Is there a Tuner Dr. in the house?

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When I bought the SA-8800 from Web Police a TX-7800 came with it (it's apparent standard partner). I would really like to finally get it running correctly and pull the TX-9100 for small repairs. replacing it with this one. While I can spray it, air it etc, it really needs an alignment and likely more and it's not in my means yet to do that.

Below is a picture of it 'centering' on a station at 96.1 MHz...it's on the ragged right edge actually and peak tuning is always to the left and not stereo, not locked and if either or both lights are lit they are flickering. I need an alignment, among other things. I can get good mono but the tuning is sloppy and I can do all I can but I don't think it's going to be enough.

I think I might have side panels that fit it to match the SA's. It's time to get this tuna out of fishy.

 

[orange]

Okay, it's opened up, beacuse the multivoltage switch fell into the tuner...it's underneath the transformer which is on top of a metal box in turn.

It's getting a more thorough cleaning and I rigged a clean straw to the air can.

Let's see what can be done. I gather getting the box open won't be hard...we'll see.

 

[orange]

I wiped the board carefully with damp cotton swabs (well over a dozen!), Deoxited and turned the the varable capacitor and most of the tuner boards, turned the cap and blew them off with air and solved most of the tuning problems. Now it does need an alignment. No stereo or lock at all but the mono is pretty good. Bleedover and sloppiness mostly GONE. The variable output pot probably needs a spraying but I'm not worried.

Some pictures later, now I need somebody to align ir or maybe more. It's a lot better now.

 

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And I only have to locate TWO screws

(one now-one for the lid)

 

[orange]

HAY!

I posted here a minute ago!

I figured a lot out since yesterday...a lot of my problem comes from the tuner lock reature.

When you grab the knob the PLL lets go and it resumes lock once you let go, The signal goes noisy THEN, altoug you CAN some decent stereo with your paw on the knob...

I can't find any alignment or other info on it on the cheap right this minute, only a schematic and I need the rest of the servicing info.

 

[orange]

EUREKA moment?

A Eureka moment sucks more than a Hoover...
I realized that the locked light never kicks in until you let go of the tuner...SX-1980 feature? I may not have read about the lock here...it was probably PS on TH talking about three SX-1980 restorations he was doing.

I think THAT is what is going on...it can be made to give pretty nice stereo actually...UNTIL YOU LET THE KNOB GO. Once it loks, the sound is messy again and you switch muting/mono on to get a nice clear MONO output.

THAT WAS IT! I forgot to POST it!

 

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...

 

[NavLinear]

Uh-oh! Where have those Q-tips been?

 

[NavLinear]

So it's working now?

 

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Partly!

I've been able to find ONE thing in the schematics on TH, which is the there is a sensor feature much like the on in an SX-1980 ('human sensor') that turns the PLL OFF when the knob is touched and back ON when you let go to lock the signal. THAT WORKS AS I BELIEVE IT SHOULD.

Since MPX isn't turned on until somewhat just BELOW peak tuning...

AND you can get great stereo with your hand on the knob...

AND I know that it DOES probably need alignment...

AND mono is BEAUTIFUL, it locks and fusses NOT...

I suspect alignment/MPX section adjustment or something going bad is the vague yet more focused diagnosis.

The manual I have says NOTHING about this problem or solving it, only schematics.

I don't even have the part number for the multivoltage switch and the Pioneer parts site wasn't a help on that.