Anyone has experience installing KRT2 radio in single seatersailplane ?

Hi guys,

I'm trying to get my new KRT2 radion to function. I bought an adapter with it to simply plug in my old ATR720 wiring. All seemed well, except there was no sound coming off the speakers on receive (or when opening up squelch). We then tried using the original wiring loom, rewiring everything. Same result.
Then we grounded pin12 (as per manual - manual intercom not needed), and finally there is some sound coming off the speakers, but it is distorted so much, it is impossible to hear what was being transmitted. Also, when volume is set to lowest setting and nothing is being received, there is a high pitch sound coming from the speakers. When volume is turned up, high pitch turns into random noise with much less pitch.

Settings are as per user manual for sailplane:
VOX: Set to VOX 10 (turn off).
TXm: Set to TXm**.
EXT: Set to EXT 00 (turn off).
MIC: Set to MIC-L to Level 11.

Any suggestions to get the radio working would be highly appreciated.

Thanks,
Tadej

On Thu, 17 Jul 2014 14:20:43 -0700, cruisah wrote:

Hi guys,

I'm trying to get my new KRT2 radion to function. I bought an adapter
with it to simply plug in my old ATR720 wiring. All seemed well, except
there was no sound coming off the speakers on receive (or when opening
up squelch). We then tried using the original wiring loom, rewiring
everything. Same result.

Did you use your old D-15 connector or the new one that came with the
radio?

Which version of the manual did you get?
Look at the wiring diagram for the single seat harness. Do the schematic
or the drawing of the D-15 connector show pins 1 and 9 as linked together
or not?


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Hi Martin,

both - the supplied manual on the CD (dont know the version, I have the CD in the workshop) and the latest downloaded version (9.7) show pins 1 and 9 as NOT linked together.

First we tried using the old ATR720 wiring with KRT2-ATR720 adapter that I ordered with the radio, but that didnt work. Then we used the new D15 connector and wiring that came with KRT2, but we got the same result - no speaker output. Only when we grounded pin 12 we got speaker output (pitching and squeeling/schreeching when not receiving and unrecognizable voice when receiving). Now we're stuck again.

Thanks for your help!

Cheers,
Tadej

On Fri, 18 Jul 2014 00:45:36 -0700, cruisah wrote:

Hi Martin,

both - the supplied manual on the CD (dont know the version, I have the
CD in the workshop) and the latest downloaded version (9.7) show pins 1
and 9 as NOT linked together.

OK, that's what I thought: the manual you have is wrong. The latest
version has been corrected. Pins 1 and 9 should be connected. The D-15
that came with my KRT2 has a tiny double sided PCB inside it with all
pins soldered to lands on the PCB, but this is not mentioned at all in my
manual. The PCB is soldered in so that pins 1 & 9 (ground) and 8 & 15
(positive) are connected via the PCB. The other pins are soldered to the
PCB but none of these are connected together.

First we tried using the old ATR720 wiring with KRT2-ATR720 adapter
that I ordered with the radio, but that didnt work. Then we used the new
D15 connector and wiring that came with KRT2, but we got the same result
- no speaker output. Only when we grounded pin 12 we got speaker output
(pitching and squeeling/schreeching when not receiving and
unrecognizable voice when receiving). Now we're stuck again.

My experience is a bit different to yours.

For starters I wasn't offered an adapter and so didn't use one

When I got the KRT2 I used my ATR-500's wiring harness which I adapted by
moving wires around as needed on its D-15 and adding jumpers to ground
pins for the intercom etc. The result, when I put it in the glider was
that reception was perfect, the mic was recognised (the audio bar jiggled
in response to mic input), but it only transmitted unmodulated carrier
wave. So it got sent back to Dittel via the UK agent and an internal
fault was found and repaired under warranty. Good, no quibble service.

In the meantime I noticed that my harness had pins 1 and 9 connected (as
they were for the ATR-500) but NOT as they appeared in the KRT2 manual,
and separated them.

When the radio came back it did the same as before BUT in the meantime
I'd looked inside the cover on the Dittel-supplied D-15, found the tiny
PCB and buzz-tested it, so I knew that pins 1 and 9 were connected by the
PCB. So, I soldered a jumper between them on the D-15 in my harness and
this time the radio worked perfectly and has continued to do so.

At this point I had a discussion with the agent because I wanted Dittel
to change the manual: if/when these radios get sold on in a few years
time there's a good chance that the D-15 would not go with it and the
manual as it stood would be no use at all. I thought it should say that
the supplied D-15 contained a useful PCB and that the wiring diagrams
should be changed to show that pins 1 and 9 must be connected. It turned
out that the agent (John Delafield) already knew about this wiring
discrepancy, agreed with me and was already talking to Dittel about it.

I didn't have any of the noise problems you mention, but quite possibly
there's a difference between the ATR720 and ATR-500 pinouts that could
affect that.

Apologies for this being a bit long-winded, but I've included possibly
excessive detail in case the background is is useful to you.

Would I recommend the KRT2? Yes. Now the problems are sorted its a good
radio and I'm finding its ability to monitor the standby channel
alongside the selected channel is a very useful feature.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Hi Martin,

thank you for exhaustive answer. Luckily, KRT2's are now being produced and serviced by local company - LX Navigation - and I talked to their technician today. He said that pins 1 and 9 must be separated, because now with the newer version the GND is soldered to the housing of the D15 connector. I bought my KRT2 3 months ago, and also there is no PCB inside the D15 connector on the wiring.
Anyway, tehnician said he is almost positive that its the faulty chip on audio exit and that it can be repaired. I checked with Walter Ditter to see if this would in any way void the warranty and was given a green light to have it checked/repaired by LX Navigation. So on Monday I'm taking it there to have it checked out/fixed.

Thanks again,
Tadej

On Fri, 18 Jul 2014 08:36:33 -0700, cruisah wrote:

thank you for exhaustive answer. Luckily, KRT2's are now being produced
and serviced by local company - LX Navigation - and I talked to their
technician today. He said that pins 1 and 9 must be separated, because
now with the newer version the GND is soldered to the housing of the D15
connector. I bought my KRT2 3 months ago, and also there is no PCB
inside the D15 connector on the wiring.

I bought mine in mid-December 2013.

My manual specifies that Battery minus must be soldered to pin 1 and the
D-15 housing and nothing else. The mic cable shield is connected to pins
6, 9 and 12 for a single seat glider. However, in my radio that appears
to leave 6,9,12 and the mic shield floating. Presumably that is why the
PCB in the plug links pins 1 and 9. From what you say the internal wiring
has been revised since mine was made.

Anyway, tehnician said he is almost positive that its the faulty chip on
audio exit and that it can be repaired. I checked with Walter Ditter to
see if this would in any way void the warranty and was given a green
light to have it checked/repaired by LX Navigation. So on Monday I'm
taking it there to have it checked out/fixed.

Good. I trust that will fix it for you.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |