The AM Forum

I got one of these from a friend and put a 6L6 in it. I adjusted the line voltage so the meter works. The tube filament lights but no meter movement on this known good tube. I then removed the tube and took voltage measurements which were there except no plate voltage when P4 is pushed. I assume this means the 83 tube is bad. I sprung for the solid state replacement and await its arrival. Sound like that was the issue? Thanks in advance.


                                                                   Earl

Never assume anything. The 533, if I remember correctly, has two rectifiers, 83 and 5Y3. I would have taken a VOM and see if there's any DC voltage coming off either tube. I would also check the resistors to make sure none have opened up or changed value drastically. Having some spare rectifiers around helps to determine if the installed tube(s) are bad or weak. Sometimes it's a simple as a tube replacement; sometimes it's a little more involved. The 533 came out around 1947 so you have a tester that has experienced roughly 64 years of component aging.

 Hi,


   was going through a similar scenerio with a precision 10-12.
A 6AU6 tested ok but a 5U4 in a diff socket didnt get Fil.

  A lot of switches in there. You may want to try a diff.
tube/socket combination. The B+ is switched around as well
as all the other stuff.

GL

/Dan

I sure gaffed by using "Assume" - I read a primer that says the plate voltage comes form the 83 and I also tried may tubes which all lit and warmed up fine with all the other voltages besides the plate on the proper pins. I will follow up when i receive the SS 83 replacement. Thanks all for your help.


                                                            Earl Thomas