Spectra -- squelch adjust

[TONIC]

Hey folks,

Have an issue I have not seen for awhile.

Spectra with squelch at 15 in software is still opening up at .16 uV.

Problem appears to be on RF board.

Any help would be appreciated.

Thanks,

TONIC

[Will]

Opp's, time to rebuild the RF board. Could be the Command board too, could be the Rec frontend, 'too'. Just switching out boards can get you in trouble, as a problem on one can make the other one useless.

[TONIC]

Will,

Thanks

I'm quite familiar with the wonders of the Spectra.

It is a RF board issue -- maybe a part out of tolerance.

Typically -- at max ( 15 ) they will open around .3uV.

This one is just a little too enthusiastic.

Time to start playing with the squelch ckt outside U301 I guess.

Thanks

TONIC

[Will]

Tonic,

The noise goes from the RF board up thru the Audio IC on the Command board where the noise gain is set by the microprocessor, like a 'softpot', then returns to the RF board for the accual squelch detector circuit.

Sounds like not enough noise or lack of noise gain in the Command board.

[TONIC]

Will,

That was looked at.

The issue is the level coming from the RF board.

It is not the same as a known good board with normal settings and squelch behavior.

The RF board was changed first and the problem cleared.

Now I am looking at the parts off of U301 to determine why the difference. U301 is good by the way.

Thanks again for the feedback. I let you know what I find.

TONIC

[VE3TUH]

I would like to hear what you find, I have the exact same problem on one of my Spectra's, it can be a pain when scanning as the radio unsquelches very easily. Was wondering if as these radios age they will start to exibit common issues like this.

Thanks,

Randy

[Cowthief]

Hello.

The spectra has real crap for caps!.
The things WILL leak, and damage traces on the board if not replaced.