My $30 800 T

Theophilus Punoval

The Queen says it's OK...
I just picked up an 800T in good cosmetic shape for $30. I told the seller it was worth more than that - I may be an obnoxious wiseguy but I'm an HONEST obnoxious wiseguy - and he said he didn't care.

It has a couple of issues. The dial light is as dead as Julius Caesar and while the tuning meter shows signal. The "Stereo Beacon" and "Muting" are also out. AM gives sound but I don't get any output on FM unless I crank the volume knob. Then I get low volume.

This receiver came out of years of unheated storage and needs a thorough cleaning. Maybe that will clear up the FM thing.

Are the dial, Stereo Beacon (red) and Mute (green) lamps readily available or are they gone from this world like the snows of years gone by?

I'm wondering if anyone has had this issue and can give me suggestions short of taking it in for service. I plan on doing that but hope to clear up any minor problems before I bring it to the shop so I'll have a clearer idea of what's actually wrong beside crud on switches.
 
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The Stereo Beacon and Mute are directly tied in to FM reception. You can test the light bulbs with a meter. They are wheat bulb lamps (I don't have the manual in front of me right now. The Dial lamps are the 8V fuse lamps. TRY DGWOJO.com for the lamps. The FM is not the conventional Tuning capacitor for FM. It's whats called a varactor circuit. AM is a conventional Tuning capacitor, it's in a tightly sealed box, do not open. You can spray CDC QD Electronics Cleaner or Contact Cleaner on the varactor section and work them to see if it helps the tuning. NO DEOXIT on the varactors. Otherwise everything else switch and pot wise can get the D-Oxit treatment.

It's possible there is a power supply problem on the board. They tended to run hot and burned components on the P.S. board. As it's on the bottom of the unit and turned upside down it collects heat.

Get the manual. It's available on the AK DATABASE. Look for the 500-TX manual. The 800-T is the export/multi voltage version and uses the SAME MANUAL. Other than the front panel and the transformer/powersupply they are identical. It was FISHER's Solid State top of the Line Receiver for 1969-1972 or so. I have a 500-TX and an 800-C. Pretty much equal but the 500-TX is a bit brighter in the highs. Owners manual, Service Manual and a Service Bulletin are here Do the procedure on the Service Bulletin 1st. That may help the problem.

I'd rebuild the Power supply....new caps, new diodes, resistors, and if they are bad the transistors on the board. Be prepared to have problems finding a replacement the transistor. Unless you have successive manuals for xreferencing them it'll be hard.

Check the INPUT voltages on the FM BOARDS and compare them to the schematics. If they are low it comes back to the power supply.


Larry
 
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