Today's Message Index:
----------------------
1. 12:22 AM - Re: AeroElectric-List Digest: 6 Msgs - 06/12/12 (Franz Fux)
2. 05:48 AM - Re: Pitot Tube Help (Eric M. Jones)
3. 06:07 AM - Re: Re: AeroElectric-List Digest: 6 Msgs - 06/12/12 (Michael Welch)
4. 06:34 AM - Re: Re: Pitot Tube Help (BobsV35B@aol.com)
5. 07:23 AM - Re: Re: Pitot Tube Help (Dj Merrill)
6. 08:05 AM - Re: Re: AeroElectric-List Digest: 6 Msgs - 06/12/12 (Bob McCallum)
7. 08:35 AM - Withdrawal from the list (Float Flyr)
8. 08:53 AM - Re: Withdrawal from the list (Robert Borger)
9. 09:22 AM - Re: Pitot Tube Help (Jeff Luckey)
10. 10:12 AM - SL-40 (Dan Billingsley)
11. 10:15 AM - Inexpensive CAD Software (Jeff Luckey)
12. 10:51 AM - Re: Inexpensive CAD Software (GERRY VAN%20DYK)
13. 11:09 AM - Re: Inexpensive CAD Software (ROGER & JEAN CURTIS)
14. 11:17 AM - Re: SL-40 (Bill Schlatterer)
15. 11:33 AM - Re: Pitot Tube Help (Robert L. Nuckolls, III)
16. 11:33 AM - Re: SL-40 (Dan Billingsley)
17. 11:36 AM - Re: Inexpensive CAD Software (Robert L. Nuckolls, III)
18. 11:51 AM - Re: SL-40 (B Tomm)
19. 12:09 PM - Re: SL-40 (Dan Billingsley)
20. 02:45 PM - Re: SL-40 (John Morgensen)
21. 05:18 PM - Re: SL-40 (Charlie England)
22. 05:24 PM - Re: SL-40 (Dan Billingsley)
23. 05:52 PM - Re: SL-40 (Dan Billingsley)
24. 06:22 PM - Re: SL-40 (Bob McCallum)
25. 06:28 PM - Re: SL-40 (Charlie England)
26. 06:52 PM - Re: SL-40 (Bill Bradburry)
27. 06:58 PM - Re: SL-40 (Jared Yates)
28. 07:06 PM - Re: Inexpensive CAD Software (Rick Lark)
29. 07:25 PM - Re: SL-40 (Dan Billingsley)
Message 1
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| Subject: | Re: AeroElectric-List Digest: 6 Msgs - 06/12/12 |
only intermittent access to e-mail until June 19th, in an urgent matter contact
info@lastfrontierheli.com
Message 2
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| Subject: | Re: Pitot Tube Help |
My 2 cents:
I have kept the attached drawing of a pitot tube around to remind me that there
are lots of ways to go, and lots that is known that I don't know.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=375506#375506
Attachments:
http://forums.matronics.com//files/pitotc46_198.pdf
Message 3
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| Subject: | Re: AeroElectric-List Digest: 6 Msgs - 06/12/12 |
Can someone remove this maggot spammer?
On Jun 13, 2012, at 2:20 AM, Franz Fux wrote:
<franz@lastfrontierheli.com>
>
> only intermittent access to e-mail until June 19th, in an urgent
matter contact
> info@lastfrontierheli.com
Message 4
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| Subject: | Re: Pitot Tube Help |
Good Morning Eric,
Sure looks busy!
Happy skies,
Old Bob
In a message dated 6/13/2012 7:49:00 A.M. Central Daylight Time,
emjones@charter.net writes:
--> AeroElectric-List message posted by: "Eric M. Jones"
<emjones@charter.net>
My 2 cents:
I have kept the attached drawing of a pitot tube around to remind me that
there are lots of ways to go, and lots that is known that I don't know.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=375506#375506
Attachments:
http://forums.matronics.com//files/pitotc46_198.pdf
Message 5
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| Subject: | Re: Pitot Tube Help |
On 6/13/2012 9:32 AM, BobsV35B@aol.com wrote:
> Sure looks busy!
>
Yeah, I'm having pitot envy. The pitot tube on my plane is
literally just an aluminum tube bent into the wind... :-)
-Dj
Message 6
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| Subject: | Re: AeroElectric-List Digest: 6 Msgs - 06/12/12 |
Michael=3B
Manners??
It's unlikely he's a "spammer". He is probably a sunscriber to the digest v
ersion of the list who is away and has set his e-mail to "auto-reply" to in
dicate his current inability to read e-mails. Each day that he receives the
digest his e-mail client auto replys to that effect. Until he returns to a
ctive monitoring we'll see one reply a day each time he is sent his daily e
-mail by Matronics.. Not really a big deal. Just hit delete.
Bob McC
Subject: Re: AeroElectric-List: Re: AeroElectric-List Digest: 6 Msgs - 06/1
2/12
From: mdnanwelch7@hotmail.com
Can someone remove this maggot spammer?
On Jun 13=2C 2012=2C at 2:20 AM=2C Franz Fux wrote:--> AeroElectric-List me
ssage posted by: "Franz Fux" <franz@lastfrontierheli.com>
only intermittent access to e-mail until June 19th=2C in an urgent matter
contact
info@lastfrontierheli.com
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
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3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
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3D
Message 7
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| Subject: | Withdrawal from the list |
About two weeks ago I had a major fire here. Caused by, so they say, a faulty
extension cord. For the time of being I am going to withdraw from all my aviation
lists. I hope you all continue to post and fly safely.
Clear skies
Noel
--------
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=375533#375533
Message 8
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| Subject: | Re: Withdrawal from the list |
Noel,
Sorry to hear about your fire. Good luck getting things back together. I hope
you are able to return to aviation soon.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop.
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger@mac.com
On Jun 13, 2012, at 10:33 AM, Float Flyr wrote:
About two weeks ago I had a major fire here. Caused by, so they say, a faulty
extension cord. For the time of being I am going to withdraw from all my aviation
lists. I hope you all continue to post and fly safely.
Clear skies
Noel
--------
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats
Message 9
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Bingo! Almost everything you wanted to know about pitot tubes (but were
afraid to ask). I wanted to know what the guts looked like & Bob provides a
picture before I can ask!
Aint this list great! Thanks to BobN and all who replied.
One data point for those who care: I connected the heater to a 12V power
supply and found that after about a minute the current was about 2.5 amps @
12.8 volts and the tube was hot enough to sizzle spit, literally. The tube
is rated for 24V.
-Jeff
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Tuesday, June 12, 2012 14:25
Subject: RE: AeroElectric-List: Pitot Tube Help
From: Jeff Luckey
Sent: Tuesday, June 12, 2012 10:46 AM
Subject: AeroElectric-List: Pitot Tube Help
Off topic! (well it is electrically heated;) Looking to capitalize on the
Aerolectric Brain Trust to find an old pitot tube expert.
I have a pitot tube, Aero Instrument PH504, (AN 5811-1), which is looks like
a typical C-172 pitot tube (you know, "L" shaped with about a 4 in tube
attached to an airfoil cross-section vertical piece. When mounted under the
wing on a C-172 the tube part would be closest to the ground.)
However this one is designed for INVERTED mounting, apparently designed to
be mounted to a top surface of an airframe (where the tube part would be
furthest from the ground.)
I'm pretty sure that the air doesn't care which way the thing is mounted, as
long as the tube is parallel to the air stream. So my guess is that the
Inverted model has drain holes in different places.
Questions:
does drain hole position REALLY matter?
* Multiple Choice: What will happen in flight if this device is
mounted the standard way (not inverted) and it picks-up a little moisture?
* water in pitot lines
* inaccurate airspeed indication
* the end of life as we know it
* smoking crater
A modern pitot tube is a complex study in aerodynamics,
pneumatics, thermal dynamics and manufacturing. Contemporary
design goals for a 'qualified' pitot tube calls for testing
in an icing tunnel that is supposed to be sort of a worst case
icing condition.
http://tinyurl.com/7pmnqta
Emacs!
The idea is to melt any ice accumulation and provide a place
for the moisture to go besides into the pitot-static plumbing.
At the same time, many airplanes are fitted with accumulators
at the system's low-spot that include a drain for removing
any water.
Some years ago at HBC, we had a series of incidents involving
loss of pitot data on both sides at the same time at altitude
with no visible moisture (clouds or ice crystals). Both systems
recovered before the airplane landed and draining the accumulators
produced no observable moisture.
The pitot tubes installed were grand-fathered over from earlier
installations and not 'qualified' to the latest and greatest
de-icing specs. In fact, the tubes were originally installed
pointed up at about 45 degree angle and had been moved to the
bottom pointed downward thus placing the drain hole in the
wrong clocking.
New, latest and greatest tubes were installed. I'm not aware
of any recurring incidents . . . need to make some phone calls.
I'm a bit skeptical. I did some flight tests on the original
tubes to measure internal and temperatures. The areas all over
the tube remained well above freezing (LT1, LT3, LT4 curves
in http://tinyurl.com/74yr5q8 <http://tinyurl.com/74yr5q8%A0%A0> )
The idea that there was frozen blockage of passages inside the
tube didn't compute. So even if water did run down into the
plumbing, where did it come from? Thawed ice crystals? Your
guess is as good as mine. In any case, position of the drain
hole was certainly not a high order concern.
What I did come to understand was that unless your heated pitot
tube is mounted to a machine qualified for flight into known
icing, the ability to heat the tube is of limited usefulness.
Once the tube is overwhelmed the flight characteristics (airfoil
shapes) combined with added weight of ice make sort of pollutes
the value of knowing indicated airspeed. The recommended process
being to get to warmer altitudes without without changing anything
that would move you closer to the low-speed corner of a flight
envelope that is no longer defined.
What you have is probably a fine device for use outside of
icing conditions. Inside icing conditions becomes a toss-up
as to whether the flight qualities airplane or the instrumentation
get overwhelmed first.
Wire that heater up if it makes you feel any better but
know that having good IAS numbers is only part of the equation.
Got a real good lesson during my only in-flight instrument
approach in icing conditions. In this case, my instructor
was sitting there calmly waiting for me to figure it out all
the way down to the flare after having kept all the needles
centered up for over 15 minutes in the clouds.
The airplane fell out of the air and muffed what was
supposed to be a good "by the numbers" landing . . . numbers
that no longer represented the shape of the wing. Bottom
line is that ice presents worries that can be a lot more
hazardous than IAS numbers.
Bob . . .
No virus found in this message.
Checked by AVG - www.avg.com
Message 10
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Just when I thought I was out of the woods, an ole nemesis returns. As I me
ntioned in the last post, my noise going into intercom was canceled by an i
n-line audio suppressor.=0ARight after I did a run-up today getting ready t
o take off, I taxied to the hold-short line and called the tower. I lost my
radio. I got back to the hanger to find for the second time I blew the 5 A
fuse. The last time this happened was 11 to 12 hours ago. The SL-40 is wir
ed to the E-Bus. I am of course concerned as to why this is happening, but
know it could be a tough one to nail down. My thoughts have led me to try r
unning power from the main bus but also using a DPDT switch to be able to f
lip the power to the radio via the-=0AE-bus should it go south again. Any
other ideas are welcome.=0ADan B
Message 11
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| Subject: | Inexpensive CAD Software |
Several months ago, I think I saw some traffic on this list about
inexpensive CAD software.
All I really need is some simple line-drawing & dimensioning capabilities to
layout a panel.
I used to use TurboCAD (~5-7 years ago). What's the hot ticket today?
-Jeff
Message 12
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| Subject: | Re: Inexpensive CAD Software |
Perhaps overkill, but Draftsight might be the ticket for you.
http://www.3ds.com/products/draftsight/overview/
Gerry
----- Original Message -----
From: "Jeff Luckey" <JLuckey@pacbell.net>
Sent: Wednesday, June 13, 2012 11:14:01 AM
Subject: AeroElectric-List: Inexpensive CAD Software
Several months ago, I think I saw some traffic on this list about inexpensive CAD
software.
All I really need is some simple line-drawing & dimensioning capabilities to layout
a panel.
I used to use TurboCAD (~5-7 years ago). Whats the hot ticket today?
-Jeff
Message 13
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| Subject: | Inexpensive CAD Software |
Several months ago, I think I saw some traffic on this list about
inexpensive CAD software.
All I really need is some simple line-drawing & dimensioning
capabilities to
layout a panel.
I used to use TurboCAD (~5-7 years ago). What's the hot ticket today?
-Jeff
I have been using TurboCad with good results. It's
available for cheap on Ebay. DoubleCad is free on the
internet, but I have no experience with it. Believe
it is from the same company that does TurboCad.
Roger
Message 14
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Dan just curious, when you say lost . does that mean no power at all or no
transmit/receive power? Maybe only on the 430 but it seems like there are
two fuses. My SL40 just quit passing any audio to the headphones but still
appears to indicate RX/TX as if power is applied and it is working.
Bill S
RV7a
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dan
Billingsley
Sent: Wednesday, June 13, 2012 12:09 PM
Subject: AeroElectric-List: SL-40
Just when I thought I was out of the woods, an ole nemesis returns. As I
mentioned in the last post, my noise going into intercom was canceled by an
in-line audio suppressor.
Right after I did a run-up today getting ready to take off, I taxied to the
hold-short line and called the tower. I lost my radio. I got back to the
hanger to find for the second time I blew the 5 A fuse. The last time this
happened was 11 to 12 hours ago. The SL-40 is wired to the E-Bus. I am of
course concerned as to why this is happening, but know it could be a tough
one to nail down. My thoughts have led me to try running power from the main
bus but also using a DPDT switch to be able to flip the power to the radio
via the
E-bus should it go south again. Any other ideas are welcome.
Dan B
Message 15
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One data point for those who care: I connected the heater to a 12V
power supply and found that after about a minute the current was
about 2.5 amps @ 12.8 volts and the tube was hot enough to sizzle
spit, literally. The tube is rated for 24V.
Which brings up another set of design goals for
heated pitot installation. How much energy and
under what conditions are needed for perfomance
to design goals. While doing those studies for
HBC I crafted this paper on heater temperature
coefficient of resistance and thermal resistance
from heater to tube.
http://tinyurl.com/7778mm5
When operated in insulated, still air, the 13v pitot
tube temperature rose to over 100C with less than
2 volts applied power. When operated at rated voltage
in a stirred ice bath, the surface of the tube was
of course at 0C but the internal heater was running
at about 270 degrees C.
Modern tubes don't have so large a differential. Another
important revelation was the cold start resistance of the
pitot tube. Just coming up from 0C, the tube wanted
30+ amps of inrush that persisted quite awhile. It took
about 30 seconds for the current to stabilize at the
expected 16 amps of steady state draw.
During one set of flight tests, we installed thermocouples
http://tinyurl.com/6o5hpdk
and produced this data set
http://tinyurl.com/7ougkfu
Note that at 40K feet, -50C OAT and IAS about 200 kts,
the hot spot on the tube (Ta) was 100C or better. That
cold air blasting the tube at high velocity doesn't have
very good cooling qualities at such low ambient pressures.
Bob . . .
Message 16
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Bill, yes, no power at all. The radio just went dead as it blew the 5A fuse
at the E-bus. I looked up the SL-40 install manual and the unit does have
a 7A internal fuse, but they do recommend the power in to be fused / breake
r'd at no greater than 5A. It does not make much sense to me for this to ha
ppen every 10 to 15 hours.=0ADan=0A=0A=0A________________________________
=0A From: Bill Schlatterer <billschlatterer@sbcglobal.net>=0ATo: aeroelectr
ic-list@matronics.com =0ASent: Wednesday, June 13, 2012 11:15 AM=0ASubject:
RE: AeroElectric-List: SL-40=0A =0A=0ADan just curious, when you say lost
does that mean no power at all or no transmit/receive power?=C2
- Maybe only on the 430 but it seems like there are two fuses.=C2- My S
L40 just quit passing any audio to the headphones but still appears to indi
cate RX/TX as if power is applied and it is working. =0A=C2-=0ABill S=0AR
V7a=0A=C2-=0A=C2-=0A=C2-=0AFrom:owner-aeroelectric-list-server@matron
ics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Dan Billingsley=0ASent: Wednesday, June 13, 2012 12:09 PM=0ATo: aeroelectri
c-list@matronics.com=0ASubject: AeroElectric-List: SL-40=0A=C2-=0AJust wh
en I thought I was out of the woods, an ole nemesis returns. As I mentioned
in the last post, my noise going into intercom was canceled by an in-line
audio suppressor.=0ARight after I did a run-up today getting ready to take
off, I taxied to the hold-short line and called the tower. I lost my radio.
I got back to the hanger to find for the second time I blew the 5 A fuse.
The last time this happened was 11 to 12 hours ago. The SL-40 is wired to t
he E-Bus. I am of course concerned as to why this is happening, but know it
could be a tough one to nail down. My thoughts have led me to try running
power from the main bus but also using a DPDT switch to be able to flip the
power to the radio via the=C2-=0AE-busshould it go south again. Any othe
r ideas are welcome.=0ADan B=0A=C2-=0A=C2-=0Ahttp://www.matronics.com/N
avigator?AeroElectric-List=0Ahttp://forums.matronics.com=0Ahttp://www.matro
==
Message 17
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| Subject: | Re: Inexpensive CAD Software |
At 12:14 PM 6/13/2012, you wrote:
>Several months ago, I think I saw some traffic on this list about
>inexpensive CAD software.
>
>All I really need is some simple line-drawing & dimensioning
>capabilities to layout a panel.
>
>I used to use TurboCAD (~5-7 years ago). What's the hot ticket today?
I think TurboCAD rev7 or later will also open, edit,
save and print AutoCAD drawings which are posted
on my website. No doubt there are others. You can
get a really good deal on TurboCAD 8 right now
on eBay
http://tinyurl.com/bqwgnx2
Bob . . .
Message 18
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If it was me, I would change to the next larger fuse size (7.5amp).
Transmitting is not a sustained electrical condition. The fuse is to
protect the wire between the fuse and the radio. You may consider
metering the actual draw when transmitting for interest sake. You may find
that the draw is right close to 5 amps, causing the "nuisance" trips.
If the radio requires a certain amount of electrical power, and the voltage
supplied by the ebus is slightly lower due to the diode, then the current
draw has to rise slightly to compensate. Perhaps this is causing a slightly
higher draw (amps) when operating on the ebus as compared to the main bus..
My opinions only.
Bevan
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill
Schlatterer
Sent: Wednesday, June 13, 2012 11:16 AM
Subject: RE: AeroElectric-List: SL-40
Dan just curious, when you say lost . does that mean no power at all or no
transmit/receive power? Maybe only on the 430 but it seems like there are
two fuses. My SL40 just quit passing any audio to the headphones but still
appears to indicate RX/TX as if power is applied and it is working.
Bill S
RV7a
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dan
Billingsley
Sent: Wednesday, June 13, 2012 12:09 PM
Subject: AeroElectric-List: SL-40
Just when I thought I was out of the woods, an ole nemesis returns. As I
mentioned in the last post, my noise going into intercom was canceled by an
in-line audio suppressor.
Right after I did a run-up today getting ready to take off, I taxied to the
hold-short line and called the tower. I lost my radio. I got back to the
hanger to find for the second time I blew the 5 A fuse. The last time this
happened was 11 to 12 hours ago. The SL-40 is wired to the E-Bus. I am of
course concerned as to why this is happening, but know it could be a tough
one to nail down. My thoughts have led me to try running power from the main
bus but also using a DPDT switch to be able to flip the power to the radio
via the
E-bus should it go south again. Any other ideas are welcome.
Dan B
http://www.matronics.com/Navigator?AeroElectric-List
http://forums.matronics.com
http://www.matronics.com/contribution
Message 19
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Bevan,=0AThat is good logic in reference to the supplied voltage being a bi
t lower on the E-bus and kicking up the current. My D-100 is hooked up to t
he Main bus and my EIS (engine monitor) is on the the E bus. There is consi
stently about 1.5V lower being showed on the E-bus. I won't rule out the th
ought of the 7.5A fuse at a later date. I think I will see what happens cha
nging over to the main bus.=0AThank you for your input.=0ADan=0A=0A=0A_____
___________________________=0A From: B Tomm <fvalarm@rapidnet.net>=0ATo: ae
roelectric-list@matronics.com =0ASent: Wednesday, June 13, 2012 11:50 AM=0A
Subject: RE: AeroElectric-List: SL-40=0A =0A=0A =0AIf it was me, I would ch
ange to the next larger fuse size =0A(7.5amp).=C2- Transmitting is not a
sustained electrical condition.=C2- The =0Afuse is to protect the wire=C2
-between the fuse and the radio.=C2- =C2- =0AYou may consider meterin
g the actual draw when transmitting for interest =0Asake.=C2- You may fin
d that the draw is right close to 5 amps, causing the =0A"nuisance" trips.
=0A=C2-=0AIf the radio requires a certain amount of electrical power, =0A
and the voltage supplied by the ebus is slightly lower due to the diode, th
en =0Athe current draw has to rise slightly to compensate.=C2- Perhaps th
is is =0Acausing a slightly higher draw (amps) when operating on the ebus a
s compared to =0Athe main bus..=0A=C2-=0AMy opinions only.=0A=C2-=0ABev
an=0A=C2-=0A=0A=0A________________________________=0A From: owner-aeroele
ctric-list-server@matronics.com =0A[mailto:owner-aeroelectric-list-server@m
atronics.com] On Behalf Of Bill =0ASchlatterer=0ASent: Wednesday, June 13,
2012 11:16 AM=0ATo: aeroelectric-list@matronics.com=0ASubject: RE: AeroElec
tric-List: =0ASL-40=0A=0A=0ADan =0Ajust curious, when you say lost
does that mean no power at all or no =0Atransmit/receive power?=C2- M
aybe only on the 430 but it seems like there are =0Atwo fuses.=C2- My SL4
0 just quit passing any audio to the headphones but still =0Aappears to ind
icate RX/TX as if power is applied and it is working. =0A=C2-=0ABill =0AS
=0ARV7a=0A=C2-=0A=C2-=0A=C2-=0AFrom:owner-aeroelectric-list-server@ma
tronics.com =0A[mailto:owner-aeroelectric-list-server@matronics.com] On Beh
alf Of Dan =0ABillingsley=0ASent: Wednesday, June 13, 2012 12:09 PM=0ATo: a
eroelectric-list@matronics.com=0ASubject: AeroElectric-List: =0ASL-40=0A=C2
-=0AJust when I =0Athought I was out of the woods, an ole nemesis returns
. As I mentioned in the =0Alast post, my noise going into intercom was canc
eled by an in-line audio =0Asuppressor.=0ARight after I did =0Aa run-up tod
ay getting ready to take off, I taxied to the hold-short line and =0Acalled
the tower. I lost my radio. I got back to the hanger to find for the =0Ase
cond time I blew the 5 A fuse. The last time this happened was 11 to 12 hou
rs =0Aago. The SL-40 is wired to the E-Bus. I am of course concerned as to
why this is =0Ahappening, but know it could be a tough one to nail down. My
thoughts have led =0Ame to try running power from the main bus but also us
ing a DPDT switch to =0Abe able to flip the power to the radio via the=C2
-=0AE-busshould it go =0Asouth again. Any other ideas are welcome.=0ADan
=0AB=0A=C2-=0A=C2-=0Ahttp://www.matronics.com/Navigator?AeroElectric-Li
st=0Ahttp://forums.matronics.com=0Ahttp://www.matronics.com/contribution=0A
=C2-=0Ahref="http://www.matronics.com/Navigator?AeroElectric-List">http
://www.matronics.com/Navigator?AeroElectric-List=0Ahref="http://forums.ma
tronics.com">http://forums.matronics.com=0Ahref="http://www.matronics.com
=======
Message 20
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Probably way off base and a shot in the dark, but I discovered that it
is easy to blow the radio fuse if the APRS transmitter broadcasts its
periodic packet at the same time I press the transmit button. Separating
the antennas solved the problem.
john
On 6/13/2012 10:08 AM, Dan Billingsley wrote:
> Just when I thought I was out of the woods, an ole nemesis returns. As
> I mentioned in the last post, my noise going into intercom was
> canceled by an in-line audio suppressor.
> Right after I did a run-up today getting ready to take off, I taxied
> to the hold-short line and called the tower. I lost my radio. I got
> back to the hanger to find for the second time I blew the 5 A fuse.
> The last time this happened was 11 to 12 hours ago. The SL-40 is wired
> to the E-Bus. I am of course concerned as to why this is happening,
> but know it could be a tough one to nail down. My thoughts have led me
> to try running power from the *main bus *but also using a DPDT switch
> to be able to flip the power to the radio via the
> *E-bus* should it go south again. Any other ideas are welcome.
> Dan B
> *
>
>
> *
Message 21
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The 'low voltage=high current' thing works for AC induction motors, but
I wouldn't bet too heavily on it being the problem in a DC circuit. If
you look at the volts/ohms/amps formulas, you can see why.
One thing that *can* happen is the fuse will get hot if there's a poor
connection anywhere in the neighborhood: wire to terminal, terminal to
fuse, and back again on the other side of the fuse. Think resistance
heater. If it gets hot, it's weaker & vibration will increase the odds
of mechanical failure of the fuse link itself. Is it a glass fuse, or
one of the newer automotive blade type fuses? (Blade fuses should be
somewhat less susceptible to the high resistance issue.)
Can you monitor voltage at the power terminal of the radio, & watch the
voltage when you key the mic & actually transmit? If it drops
noticeably, you've got high resistance somewhere in the circuit, & the
fuse would be my 1st stop, especially if it's the old glass variety.
Charlie
On 06/13/2012 02:08 PM, Dan Billingsley wrote:
> Bevan,
> That is good logic in reference to the supplied voltage being a bit
> lower on the E-bus and kicking up the current. My D-100 is hooked up
> to the Main bus and my EIS (engine monitor) is on the the E bus. There
> is consistently about 1.5V lower being showed on the E-bus. I won't
> rule out the thought of the 7.5A fuse at a later date. I think I will
> see what happens changing over to the main bus.
> Thank you for your input.
> Dan
>
> ------------------------------------------------------------------------
> *From:* B Tomm <fvalarm@rapidnet.net>
> *To:* aeroelectric-list@matronics.com
> *Sent:* Wednesday, June 13, 2012 11:50 AM
> *Subject:* RE: AeroElectric-List: SL-40
>
> If it was me, I would change to the next larger fuse size (7.5amp).
> Transmitting is not a sustained electrical condition. The fuse is to
> protect the wire between the fuse and the radio. You may consider
> metering the actual draw when transmitting for interest sake. You may
> find that the draw is right close to 5 amps, causing the "nuisance" trips.
> If the radio requires a certain amount of electrical power, and the
> voltage supplied by the ebus is slightly lower due to the diode, then
> the current draw has to rise slightly to compensate. Perhaps this is
> causing a slightly higher draw (amps) when operating on the ebus as
> compared to the main bus..
> My opinions only.
> Bevan
>
> ------------------------------------------------------------------------
> *From:* owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] *On Behalf Of
> *Bill Schlatterer
> *Sent:* Wednesday, June 13, 2012 11:16 AM
> *To:* aeroelectric-list@matronics.com
> *Subject:* RE: AeroElectric-List: SL-40
>
> Dan just curious, when you say lost ... does that mean no power at all
> or no transmit/receive power? Maybe only on the 430 but it seems like
> there are two fuses. My SL40 just quit passing any audio to the
> headphones but still appears to indicate RX/TX as if power is applied
> and it is working.
> Bill S
> RV7a
> *From:*owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] *On Behalf Of
> *Dan Billingsley
> *Sent:* Wednesday, June 13, 2012 12:09 PM
> *To:* aeroelectric-list@matronics.com
> *Subject:* AeroElectric-List: SL-40
> Just when I thought I was out of the woods, an ole nemesis returns. As
> I mentioned in the last post, my noise going into intercom was
> canceled by an in-line audio suppressor.
> Right after I did a run-up today getting ready to take off, I taxied
> to the hold-short line and called the tower. I lost my radio. I got
> back to the hanger to find for the second time I blew the 5 A fuse.
> The last time this happened was 11 to 12 hours ago. The SL-40 is wired
> to the E-Bus. I am of course concerned as to why this is happening,
> but know it could be a tough one to nail down. My thoughts have led me
> to try running power from the *main bus *but also using a DPDT switch
> to be able to flip the power to the radio via the
> *E-bus*should it go south again. Any other ideas are welcome.
> Dan B
> * *
Message 22
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|
John,=0ANot off base at all...quite possibly a home run. I just installed a
n APRS unit and had it running. My antennas should not be an issue as they
are quite a ways apart, however I can keep that in mind while at the field
and turn it off until I get under way. Nice pitch, thanks!=0ADan=0A=0A=0A__
______________________________=0A From: John Morgensen <john@morgensen.com>
=0ATo: aeroelectric-list@matronics.com =0ASent: Wednesday, June 13, 2012 2:
42 PM=0ASubject: Re: AeroElectric-List: SL-40=0A =0A=0AProbably way off bas
e and a shot in the dark, but I discovered that it is easy to blow the radi
o fuse if the APRS transmitter broadcasts its periodic packet at the same t
ime I press the transmit button. Separating the antennas solved the problem
.=0A=0Ajohn=0A=0A=0AOn 6/13/2012 10:08 AM, Dan Billingsley wrote: =0AJust w
hen I thought I was out of the woods, an ole nemesis returns. As I mentione
d in the last post, my noise going into intercom was canceled by an in-line
audio suppressor.=0A>Right after I did a run-up today getting ready to tak
e off, I taxied to the hold-short line and called the tower. I lost my radi
o. I got back to the hanger to find for the second time I blew the 5 A fuse
. The last time this happened was 11 to 12 hours ago. The SL-40 is wired to
the E-Bus. I am of course concerned as to why this is happening, but know
it could be a tough one to nail down. My thoughts have led me to try runnin
g power from the main bus but also using a DPDT switch to be able to flip t
he power to the radio via the-=0A>E-bus should it go south again. Any oth
====
Message 23
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|
=0A=0A=0A=0A________________________________=0A From: Charlie England <ceen
gland@bellsouth.net>=0ATo: aeroelectric-list@matronics.com =0ASent: Wednesd
ay, June 13, 2012 5:08 PM=0ASubject: Re: AeroElectric-List: SL-40=0A =0A=0A
=0A=0AOne thing that *can* happen is the fuse will get hot if there's a=0A
poor connection anywhere in the neighborhood: wire to terminal,=0A te
rminal to fuse, and back again on the other side of the fuse.=0A Think r
esistance heater. If it gets hot, it's weaker & vibration=0A will increa
se the odds of mechanical failure of the fuse link=0A itself. Is it a gl
ass fuse, or one of the newer automotive blade=0A type fuses? (Blade fus
es should be somewhat less susceptible to the=0A high resistance issue.)
yes, they are the blade (automotive) type. Still something to look for.=C2
-=0A=0ACan you monitor voltage at the power terminal of the radio, &=0A
watch the voltage when you key the mic & actually transmit? If=0A it d
rops noticeably, you've got high resistance somewhere in the=0A circuit,
& the fuse would be my 1st stop, especially if it's the=0A old glass va
riety. I do have the ability to watch the voltage on each bus, so I will do
that test as well...thanks=0A=0ACharlie=0A=0AOn 06/13/2012 02:08 PM, Dan B
illingsley wrote: =0ABevan,=0A>That is good logic in reference to the suppl
ied voltage being a bit lower on the E-bus and kicking up the current. My D
-100 is hooked up to the Main bus and my EIS (engine monitor) is on the the
E bus. There is consistently about 1.5V lower being showed on the E-bus. I
won't rule out the thought of the 7.5A fuse at a later date. I think I wil
l see what happens changing over to the main bus.=0A>Thank you for your inp
ut.=0A>Dan=0A>=0A>=0A>=0A>________________________________=0A> From: B Tomm
<fvalarm@rapidnet.net>=0A>To: aeroelectric-list@matronics.com =0A>Sent: We
dnesday, June 13, 2012 11:50 AM=0A>Subject: RE: AeroElectric-List: SL-40=0A
> =0A>=0A> =0A>If it was me, I would change to the next larger fuse size (7
.5amp).=C2- Transmitting is not a sustained electrical condition.=C2- T
he fuse is to protect the wire=C2-between the fuse and the radio.=C2-
=C2- You may consider metering the actual draw when transmitting for inte
rest sake.=C2- You may find that the draw is right close to 5 amps, causi
ng the "nuisance" trips.=0A>=C2-=0A>If the radio requires a certain amoun
t of electrical power, and the voltage supplied by the ebus is slightly low
er due to the diode, then the current draw has to rise slightly to compensa
te.=C2- Perhaps this is causing a slightly higher draw (amps) when operat
ing on the ebus as compared to the main bus..=0A>=C2-=0A>My opinions only
.=0A>=C2-=0A>Bevan=0A>=C2-=0A>=0A>=0A>________________________________
=0A> From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroe
lectric-list-server@matronics.com] On Behalf Of Bill Schlatterer=0A>Sent: W
ednesday, June 13, 2012 11:16 AM=0A>To: aeroelectric-list@matronics.com=0A>
Subject: RE: AeroElectric-List: SL-40=0A>=0A>=0A>Dan just curious, when you
say lost does that mean no power at all or no transmit/receive p
ower?=C2- Maybe only on the 430 but it seems like there are two fuses.=C2
- My SL40 just quit passing any audio to the headphones but still appears
to indicate RX/TX as if power is applied and it is working. =0A>=C2-=0A>
Bill S=0A>RV7a=0A>=C2-=0A>=C2-=0A>=C2-=0A>From:owner-aeroelectric-lis
t-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com
] On Behalf Of Dan Billingsley=0A>Sent: Wednesday, June 13, 2012 12:09 PM
=0A>To: aeroelectric-list@matronics.com=0A>Subject: AeroElectric-List: SL-4
0=0A>=C2-=0A>Just when I thought I was out of the woods, an ole nemesis r
eturns. As I mentioned in the last post, my noise going into intercom was c
anceled by an in-line audio suppressor.=0A>Right after I did a run-up today
getting ready to take off, I taxied to the hold-short line and called the
tower. I lost my radio. I got back to the hanger to find for the second tim
e I blew the 5 A fuse. The last time this happened was 11 to 12 hours ago.
The SL-40 is wired to the E-Bus. I am of course concerned as to why this is
happening, but know it could be a tough one to nail down. My thoughts have
led me to try running power from the main bus but also using a DPDT switch
to be able to flip the power to the radio via the=C2-=0A>E-busshould it
==============
Message 24
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|
Dan;
You missed Charlie's point, the voltage at the buss doesn't tell the story
of a high resistance connection at the fuse or in the radio wiring. You must
monitor the voltage at the input terminal to the radio as Charlie indicated.
This should remain somewhat steady before and during transmit if all is well
with the circuit and it should closely approximate the buss voltage.
Bob McC
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dan
Billingsley
Sent: Wednesday, June 13, 2012 8:52 PM
Subject: Re: AeroElectric-List: SL-40
_____
From: Charlie England <ceengland@bellsouth.net>
Sent: Wednesday, June 13, 2012 5:08 PM
Subject: Re: AeroElectric-List: SL-40
One thing that *can* happen is the fuse will get hot if there's a poor
connection anywhere in the neighborhood: wire to terminal, terminal to fuse,
and back again on the other side of the fuse. Think resistance heater. If it
gets hot, it's weaker & vibration will increase the odds of mechanical
failure of the fuse link itself. Is it a glass fuse, or one of the newer
automotive blade type fuses? (Blade fuses should be somewhat less
susceptible to the high resistance issue.) yes, they are the blade
(automotive) type. Still something to look for.
Can you monitor voltage at the power terminal of the radio, & watch the
voltage when you key the mic & actually transmit? If it drops noticeably,
you've got high resistance somewhere in the circuit, & the fuse would be my
1st stop, especially if it's the old glass variety. I do have the ability to
watch the voltage on each bus, so I will do that test as well...thanks
Charlie
Message 25
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|
exactly; thanks, Bob
On 06/13/2012 08:20 PM, Bob McCallum wrote:
>
> *Dan;*
>
> **
>
> *You missed Charlie's point, the voltage at the buss doesn't tell the
> story of a high resistance connection at the fuse or in the radio
> wiring. You must monitor the voltage _at the input terminal to the
> radio_ as Charlie indicated. This should remain somewhat steady before
> and during transmit if all is well with the circuit and it should
> closely approximate the buss voltage.*
>
> **
>
> *Bob McC*
>
> **
>
> ------------------------------------------------------------------------
>
> *From:*owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] *On Behalf Of
> *Dan Billingsley
> *Sent:* Wednesday, June 13, 2012 8:52 PM
> *To:* aeroelectric-list@matronics.com
> *Subject:* Re: AeroElectric-List: SL-40
>
> ------------------------------------------------------------------------
>
> *From:*Charlie England <ceengland@bellsouth.net>
> *To:* aeroelectric-list@matronics.com
> *Sent:* Wednesday, June 13, 2012 5:08 PM
> *Subject:* Re: AeroElectric-List: SL-40
>
>
> One thing that *can* happen is the fuse will get hot if there's a poor
> connection anywhere in the neighborhood: wire to terminal, terminal to
> fuse, and back again on the other side of the fuse. Think resistance
> heater. If it gets hot, it's weaker & vibration will increase the odds
> of mechanical failure of the fuse link itself. Is it a glass fuse, or
> one of the newer automotive blade type fuses? (Blade fuses should be
> somewhat less susceptible to the high resistance issue.) yes, they are
> the blade (automotive) type. Still something to look for.
>
> Can you monitor voltage at the power terminal of the radio, & watch
> the voltage when you key the mic & actually transmit? If it drops
> noticeably, you've got high resistance somewhere in the circuit, & the
> fuse would be my 1st stop, especially if it's the old glass variety. I
> do have the ability to watch the voltage on each bus, so I will do
> that test as well...thanks
>
> Charlie
>
>
> **
>
> * *
> *
>
>
> *
Message 26
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Dan,
I can't tell from your description if you are talking about the fuse to the
radio or the fuse to the e-buss. If it is the fuse to the radio, you must
have something wrong with the radio because it only pulls about 2 amps when
you transmit, much less to receive.
If you are talking about the fuse to the e-buss, then you are having the
same problem that I did with my radio. I had all the stuff that I felt I
needed in an emergency going thru the e-buss and following the architecture
of Z-19, I had a 7.5 amp fuse on the e-buss.
I had tested everything and it was working fine. This day I was letting the
autopilot fly and decided to go back to the airport. I picked up ATIS, then
tuned in approach and keyed the mike. About 15 seconds and POP! the entire
panel went dark! I sat there stunned! Well, the engine is still running!
You need to size the fuse on the e-buss to handle the total load on the
e-buss! If a 2 amp load is blowing a 5 amp fuse, you have the e-buss loaded
to about 4+ amps before you hit transmit. Or write the light signals down
so you will have them available! :>)
Bill B
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dan
Billingsley
Sent: Wednesday, June 13, 2012 8:23 PM
Subject: Re: AeroElectric-List: SL-40
John,
Not off base at all...quite possibly a home run. I just installed an APRS
unit and had it running. My antennas should not be an issue as they are
quite a ways apart, however I can keep that in mind while at the field and
turn it off until I get under way. Nice pitch, thanks!
Dan
_____
From: John Morgensen <john@morgensen.com>
Sent: Wednesday, June 13, 2012 2:42 PM
Subject: Re: AeroElectric-List: SL-40
Probably way off base and a shot in the dark, but I discovered that it is
easy to blow the radio fuse if the APRS transmitter broadcasts its periodic
packet at the same time I press the transmit button. Separating the antennas
solved the problem.
john
On 6/13/2012 10:08 AM, Dan Billingsley wrote:
Just when I thought I was out of the woods, an ole nemesis returns. As I
mentioned in the last post, my noise going into intercom was canceled by an
in-line audio suppressor.
Right after I did a run-up today getting ready to take off, I taxied to the
hold-short line and called the tower. I lost my radio. I got back to the
hanger to find for the second time I blew the 5 A fuse. The last time this
happened was 11 to 12 hours ago. The SL-40 is wired to the E-Bus. I am of
course concerned as to why this is happening, but know it could be a tough
one to nail down. My thoughts have led me to try running power from the main
bus but also using a DPDT switch to be able to flip the power to the radio
via the
E-bus should it go south again. Any other ideas are welcome.
Dan B
Message 27
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|
For what it's worth, in my load analysis, by the GNS-430 VHF com circuit I
have written "3.2-6 amps" during the transmit condition, with 4ma-15ma in
the receive condition. I'm pretty sure I got that from the Garmin
installation manual. I know your radio was made by someone else, but I
mention it to help promote the possibility that 5 amps might be a realistic
current for a similar VHF radio. The fuse might be doing just what it's
been asked to do.
On Wed, Jun 13, 2012 at 9:27 PM, Charlie England <ceengland@bellsouth.net>w
rote:
> exactly; thanks, Bob
>
>
> On 06/13/2012 08:20 PM, Bob McCallum wrote:
>
> **
>
> *Dan;*
>
> * *
>
> *You missed Charlie=92s point, the voltage at the buss doesn=92t tell the
> story of a high resistance connection at the fuse or in the radio wiring.
> You must monitor the voltage at the input terminal to the radio as
> Charlie indicated. This should remain somewhat steady before and during
> transmit if all is well with the circuit and it should closely approximat
e
> the buss voltage.*
>
> * *
>
> *Bob McC*
>
> * *
> ------------------------------
>
> *From:* owner-aeroelectric-list-server@matronics.com [
> mailto:owner-aeroelectric-list-server@matronics.com<owner-aeroelectric-li
st-server@matronics.com>]
> *On Behalf Of *Dan Billingsley
> *Sent:* Wednesday, June 13, 2012 8:52 PM
> *To:* **aeroelectric-list@matronics.com**
> *Subject:* Re: AeroElectric-List: SL-40****
>
> ** **
>
> ** **
>
> ** **
> ------------------------------
>
> *From:* Charlie England <ceengland@bellsouth.net><ceengland@bellsouth.net
>
> *To:* **aeroelectric-list@matronics.com**
> *Sent:* Wednesday, June 13, 2012 5:08 PM
> *Subject:* Re: AeroElectric-List: SL-40****
>
> ** **
>
>
> One thing that *can* happen is the fuse will get hot if there's a poor
> connection anywhere in the neighborhood: wire to terminal, terminal to
> fuse, and back again on the other side of the fuse. Think resistance
> heater. If it gets hot, it's weaker & vibration will increase the odds of
> mechanical failure of the fuse link itself. Is it a glass fuse, or one of
> the newer automotive blade type fuses? (Blade fuses should be somewhat le
ss
> susceptible to the high resistance issue.) yes, they are the blade
> (automotive) type. Still something to look for.
>
> Can you monitor voltage at the power terminal of the radio, & watch the
> voltage when you key the mic & actually transmit? If it drops noticeably,
> you've got high resistance somewhere in the circuit, & the fuse would be
my
> 1st stop, especially if it's the old glass variety. I do have the ability
> to watch the voltage on each bus, so I will do that test as well...thanks
>
> Charlie
>
>
> **
>
> * *
>
> *
>
> *
>
> **
>
>
> *
>
===========
===========
===========
===========
> *
>
>
Message 28
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|
| Subject: | Re: Inexpensive CAD Software |
Jeff, I bought Turbo Cad (version 15 I think) for less than $15. Asked my
buddy who's a Cad manager in a large engineering Co to teach me how to use
it. He didn't like Turbo Cad, way too complex for basic line drawings for
aircraft schematics. He suggested "Smart Draw". Search the web and give
it a try. It's a lot more user friendly.
Rick
RV10 #40956
Southampton, Ont
On Wed, Jun 13, 2012 at 1:14 PM, Jeff Luckey <JLuckey@pacbell.net> wrote:
> Several months ago, I think I saw some traffic on this list about
> inexpensive CAD software. ****
>
> ** **
>
> All I really need is some simple line-drawing & dimensioning capabilities
> to layout a panel. ****
>
> ** **
>
> I used to use TurboCAD (~5-7 years ago). What=92s the hot ticket today?*
***
>
> ** **
>
> ** **
>
> -Jeff****
>
> ** **
>
> *
>
===========
===========
===========
===========
> *
>
>
Message 29
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|
Thanks guys, That gives me info to work with. Will let you know what I find
tomorrow.=0ADan=0A=0A=0A________________________________=0A From: Jared Ya
tes <email@jaredyates.com>=0ATo: aeroelectric-list@matronics.com =0ASent: W
ednesday, June 13, 2012 6:56 PM=0ASubject: Re: AeroElectric-List: SL-40=0A
=0A=0AFor what it's worth, in my load analysis, by the GNS-430 VHF com circ
uit I have written "3.2-6 amps" during the transmit condition, with 4ma-15m
a in the receive condition. =C2-I'm pretty sure I got that from the Garmi
n installation manual. =C2-I know your radio was made by someone else, bu
t I mention it to help promote the possibility that 5 amps might be a reali
stic current for a similar VHF radio. =C2-The fuse might be doing just wh
at it's been asked to do.=0A=0A=0AOn Wed, Jun 13, 2012 at 9:27 PM, Charlie
England <ceengland@bellsouth.net> wrote:=0A=0Aexactly; thanks, Bob=0A>=0A>
=0A>On 06/13/2012 08:20 PM, Bob McCallum wrote: =0A> =0A>>Dan;=0A>>=C2-
=0A>>You=0Amissed Charlie=99s point, the voltage at the buss doesn
=99t tell the story of a high resistance connection at the fuse or in th
e radio wiring. You must monitor the voltage at the input terminal to the r
adio as Charlie indicated. This should remain somewhat steady before and du
ring transmit if all is well with the circuit and it should closely approxi
mate the buss voltage.=0A>>=C2-=0A>>Bob McC=0A>>=C2-=0A>>=0A>>_________
_______________________=0A>> =0A>>From:owner-aeroelectric-list-server@matro
nics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Dan Billingsley=0A>>Sent: Wednesday, June 13, 2012 8:52 PM=0A>>To: aeroele
ctric-list@matronics.com=0A>>Subject: Re: AeroElectric-List: SL-40=0A>>=C2
-=0A>>=C2-=0A>>=C2-=0A>>=0A>>________________________________=0A>>
=0A>>From:Charlie England <ceengland@bellsouth.net>=0A>>To: aeroelectric-li
st@matronics.com =0A>>Sent: Wednesday, June 13, 2012 5:08 PM=0A>>Subject: R
e: AeroElectric-List: SL-40=0A>>=C2-=0A>>=0A>>=0A>>One thing that *can* h
appen is the fuse will=0A get hot if there's a p
oor=0A connection anywhere in the neighborhood:
=0A wire to terminal, terminal to fuse,=0A
and back again on the other side of the=0A
fuse. Think resistance heater. If it=0A
gets hot, it's weaker & vibration will=0A
increase the odds of mechanical=0A failure of
the fuse link itself. Is it a=0A glass fuse, or
one of the newer=0A automotive blade type fuses
? (Blade fuses=0A should be somewhat less suscep
tible=0A to the high resistance issue.) yes, the
y are the blade (automotive) type. Still something to look for.=C2-=0A>>
=0A>>Can you monitor voltage at the power=0A ter
minal of the radio, & watch the=0A voltage when
you key the mic & actually=0A transmit? If it dr
ops noticeably,=0A you've got high resistance so
mewhere in the=0A circuit, & the fuse would be m
y=0A 1st stop, especially if it's the old glass
=0A variety. I do have the ability to watch the
voltage on each bus, so I will do that test as well...thanks=0A>>=0A>>Charl
ie=0A>>=0A>>=0A>>=0A>>=C2-=0A>=0A>ist" target="_blank">http://www.matro
nics.com/Navigator?AeroElectric-List=0Atp://forums.matronics.com=0A_blank">
=======
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