Becker Transponder E10 error message

On Friday, May 11, 2018 at 5:10:14 PM UTC-4, Steve Cameron wrote:
I've recently bought a glider that has an older Becker transponder(mode c), and every time I turn it on it invariably displays the E10 error code. In reading past reports of this issue(2006/2008) on the net this seemed to be a fairly common occurence, with no real solution. Becker says its a transmission fault involving the antenna and or ground plane. My local avionics shop tested it for the two-year cert, everything checked out OK, than at the end of the check the E10 pops up. We've tried adding a short piece of coax at the antenna end, as well as insuring the ground plane is truly grounded. So far nothing seems to rid the error message. My avionic tech here seems to think it was a design flaw in the unit, and I'm very tempted to just scrap it and move on. Is there anyone out there who has successfully dealt with this issued?
Thanks
SC

Darrel, your comment about making sure the BNC connector made good contact with the aluminum foil ground plane seemed to do the trick. I doubled up some heavy duty tin foil and placed it over the top of the antenna stub that the bnc connects to, than attached the bnc connector for a tight fit. I turned the transponder on and ran for @ 30 minutes, with no E10 message. Hopefully this will be the last of that problem!

Thanks again!
SC

On Saturday, May 12, 2018 at 3:02:09 PM UTC-4, Steve Cameron wrote:
On Friday, May 11, 2018 at 5:10:14 PM UTC-4, Steve Cameron wrote:
I've recently bought a glider that has an older Becker transponder(mode c), and every time I turn it on it invariably displays the E10 error code. In reading past reports of this issue(2006/2008) on the net this seemed to be a fairly common occurence, with no real solution. Becker says its a transmission fault involving the antenna and or ground plane. My local avionics shop tested it for the two-year cert, everything checked out OK, than at the end of the check the E10 pops up. We've tried adding a short piece of coax at the antenna end, as well as insuring the ground plane is truly grounded. So far nothing seems to rid the error message. My avionic tech here seems to think it was a design flaw in the unit, and I'm very tempted to just scrap it and move on. Is there anyone out there who has successfully dealt with this issued?
Thanks
SC

Darrel, your comment about making sure the BNC connector made good contact with the aluminum foil ground plane seemed to do the trick. I doubled up some heavy duty tin foil and placed it over the top of the antenna stub that the bnc connects to, than attached the bnc connector for a tight fit. I turned the transponder on and ran for @ 30 minutes, with no E10 message. Hopefully this will be the last of that problem!

Thanks again!
SC

Steve,

my 4401 has a threaded BNC connector in the back. I bought a new threaded-to-bayonet adapter to make sure I have a good and rattle-free connection.
As for the ground plane, I have some 'real estate' behind the seats and installed a ground plane about 1.5ft x 1.5ft. The guy who did my transponder check and sign-off liked it.

Uli
'AS'

On Saturday, May 12, 2018 at 7:33:35 PM UTC-7, AS wrote:
/snip/
Steve,

my 4401 has a threaded BNC connector in the back. I bought a new threaded-to-bayonet adapter to make sure I have a good and rattle-free connection.
As for the ground plane, I have some 'real estate' behind the seats and installed a ground plane about 1.5ft x 1.5ft. The guy who did my transponder check and sign-off liked it.

Uli
'AS'

I'm not sure this really great advice. Sure it seems to work, but you are adding unneeded complexity to the RC coax signal path. The reason that many transponders use a TNC not a BNC connector in the first place is that TNCs are better connectors at the 1 GHz frequencies that transponders operate at. If something appears too loose then possibly the TNC plug is not correctly installed on the coax, and then maybe the BNCs are not either but just "feel better". I'm more concerned here that there was possibly some bad coax terminations happening that needed to be worked around. And it's just an unnecessary extra connection that may have problems.

Connection quality at 1 GHz is more critical, and less forgiving, than say the many sins you can get away with at VHF radio frequencies. And sure it might work fine, but you don't really know what little things like unneeded adapters or possible bad cable terminations are costing you in output performance.

I would really encourage everybody to try to follow manufacturers install inductions. Those install manuals describe the proper TNC coax connector and coax cable to use. It is important to use specific convectors designed to mate with the exact coax type (or in some case exact brand/cable version) you have. If things are not fitting properly that may be the problem. Tolerances for all these connectors are pretty tight, and it takes practice to terminate a coax really well. Have a pro do it for you, or better show you how to do it. Even coax that looks very similar may require different coax connectors and crimp tools/dies (if they are crimp on... and crimp is usually the best *if* you have the right crimp tooling,... which may get unjustifiably expensive for occasional work.).

BTW I was just reading the Trig Europe EASA minor change install documentation for gliders, https://www.trig-avionics.com/librar...2X.002-4.0.pdf and there is good stuff there as well as in their standard install manuals. Becker documentation is usually great as well.

And an aside: In some respects passing the transponder RF check is a pretty low-bar.... it will find gross errors--and in the post that started this thread it sounded like the transponder passed the test but then failed itself with an E10 error. Those tests come from the distant past where a large part for them, and certainly the biannual checks was detecting degradation of traveling wave tube based transponders. And maybe with solid state transponders the test period for RF tests should have been increased..

On Sunday, May 13, 2018 at 12:05:00 AM UTC-4, Darryl Ramm wrote:
On Saturday, May 12, 2018 at 7:33:35 PM UTC-7, AS wrote:
/snip/
Steve,

my 4401 has a threaded BNC connector in the back. I bought a new threaded-to-bayonet adapter to make sure I have a good and rattle-free connection..
As for the ground plane, I have some 'real estate' behind the seats and installed a ground plane about 1.5ft x 1.5ft. The guy who did my transponder check and sign-off liked it.

Uli
'AS'

I'm not sure this really great advice. Sure it seems to work, but you are adding unneeded complexity to the RC coax signal path. The reason that many transponders use a TNC not a BNC connector in the first place is that TNCs are better connectors at the 1 GHz frequencies that transponders operate at. If something appears too loose then possibly the TNC plug is not correctly installed on the coax, and then maybe the BNCs are not either but just "feel better". I'm more concerned here that there was possibly some bad coax terminations happening that needed to be worked around. And it's just an unnecessary extra connection that may have problems.

Connection quality at 1 GHz is more critical, and less forgiving, than say the many sins you can get away with at VHF radio frequencies. And sure it might work fine, but you don't really know what little things like unneeded adapters or possible bad cable terminations are costing you in output performance.

I would really encourage everybody to try to follow manufacturers install inductions. Those install manuals describe the proper TNC coax connector and coax cable to use. It is important to use specific convectors designed to mate with the exact coax type (or in some case exact brand/cable version) you have. If things are not fitting properly that may be the problem. Tolerances for all these connectors are pretty tight, and it takes practice to terminate a coax really well. Have a pro do it for you, or better show you how to do it. Even coax that looks very similar may require different coax connectors and crimp tools/dies (if they are crimp on... and crimp is usually the best *if* you have the right crimp tooling,... which may get unjustifiably expensive for occasional work.).

BTW I was just reading the Trig Europe EASA minor change install documentation for gliders, https://www.trig-avionics.com/librar...2X.002-4.0.pdf and there is good stuff there as well as in their standard install manuals. Becker documentation is usually great as well.

And an aside: In some respects passing the transponder RF check is a pretty low-bar.... it will find gross errors--and in the post that started this thread it sounded like the transponder passed the test but then failed itself with an E10 error. Those tests come from the distant past where a large part for them, and certainly the biannual checks was detecting degradation of traveling wave tube based transponders. And maybe with solid state transponders the test period for RF tests should have been increased..

Thanks for the reply and additional information, Darryl! I did look for a co-ax cable specified by Becker with a TNC on one end and a BNC on the antenna end but couldn't find one in the required length. Should I see any issues creeping up, I will ask the avionics guy, who did the sign-off to make up a custom cable.
Uli
'AS'

Craggy Aero has them

http://www.craggyaero.com/electrical.htm

PN 3003015

Richard
www.craggyaero.com