Messages

1

General discussion forum / Re: Remoterig 1258 stopped transmitting

« on: 2016-09-12, 19:36:11 »

When I said I checked the jumpers multiple times, I guess I meant the installed jumpers.  The 8V jumper was missing - with it in, I now have audio from the microphone.  But I am stumped - how has it worked for the last three years?

Next issue - DTMF works with microphone connected to radio - but not with it connected to the RRC.  Is this normal?

Thanks for all the help.

Bob
W0BR

2

General discussion forum / Re: Remoterig 1258 stopped transmitting

« on: 2016-09-10, 20:33:43 »

I have relocated the system to my home. (originally installed in the county EOC) I set up a router to use the same settings as before.  I get the same results - all functions work - but no TX audio.  Plugged directly into the radio, the microphone audio is fine.  I have checked cables and jumpers multiple times by now.

I observe that by probing around in the RRC-control unit, I can induce hum on the TX audio.  Seems to be the loudest at pin2 of the Codec.  I could make it even louder by increasing the Codec input gain from 13 to 63 - but still no audio from the microphone.  Probing the microphone input, it gives very low level hum. 

I conclude from this the problem is either an open series component or something shunting the microphone audio to ground.  Is there someplace else I should be looking?

All I see in the manual is an abbreviated schematic of the microphone input / bias circuit - can i get a schematic of the rest of the microphone audio path?

Thanks,
Bob
W0BR

3

General discussion forum / Re: Remoterig 1258 stopped transmitting

« on: 2016-08-29, 14:56:09 »

The radio is Kenwood TM-D710.  It had been working fine earlier in the day when it failed.  Nothing was intentionally changed in the settings. 

Fundamental question - can a networking issue cause only the TX audio to fail?  (RX audio and control functions are okay)

73,
Bob
W0BR

4

General discussion forum / Re: Remoterig 1258 stopped transmitting

« on: 2016-08-26, 22:40:04 »

I am now investigating the problem originally brought up by bobsingle.

1.  I have not looked at the status of each side.  RX audio, frequency control and PTT are working properly - shouldn't this indicate proper operation of the "pipe" and router? 

2.  We confirmed the problem today.  We tried the following steps:
a.  plugged in a second microphone (and control head) - still no TX audio
b.  opened both units and confirmed red straps with ohmmeter - checked continuity from input connector - all okay.
c.  plugged in microphone and control head directly into radio - TX audio okay.
d.  Interesting observation - thinking it may be an intermittent connection, we tapped on the circuit board - heard what sounds like microphonics on the TX audio (listening on HT).  Also - touching the MIC wiring on the jumpers with tweezers gave low level hum on the TX audio.

Any suggestions for what to try next?

Thanks,
Bob W0BR