Mark 12D Problem???

You have just made your first unauthorized aircraft repair. CONGRATULATIONS
and welcome to the sororfraternity.

{;-)

Jim



Back soon with results from the test flight...

Best Regards,
Todd

Arrgghhhhhh!!! :-(

I took a 45 minute flight to Willows this morning, for breakfast...
The radio worked like a charm all the way there... I took off out of
Willows, and 5 minutes into the flight (while monitoring Oakland
Center), I noticed the reception was getting scratchy, then... No
transmit, no reception, no side-tone while attempting to transmit. I
tried applying pressure to the radio to make sure it was seated
properly and even tried wiggling it a bit while applying pressure,
but... nothing!

However, about 5 miles out from Cameron Park airport the radio worked
for about a minute and enabled me to make a down-wind call. Then...
the same thing, no transmit, no receive, no side-tone while
transmitting! :-(

I think I confirmed (once on the ground at Cameron Park) that I can
plug my headset into the plane jacks and by-pass the intercomm, so
that's what I will try next, as well as throwing in a TKM that my
mechanic says I can try...

It sure seems like a vibration or heat issue??? Once on the ground and
the plane shut-down and secured, I plugged the headsets back in to the
intercomm and the radio worked like a charm. That would confirm the
several hour bench check done by the avionics shop. Something is
happening in flight... Any thoughts?

I couldn't get anything off my intercomm to provide a make/model. I
had my friend take a digital pic of the panel, so I should be getting
that soon, if that will help???

Todd

I recently had a problem at not transmitting; no sidetone. however I was
putting out a carrier. I corrected all the obvious problems that have
been mentioned and there were a couple of the finger contacts in the
tray not correct. But, in the end I returned it to Narco. They found
several problems one of which would relate to my problem of no sidetone
and no transmission. I got it back in fine condition for that problem. I
did develop another problem that the audio will not always break squelch
even when the volume knob is pulled out. I can 'solve' the problem by
turning up the volume until I hear the background sound (the audio pops
back as normal) and then turn it down and push it back in. The audio may
work the rest of the flight. I was in the habit of every few minutes of
pulling out the volumn knob to be sure it is still working. I do not
want to miss an ATC call. I contacted Narco and they will fix it under
my repair warranty. Otherwise, both of my MK12Ds have been good. The
other radio is needing a new display and may be sent to them during the
next annual and when I am satisfied that this radio is working.

Oh, to have the money to redo everything with new.


Regards, Ross
C-172F 180HP
KSWI


three-eight-hotel wrote:
Arrgghhhhhh!!! :-(

I took a 45 minute flight to Willows this morning, for breakfast...
The radio worked like a charm all the way there... I took off out of
Willows, and 5 minutes into the flight (while monitoring Oakland
Center), I noticed the reception was getting scratchy, then... No
transmit, no reception, no side-tone while attempting to transmit. I
tried applying pressure to the radio to make sure it was seated
properly and even tried wiggling it a bit while applying pressure,
but... nothing!

However, about 5 miles out from Cameron Park airport the radio worked
for about a minute and enabled me to make a down-wind call. Then...
the same thing, no transmit, no receive, no side-tone while
transmitting! :-(

I think I confirmed (once on the ground at Cameron Park) that I can
plug my headset into the plane jacks and by-pass the intercomm, so
that's what I will try next, as well as throwing in a TKM that my
mechanic says I can try...

It sure seems like a vibration or heat issue??? Once on the ground and
the plane shut-down and secured, I plugged the headsets back in to the
intercomm and the radio worked like a charm. That would confirm the
several hour bench check done by the avionics shop. Something is
happening in flight... Any thoughts?

I couldn't get anything off my intercomm to provide a make/model. I
had my friend take a digital pic of the panel, so I should be getting
that soon, if that will help???

Todd

yeah... I keep thinking (man, if I just had 10 or 15k laying around,
how I could make some nice improvements). I do like the MK12D
though... It's a nice looking radio and worked very well until this
bout of issues I've been recently having.

I just wish I could isolate the problem directly to the radio! I think
we are going to throw it in one more airplane and put that TKM in mine
and see what plays out...

Thanks for your response!

Best Regards,
Todd

One of the trouble shooting things I did what to swap radios in the two
trays. The problem I had followed the radio, so I knew it was a radio
problem.


Regards, Ross
C-172F 180HP
KSWI


three-eight-hotel wrote:
yeah... I keep thinking (man, if I just had 10 or 15k laying around,
how I could make some nice improvements). I do like the MK12D
though... It's a nice looking radio and worked very well until this
bout of issues I've been recently having.

I just wish I could isolate the problem directly to the radio! I think
we are going to throw it in one more airplane and put that TKM in mine
and see what plays out...

Thanks for your response!

Best Regards,
Todd