[TheUniversalDave1]

I finally got my 1941 Zenith 8S563 working! It isn't a 16B, but it does sound quite good. I got all my working radios on display in my broom-closet bedroom.

I am well aware of the dangers of a 6X5 rectifier.

[Fred Taylor]

Keep up the good work

[TheUniversalDave1]

Thanks. I still have to fix the tuner on the Zenith - the old belt crumbled. I've got three more Philco's that need a little love.

[klondike98]

[TheUniversalDave1]

While listening to my Zenith, I've been reading up a little more on the 6X5. I'm nervous now. Is there a known drop in replacement for it, or should I just put in two 1N4007 diodes? If I do that, how? I've heard they go across pins 2 and 3, 5 and 7. My Zenith is working right now with a GE Electronic 6X5GT.

[TheUniversalDave1]

Here is my Zenith's 6X5GT. Is the 6X5GT a trustworthy tube, or is it just as bad as its 6X5(G) counterparts?

[Arran]

 As far as I know there is nothing inherently wrong with any 6X5GT, though some will swear by the types with the "X" style plates. If you want to evaluate the risks of using a 6X5 in the Brand Z, the first thing to do is have a look at the schematic for the 8S563, then look up the maximum specs for a 6X5 and compare them. The maximum output voltage for a 6X5 is 370 vdc, at a maximum current rating is 70 ma, with a capacitive input filter, a 5Y3/5Y4/80 is 125 ma. The one you have to look at for the most part is the power output tube since that's the big current hog on the B+ normally, in this case it's a 6AC5, maximum plate voltage 250 vdc, maximum plate current 32 ma.
 I found the Nostalgia Air diagram for this set but the resolution is very grainy so I can't read the voltages on their version of the diagram. If you want to figure out whether the 6X5 might be overstressed, add up the plate and screen grid currents of the tubes by checking the operating voltages on the schematic and then by checking a tube manual to see what the screen and plate current draw is for each tube at a given voltage, or as close to it as you can get. In this case I don't think that you will need to worry about the 6X5 being overloaded, unlike some sets in their lineup it looks like the engineers who designed this model actually consulted a tube manual before designing the power supply, other then using a cheap transformer which is a common issue with all late 1930s and early 40s brand Zs.

Here is a good site to look up tube data, they even carry European and British tube specs:

http://frank.pocnet.net/sheets66.html

Regards
Arran

[TheUniversalDave1]

Thanks. I'll try to do that tomorrow. Since posting the last message, my Zenith started getting VERY ornery and cranky. It started doing some weird popping business and then went dead silent. It got very picky about which way the Wavemagnet was turned and all sorts of other stuff. It was working excellent earlier today. My Philco 16B and my Zenith definitely DO NOT get along. If one works, the other is guaranteed to break!

[TheUniversalDave1]

I got a new dial belt on the Zenith, but now the whole band tuning and volume assembly is mucked up. The copper tubes and rods were bent out of shape before, but they're worse now. The radio makes all sorts of horrible scratchy sounds that weren't they're before. Does anyone know a source for those copper tubes and rods that make up that shaft?

[Arran]

Thanks. I'll try to do that tomorrow. Since posting the last message, my Zenith started getting VERY ornery and cranky. It started doing some weird popping business and then went dead silent. It got very picky about which way the Wavemagnet was turned and all sorts of other stuff. It was working excellent earlier today. My Philco 16B and my Zenith definitely DO NOT get along. If one works, the other is guaranteed to break!

 Has the chassis for the Brand Z been electrically restored yet? If not stop using using it immediately. It sounds like bad capacitors and maybe some resistors are going out along with them.
Regards
Arran