Becker Transponder E10 error message

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

On Friday, May 11, 2018 at 2:10:14 PM UTC-7, 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

What Becker transponder model? A 4401 for example in working order with encoder seem to go for ~US$600, a Becker TT22 (the only new transponder I'd buy for a glider today) is ~$1,900 so that gives you a repair cost range to work with. Assuming you are in the USA, Becker service here has been pretty good with quotes and turn around in the past.

What exact antenna and what ground plane? Carbon of fiberglas fuselage?

Does it only happen on the ground? What surface is the glider/antenna over when this happened. Does it happen when you are flying? It may be a spurious error from ground reflections. That is one suspect in Becker E10 errors.

If the problem is happening on the ground a simple test is to jury rig a whole new coax cable from the transponder to the antenna and repeat what caused the problem.

I suspect a common cause of the E10 error is coax cables, especially faulty coax connectors. The only time I've seen that it *was* a faulty coax connector. Screw together coax connectors can have more have problems through handling. And corrosion can get into connectors. Much more likely an issue than the ground plan itself or it's connection between the ground plane and its coax connector. Always suspect the connector at the unit as it gets handled/abused most.

It its a rod/ball antenna give the rod a gentle tug, I've seen those broken out and uh pushed back in.

If the tech thinks the Transponder is faulty they should pull it onto their bench and test it there.

Darryl, it's a Becker ATC4401, blade antenna, on the bottom of a DG400(guessing it has some carbon fiber in fuselage). The previous owner reported seeing the E10 a couple of times over three years, he'd recycle the transponder, E10 went away. I see the E10 both on the ground and in the air. Recycling the unit has worked for maybe up to 3 or 4 minutes, than E10 pops back up. The ground plane looks like a laminated square of tin foil, maybe a foot square. The backing plate for the blade antenna looks like it has a ground wire attached under the foil to one of the backing plate screws. The reason I'm very reluctant in sending the unit to Becker in FL for testing & repair is due to previous posts where this has been relatively ineffective. I agree with your comment regarding the Trig Tt22, it looks to be the only one right now worth buying due to the ADS-B out capability. Before I go that route I thought I'd exhaust all reasonable efforts to get the Becker back working.

Thanks for your input!
Steve Cameron

Steve

If it has an adhesive aluminum foil tape type ground plane then it may be more suspect than say a better looking aluminum plate ground plane. I’m not sure by what you mean by “properly grounded�... you don’t want to add additional ground wires /jumpers, what you do want to do is check the condition of the ground plane where it meets the antenna connector and that the outer coax nut is tight and contacting actual aluminum. IIRC the DG 400 fueslage is mostly fiberglas with some carbon but I have no idea about where your transponder antenna is or might be mounted. There are enough gliders of this vintage with really bad transponder antenna instalations in places like the gear doors with undersize and poorly made ground planes.

DG have a TN available for transponder antenna installs, because they live in a closed world other folks including me can’t see what exactly they recommend. I hope it is more like an round aluminum sheet plate, and if it’s over carbon fiber the surface in contact with the ground plane is sanded down to expose carbon fabric.... but follow the TN instructions as close as possible.

I also have no idea how hard it is to reach the antenna, if that needs the engine removed etc. but I would really try a jury rigged new coax test on the ground. And avionics shops may have coax already terminated laying around.m they can use for that.

It’s unclear what technician you are working with, is it’sn actual avionics shop it should be easy for then to exercise your transponder in the bench, worse case they might want to pull out your encoder and wiring harness or make up one to get stuff running on the bench. Some guys who do mobile transponder tests only may not be able to or not want to do this. If it’s a glider repair shop they usually will not have the test equipment to do this. If this is your first glider ownership experience be careful who you ask to work on your glider. Many avionics shops may not be good choices unless they have experience with composite aircraft and hopefully have seen gliders before. Many glider repair shops are not set up to do advanced troubleshooting of avionics. You may need to work with both types of shops to get this resolved or a Trig TT22 installed.

I would be wary of replacing the Transponder and finding the coax or ground plane is faulty. If you do replace with a TT22 that does open up the possibility of installing the transponder body remotely, closer to the antenna which might encourage you to replace that coax anyhow.

The Becker transponder in my DG-300 would frequently give the E10 error. When I changed from my old SLA battery to a LiFePo battery the E10s became a lot less common but still occurred occasionally. If I did get one, I often found mid flight that I could turn on the transponder an hour or so into the flight and it would work fine for the rest of the flight. Mid season last year I gave the connector a serious wiggle and shove into the transponder. Haven't had an E10 ever since. However, every time I turn it on my fingers are crossed.

Larry'

Darryl, I'm going to make a new ground plane and try it with my existing coax & connectors. If no joy I'll run a new coax with connectors & try that, will post a report when done.
Thanks
SC

On Friday, May 11, 2018 at 4:10:14 PM UTC-5, 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

FWIW,
last fall I installed a trig tt22 in a cirrus, used a copper sheet I bought from hobby lobby, .016 thick, If I remember correctly. Also I read somewhere that a round ground plane was undesirable, a square was preferable. I can't seem to find that reference now.
I used copper to easily form it around a glassed in rudder cable guide.

Good Luck,
Scott W.

On Saturday, May 12, 2018 at 9:09:44 AM UTC-7, Scott Williams wrote:
On Friday, May 11, 2018 at 4:10:14 PM UTC-5, 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

FWIW,
last fall I installed a trig tt22 in a cirrus, used a copper sheet I bought from hobby lobby, .016 thick, If I remember correctly. Also I read somewhere that a round ground plane was undesirable, a square was preferable. I can't seem to find that reference now.
I used copper to easily form it around a glassed in rudder cable guide.

Good Luck,
Scott W.

A square ground ground plane is not really more desirable, you want symmetrical antenna performance. The reason for using a non-circular one is if often you could not get an appropriate size circle to fit, and then it might be better to find a different antenna location... but not always possible. Bigger is better and beyond a certain size the shape is not critical, I just don't want people thinking a square or other shape is necessarily more ideal than a circle.

Schempp-Hirth have great installation instructions for many of their gliders including rectangular ground planes, and cutouts for obstructions etc. Again, best to follow those. And they also use copper foil and are careful to ground that to the antenna and use appropriate type of antennas and nice mounting washers for electrical contact etc. (the common rod style antenna with a single mounting nut is not a good choice to mount onto a foil groundplane IMNSHO, they work much better on a solid aluminium plate) . Foil or thin sheets can be a good solution to curved surface and difficult shapes, but heavier plates are great if there is space for them.

Again. most glider manufactures have good technical notes on transponder antenna installs, if there is not one for your glider find one for a similar glider, with similar composite construction and try to follow it reasonably closely.... and sounds like you may have done that for the Cirrus.

---

Back to the original issue, we have no idea what is wrong here, I would be doing the easiest/quickest tests first to try to work out what is faulty.

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'