VM 977 update

[hermitcrab]

Finally got the dial cord and installed it , once again no matter how tight I got it , it would slip , like Greg instead of masking tape on the tuning shaft I used liquid tape and let it dry, that solved that problem , now the next problem is the FM ... it plays but on only one channel..I cleaned the switch and worked it quite a few times but made no difference ... the AM works on both channels , I figure if not the switch it has to be at the MPX output ... the stereo light works , but barely...it is so weak that the filament will just barely glow on the bulb on a strong station....schematic time ...

[William]

From what you were describing before, the chassis looks better than I thought it would. It has a larger PT and the two output transistors look like output transistors. The Philco console that I just worked on had a PT the size of an output transformer and the output transistors looked they should be preamp or tuner transistors. That Philco chassis was really cheap, but I had six speakers and actually did not sound all that bad.

Bill

[hermitcrab]

The dead FM channel fix was easy ... if you look at the pic to the far right IF can at its base is a gold 5mf electrolytic, it was open ... both channels now working as they should, still have to do voltage checks for the MPX the stereo light , is so weak you can see every turn of the filament... was going to align the set... I have every slug adjusting stick there is... except the one this one needs ... the changer will be a bear as it was not treated kindly by its owners...

[electra225]

Might there be another electrolytic cap in the chassis that is causing the issue with the stereo light?

[hermitcrab]

I finished up the chassis and re-installed back into the cabinet , as far as I can tell the stereo light is working correctly all the voltages are there and the regulation transistor is doing it's job ... I guess it does not need to be that bright in the cabinet...I had to resolder all the wires to the changer as they are all hard wired to the chassis , and my messing around with it broke all the wires off ... I measured the output voltage and she peaked at 8 volts per channel... and with a combined speaker impedance of 20 ohms per side , it worked out to be about 3.5 watts per channel ...I also took a shot of the rear showing the speakers

[hermitcrab]

Here is the shot of the rear , for some reason it only took the first picture , now I have to tackle the changer... first thing I do is order a replacement idler wheel ... VM wheels always turn into stone ...

[William]

Elton, are those 12" woofers?

Bill

[hermitcrab]

No sir... 10" with 3 1/2 tweets separated by a 20mf cap which I need to replace

[William]

Thank, it's hard to tell from a photo.

Bill