What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Transponder Woes......

petehowell

petehowell

Well Known Member
Need some help from the Gurus!

I have a Collins TDR-950 transponder in the -9A and over the last week it has been wonky(technical term). When cold, it fires ups and transponds just fine, but about 10-15 min after launch, it goes tango uniform. No reply light, nuthin'. I checked with ATC, Even "ident" does not work when it is not transponding.

More info: Shut her down for a while and she will work again for another 15 min or so. The reply light fires up when the switch is set to test and when ident is pushed.

Any thoughts for trouble shooting or repair? I know this thing is as old as I am and I got it cheap, so no regrets. The question is if it is worth fixing - If the cavity tube is blown will it work at all?

Dropping in a Garmin 320 would be the plan, but it will require some panel rework b/c the Garmin is quite a bit longer.

BTW, ATC In Minne and Madsion were great about working with me and the issue - they just asked to get it fixed ASAP.

Thanks for any help!!
 
It could be the power supply, the tube or any number of things, bottom line....Do yourself a favor and go get the Garmin, the old gal just ain't worth fixin.
 
Pete,

Its been a while since I worked on those units but it sounds like the power supply may be the problem. Since it is an issue after a given amount of time I would think a bad capacitor or diode. Also since you are not getting a reply light I don't think you have a bad tube. Might cost a few hundred just to look at it, so it is up to you what is worth sinking into it. I can recommend the shop I used to work at if you don't feel you have someone local to look at.


Jay
 
Pete,

I do bench repair of older transponders. Call me at 817-422-2714. No charge if I can't fix it.

Mike
 
Thanks Mike

Mike F said:
Pete,

I do bench repair of older transponders. Call me at 817-422-2714. No charge if I can't fix it.

Mike
Click to expand...

Just a quick to note of praise for Mike at North Texas Avionics. I sent him my flaky transponder and he tried to revive it - kept me in the loop on the process, but ultimately the power supply was not repairable. As promised, no charge other than shipping.

Mike is on my RV good guy list.
 
You must log in or register to reply here.
Back
Top