VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-12
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #11  
Old 09-13-2017, 08:02 AM
rgmwa rgmwa is offline
 
Join Date: Feb 2010
Location: Perth, Western Australia
Posts: 1,545
Default

Not yet Tom. Haven't had a chance to get back to the hangar, but will post here if I can track it down. It's a steady tone, rather than a typical feedback squeal, which I've had before and fixed by slaving the side tone to the volume control. The tone continues as long as either PTT button is held down. It's probably something simple (I hope).
__________________
rgmwa
120346
Reply With Quote
  #12  
Old 09-13-2017, 01:41 PM
todehnal todehnal is offline
 
Join Date: Jan 2005
Location: Kentucky Lakes area in KY
Posts: 888
Default

Quote:
Originally Posted by rgmwa View Post
Not yet Tom. Haven't had a chance to get back to the hangar, but will post here if I can track it down. It's a steady tone, rather than a typical feedback squeal, which I've had before and fixed by slaving the side tone to the volume control. The tone continues as long as either PTT button is held down. It's probably something simple (I hope).
My reason for asking is that I think we have similar issues. I've played with all of the settings on the SL40, including slaving the side tone to the volume control and I can reduce it, but not eliminate the squeal/hum in transmit. I'm planning to work on the antenna connections next. If I find a fix, I will let you know as well. I have noticed that it is not as noticeable in flight. It is much more annoying during taxi and while parked, even with the engine shut down. ........Tom
__________________
2013- RV12, Kit #119. N123M First flight Nov21. It's a keeper!
1998- RV-9 tail kit, built and sold
1989- RV-6 tail kit, built and sold
Reply With Quote
  #13  
Old 09-13-2017, 02:39 PM
noelf noelf is offline
 
Join Date: Nov 2007
Location: Cary, N.C.
Posts: 1,028
Default

Another thought: I seem to remember in the back of SL 40 Instalation Manual there is a very simplified wiring diagram of an installation using the SL 40 as the 2 -place intercom.

You could pull the radio out of the plane, wire up a 25-pin D shell connector following the wiring diagram with connections for headphone and mic and PTT connections, hook up a 12 volt battery, connect a small coax and antenna and jumper for the internal intercom function.

This setup is what I fabricated in a role around cooler for a portable ground setup that I use when I communicate with our formation flight team.
__________________
Noel
RV-6A N6NF
tip-up
flying

Last edited by noelf : 09-13-2017 at 02:46 PM.
Reply With Quote
  #14  
Old 09-13-2017, 02:45 PM
noelf noelf is offline
 
Join Date: Nov 2007
Location: Cary, N.C.
Posts: 1,028
Default

Which brings up another thought: on your SL 40 install, be sure the pin position for the selection of "internal intercom" function is not populated. I do not know what symptom would show if the internal intercom function was wired and you also used an external intercom box.
__________________
Noel
RV-6A N6NF
tip-up
flying
Reply With Quote
  #15  
Old 09-17-2017, 06:42 AM
rgmwa rgmwa is offline
 
Join Date: Feb 2010
Location: Perth, Western Australia
Posts: 1,545
Default

Got down to the hangar today, plugged in the headset, turned the master and avionics on and Skyview off, pressed the PTT and sure enough the loud tone was there again. Made sure the SL40 was fully seated and locked as per Joe's suggestion, which it was. Then thought I might as well pull it out and have a look anyway. Turned everything off, unlocked and pulled the radio out, examined the aerial connector and D-sub, and still none the wiser, pushed it back home and locked it again. Master and avionic back on, hit the PTT and made a test call, and presto - no noise. Great result!

Feeling pleased with my apparent mastery of electronics, I pulled the plane out to go flying. Settled in, started the engine, flipped all the required switches and pressed the PTT to make a departure call, only to hear the dreaded noise again, although not as bad as before. Took off and flew around for a hour. Reception was fine. Called up another aircraft that had just landed at a field about 8nm away to ask for a radio check and was told readable but `crackly'. When making the call, the interference at my end didn't seem too bad, but by the time I arrived back at my home airfield the noise during radio calls was as bad as ever.

The plane is now down for its annual, and I will be away for the next 2-3 weeks, so any further troubleshooting will have to wait. My current prime suspect is the antenna cable or its connections, unless any of you electronics experts out there have any better ideas.
__________________
rgmwa
120346

Last edited by rgmwa : 09-17-2017 at 07:24 AM.
Reply With Quote
  #16  
Old 09-17-2017, 06:56 AM
JBPILOT JBPILOT is offline
 
Join Date: Nov 2007
Location: Jesup, Iowa
Posts: 1,562
Default Way back when - -

I had an issue with a crimp and the antenna end of the coax cable. Some just did not get a good crimp of the tiny center wire. Fixed and it solved it for a few year now anyway.
__________________
John Bender
Flying RV-12 - Serial #120036
Paid in May ( 5-10-17 )
Reply With Quote
  #17  
Old 09-17-2017, 07:08 AM
rgmwa rgmwa is offline
 
Join Date: Feb 2010
Location: Perth, Western Australia
Posts: 1,545
Default

I wouldn't be surprised if it was something like that John, although I've been known to be wrong before.
__________________
rgmwa
120346
Reply With Quote
  #18  
Old 10-02-2017, 09:28 PM
Azjulian Azjulian is offline
 
Join Date: Dec 2015
Location: Scottsdale, Arizona
Posts: 123
Default

If you disconnect the just the mic plug of your headset do you still get the sound ?
Reply With Quote
  #19  
Old 10-02-2017, 09:30 PM
Azjulian Azjulian is offline
 
Join Date: Dec 2015
Location: Scottsdale, Arizona
Posts: 123
Default

And / or if you turn sidetone off completely on the radio do you still get the noise ? That would determine if itís introdroduced through the sidetone circuit
Reply With Quote
  #20  
Old 10-16-2017, 08:26 AM
Dgamble's Avatar
Dgamble Dgamble is offline
 
Join Date: Aug 2005
Posts: 808
Default

I had very similar symptoms, in addition to a very touchy headset jack - least bump and I would lose audio. I just finished my annual and while I had the wings off, I tried running a dedicated ground wire from the ground lug of the audio headset jack to a firm ground on the airframe. It made a world of difference. I'm not proposing that exact fix for you, but it would be easy to test while you have the wings off.
__________________
Dave Gamble
Grove City, OH

RV-6 N466PG Purchased already flying - SOLD!

Built RV-12
http://www.schmetterlingaviation.com

The above web blogs and any links provided thereto are not instructional or advisory in nature. They merely seek to share my experiences in building and flying Van's RV airplanes.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 05:24 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.