I'm overhauling my 1941 Zenith this weekend
 

I'm going to the radio club this weekend and I'm going to replace as many capacitors as I can. I'd also like to do away with the 6X5GT rectifier. I've asked how to do this before, but I guess I forgot or something. I know you can install two 1N4007 diodes, I just don't know where they go. If somebody could fill me in, that would be super helpful. The radio plays good, but the chassis does need some help. All the rubber wiring is falling apart, it needs a total recap, (I put in two and an electrolytic), and it needs a tuner belt.

Here is the inside.

Googling 6x5 tube data and searching wikipedia for diode should yield enough data for you to figure it out.
https://frank.pocnet.net/sheets/127/6/6X5.pdf
https://en.wikipedia.org/wiki/Diode

If you want to keep the original tube in and lit then remove plate and cathode leads from the socket and mount a terminal strip for those leads and the diodes.

That's what I had in mind. I want to keep an original Zenith 6X5G in there and have the diodes in the chassis. Somebody told me to remove the two plate wires and one cathode wire from the tube socket and wire them together in a Y shape. I think one lead of both diodes connects to the cathode wire and the other two leads to the plate wires.

The cathodes or the marked ends of the diodes go the cathode wire from the tube socket.
The newer GT type 6X5 is generally reliable. I, personally like a tube rectifier, but I generally only turn on my tube radios to show how well they work. :thmbsp:

Okay, I think I understand now. I've heard of people putting a resistor in the mix too. I use my tube radios almost everyday.

With the Si diodes, the B+ will come up instantly. So you need to be sure the filter caps are rated for the surge voltage.

And also, how well will the old power transformer hold up with increased peak current surges? Frankly, I would not replace the tube with ss diodes, but would add a small light bulb in series with each plate lead as a quick blow fuse. I think Zenith at the time recommended #47 bulbs.

jr

here is the old thread where that is recommended:
http://www.videokarma.org/showthread.php?t=265632

.

Well I was going to replace the filter caps with 450 volt units anyway. Unless the surge is more than that, in which case I'll go up to 600 or 1000.

You could also use one light bulb or a small fuse (say 250mA) in series with the ground connection (centre tap) of the B+ winding.

Or make a socket adapter for a 6X4 or say a 6CA4

Hi, Here is another way to solve the 6X5 problem and keep the tube. If there is room above or below the chassis add a small transformer with a 6.3 volt 1 amp secondary and wire the 6X5 heater to the new transformer, do not ground the heater of the tube. Connect the cathode to one of the heater pins, that way you do not have the break down issues of that tube. I do that with all of my old Zenith radios with transformers and 6X5 or equ. tubes. hope this helps. All the best,Tom

I'm won't be getting a new transformer. I'll probably just use a terminal strip to affix those two diodes on the underside of the chassis where you can use any old 6X5, and it will still light, but it won't be doing any rectifying.

Here's what I've come up with. Your thoughts?

I will do some research for you. I just got done restoring a Zenith radio similar to that style for titan1A on this site. His is a 7S232 chassis. He (Rick titan1A) found a place to order a solid state plug in tube to replace the 6X5, and also a belt material to use to replace the tuning belt, without having to disassemble the entire tuning mechanism. I will do some research and see if I can come up as to where I ordered this items from. I don't suggest using a 6X5, as if the tube shorts heater to cathode it most likely will take out the power transformer. Wiring diodes should work out fine also, but yes, you will need some type of resistor in series to prevent the surge and also to drop some excess voltage. Personally I don't think light bulbs are a good choice.

Yes, my No. 1 concern with this radio is getting rid of the 6X5. I don't hear any objection to my drawing, so it looks like it's going to happen. Probably next Saturday. Not tomorrow since I'm doing tubes and capacitors tomorrow.