Today's Message Index:
----------------------
0. 12:25 AM - Make Sure You're Listed! (Matt Dralle)
1. 08:51 AM - Radio noise (Philip Smith)
2. 09:25 AM - Re: Radio noise (Paul Mulwitz)
3. 10:27 AM - Re: Radio noise (Gary Ray)
4. 10:27 AM - Re: Radio noise (FLYaDIVE)
Message 0
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Make Sure You're Listed! |
Dear Listers,
The List of Contributors (LOC) is just around the corner with just two more days
in this year's Fund Raiser! Later in December I will post a list of everyone
that so generously made a Contribution to support the Lists this year. Its
my way of publicly thanking everyone that took a minute to show their appreciation
for the Lists.
Won't you take minute and assure that your name is on the upcoming LOC? Tell others
that you appreciate the Lists.
Making a Contribution to support the Lists is fast and easy using your Visa, MasterCard,
or Paypal account:
http://www.matronics.com/contribution
Or, by dropping a personal check in the mail to:
Matt Dralle / Matronics
581 Jeannie Way
Livermore CA 94550
I would like to thank everyone that has so generously made a Contribution thus
far during this year's List Fund Raiser! Remember that its YOUR support that
keeps these Lists running and improving!
Thank you!
Matt Dralle
Matronics Email List Administrator
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
I know this has been discussed before but like to ask anyway. I installed
an *old* RST 360 com radio in my 701 panel and when I start the "Rotax" it
is very noisy. Seems to be a whine don't know whether or not this is
alternator or ignition. Saw a wiring diagram for another radio which stated
that you must install a 22,000uf capacitor in series on the 12v feed when
used with the Rotax engine installation. Will this cure the problem? Your
valued thoughts please.
Phil Smith
CH 701 - Flying
Buhl, ID
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Hi Phil,
If you put a capacitor in series with your power feed to anything it will
stop working - any capacitor blocks Direct Current and passes some amount of
Alternating Current. If you want to filter the 12V power you must connect
the capacitor between the 12V line and the return line or ground. If you
want to try this I would recommend a much smaller capacitor to start -
perhaps 50 or 100 microfarads. These are small ceramic (disks?) available
at Radio Shack for about the price of the blister package. If you install
one near the radio it might help reduce radio frequency noise going to the
radio power supply. Still, I don't think this is your problem.
I don't have personal experience with this problem, but I have been reading
comments about it for years. The usual solution is to work on the ground
path between your headset and radio. It requires a good shielded ground
path directly to the radio to work properly. This is usually accomplished
by using coaxial cable for the circuit between the radio and headset in both
the microphone and earphone paths. This solution works on the principle
that it is the audio circuit that picks up the noise rather than the power
supply to the radio.
If that doesn't solve your problem I would suggest working on the ground
path to your radio from the battery. I have a large copper braid in my
plane for this purpose. It runs all the way from the battery negative
terminal to the instrument panel. This helps the power supply in the radio
do its job.
Good luck,
Paul
Camas, WA
XL installing upgrade
From: owner-zenith-list-server@matronics.com
[mailto:owner-zenith-list-server@matronics.com] On Behalf Of Philip Smith
Sent: Monday, November 29, 2010 8:47 AM
zenith-list@matronics.com
Subject: Zenith-List: Radio noise
I know this has been discussed before but like to ask anyway. I installed
an old RST 360 com radio in my 701 panel and when I start the "Rotax" it is
very noisy. Seems to be a whine don't know whether or not this is alternator
or ignition. Saw a wiring diagram for another radio which stated that you
must install a 22,000uf capacitor in series on the 12v feed when used with
the Rotax engine installation. Will this cure the problem? Your valued
thoughts please.
Phil Smith
CH 701 - Flying
Buhl, ID
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Phil
I had a similar problem with my XCom. To find it I Started pulling
fuses one by one to test for any circuit that may be causing the
problem.
When I got to the accessory power circuit to the rear of the aircraft it
stopped.
My headset wiring was shielded over the entire length except the last 2
inches. Interference got in at the distal 2 inches where it was
unshielded and ran too close to a small linear switching voltage
regulator output wires.
Another problem was the intercom squelch not set high enough which
caused an unbearable
interference at take off power even though my headset was the only one
plugged in.
The large capacitor is used across the charging circuit to filter the
dynamo output as it enters the battery bus. Check out the
Aeroelectric.com site for the details and correct capacitor.
Gary Ray
From: Philip Smith
Sent: Monday, November 29, 2010 11:47 AM
zenith-list@matronics.com
Subject: Zenith-List: Radio noise
I know this has been discussed before but like to ask anyway. I
installed an old RST 360 com radio in my 701 panel and when I start the
"Rotax" it is very noisy. Seems to be a whine don't know whether or not
this is alternator or ignition. Saw a wiring diagram for another radio
which stated that you must install a 22,000uf capacitor in series on the
12v feed when used with the Rotax engine installation. Will this cure
the problem? Your valued thoughts please.
Phil Smith
CH 701 - Flying
Buhl, ID
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Phil:
A WHINE is an ALTERNATOR issue.
If you had a rough hashing sound then it would be ignition.
In either case the sound should increase in frequency as the engine
increased in speed (RPM).
The 22,000 uF capacitor (or larger 33,000 or 50,000 uF @ 16WVDC) goes IN
PARALLEL with the B+ wire coming from your Alternator. Got that? NOT in
series.
It goes from the B+ terminal (the Positive side of the Capacitor) - To
GROUND / GND (the Negative side of the Capacitor). ---| (--- The side to
the left is the Positive.
Let me know if you understand what I'm saying.
As far as curring the problem.... I don't know, I have ONLY
your expiation of the problem go diagnose by.
Barry
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|