[pkingco]

Hi all,

I am getting near the end of my 38-10 re-cap and repair, and noticed a charred receptacle at one pin location on the rectifier tube (5Y4G) socket. Being a rank beginner and knowing nothing about these tubes, I'm looking for information on 1) whether all 8 pins on the tube are used, and 2) if this foggy tube is an indication of a short or bad tube? I'm attaching the tube schematic and a photo of the charred pin position and corresponding pin, marked with my tool. Thanks for your help.

                   

[KCMike]

Hello, The tube looks like it went to air >lost vacuum< yes it would be bad. The tube socket will need to be replaced. It uses a 8 pin octal socket.
4 of the pins are used on the rectifier tube. Pins 3&5 are the plates and 7&8 are the filaments.

[Radioroslyn]

Time for a new socket. It's burnt where there is hv ac. Would replace w/a molded one rather than the cheap wafer job. Not sure abt the tube the cloudiness maybe an issue. To be on the safe side wouldn't hurt to replace.

[Stall-U-Rated]

Yep, the getter be gone on that tube (silver at bottom) ... Time for a replacement, as well as the socket..

Steve

[pkingco]

Ok, thanks all for the input! Now to find a socket....

[Chas]

Be sure to specify the mounting screw hole spacing. The wrong socket may require drilling, not cool...

Stay away from China sockets if you can, rumor control has it the tension on the pins is rather weak... Or YMMV...

Test the power transformer before going too far. Tape up the filament and high voltage leads, be sure there is no shorts in the rest of the filament circuits. Power the chassis and wait for 1/2 hour. If no crackling noises followed by smoke and heating after half an hour the transformer is O.K.

Chas