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G4BXS
Wed 1st Oct 2014, 21:49
Has anyone got any ideas where my problem might be?

I recently acquired my first Ten Tec. Its an OMNI VI and I have been very pleased with it. The receiver is so clean and I have got a fairly comprehensive set of crystal filters in that work brilliantly.

The problem is that when I first got the radio, when I turned it on it took a few seconds for the audio to start working. There was a pause of several seconds and then a whining noise (starting low and increasing in pitch upwards. After a few seconds the audio would suddenly 'click' and then come alive.

Its now stopped working altogether. The s meter is moving and many of the controls seem to be working yet there's no audio out of the loudspeaker.

The product detector board is fairly straightforward, but I ought to bear in mind that it might have been modified? I'm minded to blame the audio digital processor but I can't be sure.

Had anyone got any ideas where I should start looking?

Thanks in advance.

John G4BXS

G4BXS
Fri 3rd Oct 2014, 21:06
A quick update:

Its now become intermittent. The same low to higher note whining as it kicks in when its warming up but now the periodically disappears whilst the radio is running. You can sometimes hear something faintly in the background and all controls appear to operate normally. Hence the rf stages, the mixers the LO are all working (You can see from the 'S Meter' that you are still tuning across the bands. Band selection all still works.

Studying the circuit I have the audio goes from the product detector and initial audio amplifiers to digital signal processing. I cannot find a reference for this part of the circuit.

Any ideas please?

K7KBN
Sat 4th Oct 2014, 01:00
Try using a set of headphones (turn the audio gain all the way down and then increase it slowly). See if the problem might be in the jack.
Or - try an external speaker in the jack on the rear of the radio. I've seen a lot of closed-circuit jacks get a little bit of corrosion and become intermittent.

No idea as to what that sound is when it's warming up, though. Never had a Ten-Tec.