[dkoczur]

10 UF electrolytic (no.75 on Model 16B rider's schematic)is not marked with positive and negative terminals. Which end is the positive terminal? Does it go to ground or to the negative terminals of the two 8 UF electrolytics?

[radiodale]

Found correct schematic. Positive goes to ground. CT most negative point.

[dkoczur]

OK. I connected a 10 MFD 50 V electrolytic with the positive to ground and the negative to the center tap. It blew up twice. The first time I had all the tubes installed. The second time i did not have the 80 installed. The first time i had 115 V ac input applied. The second time I only got to about 70 Volts input on a variac. Don't know what to do next. What should I be looking at?

[morzh]

You should be looking at shorts in the rectifier tube's socket, namely from High voltage transformer output to the heater of the same tube.

Another possibility - a short between the High voltage and heater windings inside the transformer. Check with ohmmeter with power off.

PS. Somewhere there likely is a short. Before turning the radio on, with or without tubes, you should check for load/etc shorts first.

[dkoczur]

You were absolutely right. There was a short on the rectifier socket.to the filament. Thanks for the help and the guidance for future restorations.