Batboard

How can I improve the audio RX on my VHF HT-1250 with speaker mic - it sounds bad and there is always a hum when it's RX no matter what CH or Freq

The hum is a bug when using MDC and PL signalling together.

With MDC enabled, the radio uses the MDC/DPL baseband offset instead of the PL offset, and you get a charming hum on the received audio.

The solution is to use Global Tuner to change the MDC/DPL baseband offset frequencies.

Under Utilities/Update Baseband Offset change the value for the MDC/DPL offset to match the appropriate PL value. I've had very good results using 57Hz.

Note that you have to change the offset for all three channel spacings, and click the "update" button after each change, before changing between spacings.

If you want more information, I can forward you a copy of the notice taht Motorola put out on the bug.

Thanks humhead, I too was wondering how I could improve the audio on these radios. I used 115hz and had good results too.