercom audio when it's activated.
[Barry] When what is activated, the intercom or the servo?
> I did all the usual
> things - changed ground points, increased grounding, double checked
> shielding on cables, un-bundled wires, ferrite beads on the cables, etc.
> The only thing that really worked was to power the servo from a separate
> battery - indicating electrical propagation, not RF. I spoke with the
> manufacturer, and they did mention that there was a 2.5KHz PWM signal that
> is used to control the servo, and that the "noise" I hear is likely that.
> So, on to trying to isolate the servo from everything else...right.
>
> I first tried (at the manufacturer's request) a pair of capacitors (.1uf
and
> 4700uf) in parallel, grounded off the servo power lead itself. This did
> slightly dampen the noise, but certainly not enough.
[Barry] I gather the 47000uf cap was an electrolytic and the other was a
ceramic disc?
> So, I also went out
> and purchased a common 10-amp car audio power filter - just like those
sold
> by Radio Shack and documented by Bob on his site - 2 caps with a choke
coil
> potted in a case although I can not see the ratings on the caps.
> I placed the filter in an orientation that isolated the power source from
the servo,
> instead of servo from power source as IT was the verified source of the
> noise.
[Barry] I'm not sure what you mean my that statement.
Is the filter mounted as close to the servo as posable, short leads and a
clean ground? That is how it should be installed.
>
> The good news is, that filter eliminated about 99% of the noise - and
that's
> good to go. I have not yet done extensive tests to see if the AP now
> operates properly in flight with the filter in-line (possible I/O errors,
> proper servo feedback, etc)...that's coming soon. But, I want to explore
> the "weirdness" first.
>
> Now, the weird (to me anyway) part is that the filter itself now audibly
> "sings" with the same frequency that I had heard before on the intercom.
I
> mean, it literally makes the noise like a speaker would. Is this normal?
[Barry] Weird to me too? Are you saying that the filter has a noise coming
from it? If so then your GROUND is poor and maybe your leads too long. This
of course is assuming that the filter is made well and the coils of the filter
are mounted / potted securely. But, the first thing I would check is the
GROUND.
Other thing to check would be your crimps. I would rather have you tell me
that you soldered these connection.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
Message 18
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Subject: | Re: flap deployment above Vfe |
--> AeroElectric-List message posted by: Jon & Kathryn Hults <legacy@speedband.com>
Military fighter pilots have had much more "consequential" switches on their
throttles and sticks for quite some time. The theory behind HOTAS (Hands On
Throttle And Stick) is that you are less likely to make flight path
deviations if you keep your hands on the controls...and less likely to run
into something if you don't have to look inside to throw a switch. Makes
sense to me.
The trick is in the design of the stick. The top buttons which should
probably be reserved for "consequential" switches (trim, flaps, speedbrakes,
spoilers, etc..) are out of reach with a normal grasp on the stick. A
conscious movement of the thumb is required to activate these switches. You
do have to learn where the switches are and not to touch them when you don't
want them to move. We all learned that way back in the beginning from our
flight instructors...didn't we?
If you want to be sure you can't activate the flaps in cruise flight, try
this http://www.aircraftextras.com/ It uses a relay board to disable the
flap switch above max flap speed to avoid inadvertent flap extension.
I think HOTAS is another great idea that will lead to safer flying in all of
general aviation thanks to experimental builders like us.
My opinion, for what it's worth.
Jon Hults
Message 19
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Subject: | Re: Noise filter noise |
--> AeroElectric-List message posted by: Brian Lloyd <brian-av@lloyd.com>
On Aug 25, 2006, at 11:17 AM, James Redmon wrote:
> Now, the weird (to me anyway) part is that the filter itself now
> audibly "sings" with the same frequency that I had heard before on
> the intercom. I mean, it literally makes the noise like a speaker
> would. Is this normal? What would be causing that? Is this
> symptomatic of some additional problem that might effect servo
> operation? Something else I should do or try?
You are putting current pulses through an inductor so it has a
magnetic field that is varying with the current pulses. Any steel
object nearby is going to be alternately pulled and released by the
varying magnetic field. It is probably the case of the inductor or
the inductor's core that is making the noise.
OTOH, there shouldn't be that much current change. Put the capacitor
combo back at the input to the servo.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
Message 20
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Subject: | Re: Problems with High EGT readings |
--> AeroElectric-List message posted by: Brian Lloyd <brian-av@lloyd.com>
On Aug 25, 2006, at 1:52 PM, Ron Patterson wrote:
> Hey all,
> I've just begun to have 1450+ EGT readings on all cylinders, while
> the CHT's remain below 390 degrees. No attempt to richen things up
> (carb heat for example) improves things. I took off the cowl and
> see no exterior signs of trouble, removed spark plugs and they are
> nice and tan and even wet from running too rich. I tried a brief
> flight and all was normal, then on the next long leg they did it
> again. I recycled the Grand Rapids EIS and then only one cylinder
> persisted in giving me this reading. Am I right to assume it is an
> indicator/gauge issue or am I missing something more ominous?
If you have a sudden high EGT on all cylinders, check to see if one
mag has stopped working. If both mags are normal and CHTs are normal,
look for a gauge problem.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
Message 21
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Subject: | Re: Noise filter noise |
--> AeroElectric-List message posted by: Dave N6030X <N6030X@DaveMorris.com>
Well, 2.5 KHz is within the audible frequency range. The A above
Middle C is 440 Hz. So you're only talking about less than 6 octaves
above it. All it would take is having the coil inside the filter
that has this frequency applied to it being physically in contact
with the case or other structure. I can envision that real
easily. We usually call that "headphones" or "loud speaker". So,
you might have to take it apart and make sure the filter is
physically isolated from the box around it using RTV or rubber
gaskets or something.
Be careful about filtering the PWM signal, though. The whole purpose
is to feed that signal to the servo, and if you are applying a filter
that changes the shape, the servo might start functioning incorrectly.
Dave Morris
At 01:17 PM 8/25/2006, you wrote:
>--> AeroElectric-List message posted by: "James Redmon" <james@berkut13.com>
>
>Hi all,
>
>I'm wondering if someone could educate me a little on something I
>encountered while trying to eliminate electrical noise coming from
>an autopilot servo. The story goes like this:
>
>I recently installed a new autopilot servo in my Berkut (all
>composite). It worked perfectly, but for some reason, the servo
>makes a loud squealing noise in the intercom audio when it's
>activated. I did all the usual things - changed ground points,
>increased grounding, double checked shielding on cables, un-bundled
>wires, ferrite beads on the cables, etc. The only thing that really
>worked was to power the servo from a separate battery - indicating
>electrical propagation, not RF. I spoke with the manufacturer, and
>they did mention that there was a 2.5KHz PWM signal that is used to
>control the servo, and that the "noise" I hear is likely that. So,
>on to trying to isolate the servo from everything else...right.
>
>I first tried (at the manufacturer's request) a pair of capacitors
>(.1uf and 4700uf) in parallel, grounded off the servo power lead
>itself. This did slightly dampen the noise, but certainly not
>enough. So, I also went out and purchased a common 10-amp car audio
>power filter - just like those sold by Radio Shack and documented by
>Bob on his site - 2 caps with a choke coil potted in a case although
>I can not see the ratings on the caps. I placed the filter in an
>orientation that isolated the power source from the servo, instead
>of servo from power source as IT was the verified source of the noise.
>
>The good news is, that filter eliminated about 99% of the noise -
>and that's good to go. I have not yet done extensive tests to see
>if the AP now operates properly in flight with the filter in-line
>(possible I/O errors, proper servo feedback, etc)...that's coming
>soon. But, I want to explore the "weirdness" first.
>
>Now, the weird (to me anyway) part is that the filter itself now
>audibly "sings" with the same frequency that I had heard before on
>the intercom. I mean, it literally makes the noise like a speaker
>would. Is this normal? What would be causing that? Is this
>symptomatic of some additional problem that might effect servo
>operation? Something else I should do or try?
>
>All information and education is welcome...but remember, I'm not an EE. ;-)
>
>Eager to learn,
>
>James Redmon
>Berkut #013 N97TX
>http://www.berkut13.com
>
>
>By the way, this is not a common situation as the manufacturer has
>not seen this type of issue before...although they are doing
>everything they can to get this under control - under warranty, to
>their credit! I have no issues with the way they are handling
>this..so please don't pester me about that part.
>
>
Message 22
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Subject: | Re: Problems with High EGT readings |
--> AeroElectric-List message posted by: FLYaDIVE@aol.com
In a message dated 8/25/06 8:41:24 PM Eastern Daylight Time,
brian-av@lloyd.com writes:
> If you have a sudden high EGT on all cylinders, check to see if one
> mag has stopped working. If both mags are normal and CHTs are normal,
> look for a gauge problem.
================================
Brian:
If you reduce your spark in half your EGT goes DOWN not UP. Loss of a Mag
reduces combustion efficiency. If the timing is incorrect EGT can go UP but
usually the Oil and CHT follows.
Ron said CHT was 390 F but he did not say that was his NORMAL ... Only that
is below 390F.
What Ron should be looking for is something that will cause LEANING ...
either Less Fuel or More Air.
My first place to look would be an AIR LEAK around the Carb.
Second place would be the rubber coupling on the intake, but the chances of
that are very slim since ALL cylinder increased EGT.
Third place is an EXHAUST Leak. Around the flanges ... Ron, you didn't use
those cheep soft exhaust gaskets?
I have a very difficult time believing that all 4 EGT probes drifted in the
same direction. Or that the EIS failed in such a manor that ONLY the EGT was
affected and not the CHT.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
Message 23
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Subject: | Re: Problems with High EGT readings |
X-mailer: Pegasus Mail for Windows (4.21c)
--> AeroElectric-List message posted by: "Jim Baker" <jlbaker@msbit.net>
> If you reduce your spark in half your EGT goes DOWN not UP.
Loss of a
> Mag reduces combustion efficiency.
Nope. EGT should rise about 50 degrees F on all cylinders. Think a
bit more about this and you'll understand why it work this way....
Jim Baker
580.788.2779
'71 SV, 492TC
Elmore City, OK
Message 24
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Subject: | Re: Problems with High EGT readings |
On Aug 25, 2006, at 3:52 PM, Ron Patterson wrote:
> Hey all,
> I've just begun to have 1450+ EGT readings on all cylinders, while
> the CHT's remain below 390 degrees. No attempt to richen things up
> (carb heat for example) improves things. I took off the cowl and
> see no exterior signs of trouble, removed spark plugs and they are
> nice and tan and even wet from running too rich. I tried a brief
> flight and all was normal, then on the next long leg they did it
> again. I recycled the Grand Rapids EIS and then only one cylinder
> persisted in giving me this reading. Am I right to assume it is an
> indicator/gauge issue or am I missing something more ominous?
> Thanks in advance for your ideas.
> Ron
> RV-4 N8ZD
Hi Ron
As Brian mentioned, loss of one ignition will cause all the EGTs to
rise simultaneously, along with a small loss of power and slightly
lower CHTs. I have had these exact symptoms caused by an ignition
failure in the climb--I noticed it when EGTs went well above their
normal peaks as I tried to lean. You can diagnose this quickly by
cycling the mags in the air, but this is probably best done without
your wife in the back seat (or so I've heard. At length.).
I think it's most likely an indicator issue, but would check ignition
first. I have a vague recollection of reading about similar symptoms
with an EIS with a wiring issue sometime in the last few weeks. You
might want to try Greg at Grand Rapids--he seems to be pretty
responsive. A search of the various RV/aerolelectric forums and
Doug's VAF site for "EIS" and "EGT" might turn up some relevant posts.
James Freeman
Message 25
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Subject: | Re: Problems with High EGT readings |
--> AeroElectric-List message posted by: Kelly McMullen <kellym@aviating.com>
Sorry Barry, but Brian is correct. Demonstrable on any mag check during
run up or an in flight mag check. The flame front propagates slower with
single ignition, and burns longer in the cylinder, making it hotter
coming out the exhaust.
FLYaDIVE@aol.com wrote:
> --> AeroElectric-List message posted by: FLYaDIVE@aol.com
>
> In a message dated 8/25/06 8:41:24 PM Eastern Daylight Time,
> brian-av@lloyd.com writes:
>
>> If you have a sudden high EGT on all cylinders, check to see if one
>> mag has stopped working. If both mags are normal and CHTs are normal,
>> look for a gauge problem.
> ================================
> Brian:
>
> If you reduce your spark in half your EGT goes DOWN not UP. Loss of a Mag
> reduces combustion efficiency. If the timing is incorrect EGT can go UP but
> usually the Oil and CHT follows.
> Ron said CHT was 390 F but he did not say that was his NORMAL ... Only that
> is below 390F.
Message 26
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Subject: | Re: Problems with High EGT readings |
--> AeroElectric-List message posted by: OldBob Siegfried <oldbob@beechowners.com>
Good Evening Barry,
May I suggest that you rethink that a bit?
When operating on one magneto, the EGTs will rise.
Why?
Because the timing is effectively retarded and the
peak temperature occurs later in the combustion cycle.
The fire gets closer to the point where it is
measured. The actual peak combustion pressure and
temperature will both be lower, but due to the timing
change, the EGTs Will be higher.
Happy Skies,
Old Bob
--- FLYaDIVE@aol.com wrote:
> --> AeroElectric-List message posted by:
> FLYaDIVE@aol.com
>
> In a message dated 8/25/06 8:41:24 PM Eastern
> Daylight Time,
> brian-av@lloyd.com writes:
>
> > If you have a sudden high EGT on all cylinders,
> check to see if one
> > mag has stopped working. If both mags are normal
> and CHTs are normal,
> > look for a gauge problem.
> ================================
> Brian:
>
> If you reduce your spark in half your EGT goes DOWN
> not UP. Loss of a Mag
> reduces combustion efficiency. If the timing is
> incorrect EGT can go UP but
> usually the Oil and CHT follows.
> Ron said CHT was 390 F but he did not say that was
> his NORMAL ... Only that
> is below 390F.
>
> What Ron should be looking for is something that
> will cause LEANING ...
> either Less Fuel or More Air.
> My first place to look would be an AIR LEAK around
> the Carb.
> Second place would be the rubber coupling on the
> intake, but the chances of
> that are very slim since ALL cylinder increased EGT.
>
> Third place is an EXHAUST Leak. Around the flanges
> ... Ron, you didn't use
> those cheep soft exhaust gaskets?
> I have a very difficult time believing that all 4
> EGT probes drifted in the
> same direction. Or that the EIS failed in such a
> manor that ONLY the EGT was
> affected and not the CHT.
>
> Barry
> "Chop'd Liver"
>
> "Show them the first time, correct them the second
> time, kick them the third
> time."
> Yamashiada
>
>
> browse
> Subscriptions page,
> FAQ,
> http://www.matronics.com/Navigator?AeroElectric-List
>
> Web Forums!
>
>
> Admin.
>
>
>
>
>
Message 27
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Subject: | Re: Problems with High EGT readings |
--> AeroElectric-List message posted by: "John D.Heath" <altoq@cebridge.net>
Barry,
I always get in trouble when I do this but, here goes. By eliminating one
of two firing positions, You effectively retard timing because Peak BMEP
occurs later. Combustion is incomplete, some of what does not burn in the
chamber, burns in the exhaust pipes, hence, higher EGT. CHT may or may not
be lower (depends on too many other things). I would initially look for a
primary ignition fault.
John D.
DO NOT ARCHIVE
> Brian:
>
> If you reduce your spark in half your EGT goes DOWN not UP. Loss of a Mag
> reduces combustion efficiency. If the timing is incorrect EGT can go UP
> but
> usually the Oil and CHT follows.
> Ron said CHT was 390 F but he did not say that was his NORMAL ... Only
> that
> is below 390F.
>
> What Ron should be looking for is something that will cause LEANING ...
> either Less Fuel or More Air.
> My first place to look would be an AIR LEAK around the Carb.
> Second place would be the rubber coupling on the intake, but the chances
> of
> that are very slim since ALL cylinder increased EGT.
> Third place is an EXHAUST Leak. Around the flanges ... Ron, you didn't
> use
> those cheep soft exhaust gaskets?
> I have a very difficult time believing that all 4 EGT probes drifted in
> the
> same direction. Or that the EIS failed in such a manor that ONLY the EGT
> was
> affected and not the CHT.
>
> Barry
> "Chop'd Liver"
Message 28
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Subject: | Re: Problems with High EGT readings |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Turning off one mag slows down the combustion process - effectively
retarding the spark timing. That will cause the EGT to rise because more
of the fuel air mixture will be left burning when the exhaust valve opens.
Cylinder pressure WILL be lower..
See John Deak and George Braly for more info. Or.. Try it on your plane.
Regards,
Matt-
FLYaDIVE@aol.com wrote:
>--> AeroElectric-List message posted by: FLYaDIVE@aol.com
>
>In a message dated 8/25/06 8:41:24 PM Eastern Daylight Time,
>brian-av@lloyd.com writes:
>
>>If you have a sudden high EGT on all cylinders, check to see if one
>> mag has stopped working. If both mags are normal and CHTs are normal,
>> look for a gauge problem.
>
>================================
>Brian:
>
>If you reduce your spark in half your EGT goes DOWN not UP. Loss of a Mag
>reduces combustion efficiency. If the timing is incorrect EGT can go UP but
>usually the Oil and CHT follows.
>Ron said CHT was 390 F but he did not say that was his NORMAL ... Only that
>is below 390F.
>
>What Ron should be looking for is something that will cause LEANING ...
>either Less Fuel or More Air.
>My first place to look would be an AIR LEAK around the Carb.
>Second place would be the rubber coupling on the intake, but the chances of
>that are very slim since ALL cylinder increased EGT.
>Third place is an EXHAUST Leak. Around the flanges ... Ron, you didn't use
>those cheep soft exhaust gaskets?
>I have a very difficult time believing that all 4 EGT probes drifted in the
>same direction. Or that the EIS failed in such a manor that ONLY the EGT
was
>affected and not the CHT.
>
>Barry
>"Chop'd Liver"
>
>"Show them the first time, correct them the second time, kick them the third
>time."
>Yamashiada
>
Message 29
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Subject: | Re: Problems with High EGT readings |
--> AeroElectric-List message posted by: Brian Lloyd <brian-av@lloyd.com>
On Aug 25, 2006, at 6:59 PM, FLYaDIVE@aol.com wrote:
> --> AeroElectric-List message posted by: FLYaDIVE@aol.com
>
> In a message dated 8/25/06 8:41:24 PM Eastern Daylight Time,
> brian-av@lloyd.com writes:
>
>> If you have a sudden high EGT on all cylinders, check to see if one
>> mag has stopped working. If both mags are normal and CHTs are
>> normal,
>> look for a gauge problem.
> ================================
> Brian:
>
> If you reduce your spark in half your EGT goes DOWN not UP.
Normally I try to be diplomatic but in this case I will make an
exception. You are just plain wrong.
Proof:
Turn off one mag in cruise and watch your EGT go up by about 100F.
Reason:
With both mags working you have two flame-fronts in the combustion
chamber. This means that combustion completes sooner allowing more
time for the gas to transfer heat to the components in the cylinder
thus leading to cooler gas going out the exhaust. When you turn off
one mag you have only one flame front and the combustion time is
slightly longer. There is now less time after the end of combustion
and before the exhaust valve opens so your EGT is higher.
> Loss of a Mag reduces combustion efficiency.
Yeah, so?
> If the timing is incorrect EGT can go UP but
> usually the Oil and CHT follows.
Actually, if you get advanced timing your CHT will go up but your EGT
will go down for the reasons I outlined above. Detonation will do the
same thing.
> Ron said CHT was 390 F but he did not say that was his NORMAL ...
> Only that
> is below 390F.
I read that to mean that he did not see an increase in CHT.
>
> What Ron should be looking for is something that will cause
> LEANING ...
Perhaps. The simplest explanation for a 100F rise in EGT across all
cylinders without a rise in CHT is the loss of a mag. (Actually CHT
will drop slightly as less heat is transferred to the head.) It is
also pitifully easy to check. After that it is time for more
difficult tests and inspections.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
Message 30
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Subject: | Re: Noise filter noise |
--> AeroElectric-List message posted by: "James Redmon" <james@berkut13.com>
>> I recently installed a new autopilot servo in my Berkut (all composite).
> It
>> worked perfectly, but for some reason, the servo makes a loud squealing
>> noise in the intercom audio when it's activated.
>
> [Barry] When what is activated, the intercom or the servo?
When the servo is active. The squeal is itermittent but coupled with the
motion of the servo. As in when pressure is applied against the stick and
the servo is commanded to move the other direction. This was without the
filter installed, of course.
>> I did all the usual
>> things - changed ground points, increased grounding, double checked
>> shielding on cables, un-bundled wires, ferrite beads on the cables, etc.
>> The only thing that really worked was to power the servo from a separate
>> battery - indicating electrical propagation, not RF. I spoke with the
>> manufacturer, and they did mention that there was a 2.5KHz PWM signal
>> that
>> is used to control the servo, and that the "noise" I hear is likely
>> that.
>> So, on to trying to isolate the servo from everything else...right.
>>
>> I first tried (at the manufacturer's request) a pair of capacitors (.1uf
> and
>> 4700uf) in parallel, grounded off the servo power lead itself. This did
>> slightly dampen the noise, but certainly not enough.
>
> [Barry] I gather the 47000uf cap was an electrolytic and the other was a
> ceramic disc?
Yup. The cap combo didn't do much to squelch the noise. The filter cuts it
by 99%.
>> So, I also went out
>> and purchased a common 10-amp car audio power filter - just like those
> sold
>> by Radio Shack and documented by Bob on his site - 2 caps with a choke
> coil
>> potted in a case although I can not see the ratings on the caps.
>
>> I placed the filter in an orientation that isolated the power source from
> the servo,
>> instead of servo from power source as IT was the verified source of the
>> noise.
>
> [Barry] I'm not sure what you mean my that statement.
> Is the filter mounted as close to the servo as posable, short leads and a
> clean ground? That is how it should be installed.
Yes, they are short - about 3" from servo. I rigged up a short pig-tail so
I could attach it and detach it for testing. I just mean that the filter
is a stimple choke coil with a two caps in parallel like Bob has documented:
http://www.aeroelectric.com/articles/filter/RS_Noise_Filters.pdf#search=%22filter%22
>> The good news is, that filter eliminated about 99% of the noise - and
> that's
>> good to go. I have not yet done extensive tests to see if the AP now
>> operates properly in flight with the filter in-line (possible I/O
>> errors,
>> proper servo feedback, etc)...that's coming soon. But, I want to
>> explore
>> the "weirdness" first.
>>
>> Now, the weird (to me anyway) part is that the filter itself now audibly
>> "sings" with the same frequency that I had heard before on the intercom.
> I
>> mean, it literally makes the noise like a speaker would. Is this
>> normal?
>
> [Barry] Weird to me too? Are you saying that the filter has a noise
> coming
> from it? If so then your GROUND is poor and maybe your leads too long.
> This
> of course is assuming that the filter is made well and the coils of the
> filter
> are mounted / potted securely. But, the first thing I would check is the
> GROUND.
Yup. the filter itself is the source of the audible noise. It is connected
to the common "nose" ground block. That block is fat wired striaght back to
the battery. I'm not sure what else to "check" or how. I have opened the
filter's case up, but it's components are potted with glue and I can't read
the cap values. But I can see that it's just a coil, and two caps in a
plastic case.
> Other thing to check would be your crimps. I would rather have you tell
> me
> that you soldered these connection.
All PIDG crimps. All have been checked as secure.
Filter still singing like a canary.
James Redmon
Berkut #013 N97TX
http://www.berkut13.com
Message 31
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Subject: | Re: Noise filter noise |
--> AeroElectric-List message posted by: "James Redmon" <james@berkut13.com>
> You are putting current pulses through an inductor so it has a magnetic
> field that is varying with the current pulses. Any steel object nearby is
> going to be alternately pulled and released by the varying magnetic
> field. It is probably the case of the inductor or the inductor's core
> that is making the noise.
Humm...might be the inductor core..it's not mounted near anything else (6"+
minimum). The noise is definately coming from inside the filter case
(plastic) and I can feel it vibrating with the sound.
> OTOH, there shouldn't be that much current change. Put the capacitor
> combo back at the input to the servo.
The cap combo didn't do much at all to help the noise. Maybe a 5%
reduction.
Thanks for the input!
James Redmon
Berkut #013 N97TX
http://www.berkut13.com
Message 32
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Subject: | Re: Noise filter noise |
--> AeroElectric-List message posted by: "James Redmon" <james@berkut13.com>
> Well, 2.5 KHz is within the audible frequency range. The A above Middle C
> is 440 Hz. So you're only talking about less than 6 octaves above it.
> All it would take is having the coil inside the filter that has this
> frequency applied to it being physically in contact with the case or other
> structure. I can envision that real easily. We usually call that
> "headphones" or "loud speaker". So, you might have to take it apart and
> make sure the filter is physically isolated from the box around it using
> RTV or rubber gaskets or something.
Well, the caps and coil are in a plastic case, and are installed with some
kind of clear gel glue - like hot glue. I can not see that anything is
touching the case without the goop inbetween.
> Be careful about filtering the PWM signal, though. The whole purpose is
> to feed that signal to the servo, and if you are applying a filter that
> changes the shape, the servo might start functioning incorrectly.
Yeah. There does not seem to be any issues with the servo operation, but
then I have not flown it either. I will do some flight testing tomorrow.
I also plan to disconnect the filter, setup the AP servo, get it working in
flight (if I can bear the noise in the headset), and then re-connect the
filter and see if there are any servo problems.
I'll know more tomorrow. One thing - I can live with the singing filter if
the AP works properly. It's not loud enough to hear over any engine
noise....but the noise over the headsets is LOUD!
James Redmon
Berkut #013 N97TX
http://www.berkut13.com
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