DITTEL KRT2 transceiver setup

Did anyone experience problems with DITTEL KRT2 XCVR installation and
MIC/INTERCOM setup in motorized two-seaters?

Willy

On Tue, 01 Jul 2014 14:39:19 +0200, Willy VINKEN wrote:

Did anyone experience problems with DITTEL KRT2 XCVR installation and
MIC/INTERCOM setup in motorized two-seaters?

No, but I had a wiring problem with mine in a single seater. If you've
used the D-15 connector that Dittel supply with a tiny circuit board
inside it you'll be fine, but if you use a self-sourced D-15 and wire it
up using any but the very latest manual you may find that it receives
just fine but will only transmit unmodulated carrier wave even though you
can see that mic input affects the level bar in the bottom left of the
display during normal operation.

The issue is with the manual version I received, which carries the IDs
Doc-Nr DE-3000-800100e,
Revision 9.4
P/N 100-(0001)-(060)

This version of the manual shows pins 1 and 9 as not linked. However, if
you test the PCB in the supplied D-15 connector with a multimeter or
continuity tester you'll see that these pins are connected by the PCB.

The radio works correctly if these pins are connected and shows the
symptoms I described above if they are not connected.

I don't know if this would also affect intercom operation, but as pin 9
is labelled 'Mic ground' that would seem quite likely.


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

On Tue, 1 Jul 2014 16:20:35 +0000 (UTC), Martin Gregorie
wrote:

On Tue, 01 Jul 2014 14:39:19 +0200, Willy VINKEN wrote:

Did anyone experience problems with DITTEL KRT2 XCVR installation and
MIC/INTERCOM setup in motorized two-seaters?

No, but I had a wiring problem with mine in a single seater. If you've
used the D-15 connector that Dittel supply with a tiny circuit board
inside it you'll be fine, but if you use a self-sourced D-15 and wire it
up using any but the very latest manual you may find that it receives
just fine but will only transmit unmodulated carrier wave even though you
can see that mic input affects the level bar in the bottom left of the
display during normal operation.

The issue is with the manual version I received, which carries the IDs
Doc-Nr DE-3000-800100e,
Revision 9.4
P/N 100-(0001)-(060)

This version of the manual shows pins 1 and 9 as not linked. However, if
you test the PCB in the supplied D-15 connector with a multimeter or
continuity tester you'll see that these pins are connected by the PCB.

The radio works correctly if these pins are connected and shows the
symptoms I described above if they are not connected.

I don't know if this would also affect intercom operation, but as pin 9
is labelled 'Mic ground' that would seem quite likely.


OK Martin. I used the tiny circuit board in the DB-15 connector.
But I only discovered today that there is a 9.7 version of the manual.
Besides, the instructions in the 9.5 english version didn't seem
obvious at times, compared to the german 9.4.
Also, I noticed a couple of errors with MIC-switch wiring in the
6.8.3.1 Full Connection diagram.

Both gooseneck DYN mics gave 90% AM modulation with my previous
BECKER AR-3201.
With the KRT2, the modulation lays well beyond an acceptable level.
On MIC-setup, when AUTO MIC-detection is selected, the 'MIC: dyn/std'
display answer seems quite unstable.

Then, I don't understand clearly the function of the Manual Intercom
Switch, which is to be used when the cockpit noise level is
incompatible with VOX operation. And why is there a 50 cm cable
restriction to it? Which also means that the rear seat pilot cannot
activate it….

Willy -ON5WV- ASH25E - D-KBAL

On Wed, 02 Jul 2014 00:12:49 +0200, Willy VINKEN wrote:

Both gooseneck DYN mics gave 90% AM modulation with my previous BECKER
AR-3201.
With the KRT2, the modulation lays well beyond an acceptable level. On
MIC-setup, when AUTO MIC-detection is selected, the 'MIC: dyn/std'
display answer seems quite unstable.

I can't help there. My mic (a Monacor DMG-400) is showing consistently as
'std' on the AUTO setting. I haven't had any complaints about the
transmission quality so far.


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

On Tue, 1 Jul 2014 22:54:17 +0000 (UTC), Martin Gregorie
wrote:

On Wed, 02 Jul 2014 00:12:49 +0200, Willy VINKEN wrote:

Both gooseneck DYN mics gave 90% AM modulation with my previous BECKER
AR-3201.
With the KRT2, the modulation lays well beyond an acceptable level. On
MIC-setup, when AUTO MIC-detection is selected, the 'MIC: dyn/std'
display answer seems quite unstable.

I can't help there. My mic (a Monacor DMG-400) is showing consistently as
'std' on the AUTO setting. I haven't had any complaints about the
transmission quality so far.

As far as I know, your Monacor mic is dynamic, not standard.
Which would confirm that the AUTO detection (display at least) is not
reliable, even if it interfaces correctly with the XCVR.
I wonder on what basis they detect it? Resistance, impedance?
All this is a bit confusing. Over the years, I got used to
generations of DITTEL radios with proverbial clear manuals.
That was before the microcontrollers and the sometimes 'fuzzy logic'
of firmware ;-) .

Willy -ON5WV- ASH25E - D-KBAL