[flatheadjr]

So adding the speaker gave a positive result. Now I have nearly the right voltages at the output tube. These early tubes still confuse me on their numbering. However starting at #2 pin if I'm correct I was at about 310, and the next was at 325, are these to high? I had one with a negative voltage and the last pin no voltage. What's my next move?

[Raleigh]

I pulled a schematic from Nostalgia Air and also a pin-out for the 42 tube from here: https://frank.pocnet.net/, so I wouldn't be guessing any more. I see I guessed wrong about a few things I wrote before. Sorry.

I can't tell from the schematic whether those voltages are right or not, but from the tube data sheet, they are right at the max, maybe because the field coil has less resistance than it should. The voltage at pin 3 should be higher than pin 2, which is what you have.

Next, check the voltages on all the other tubes. See if there is anything else in the service date that would give you clues to what the voltages and/or resistances should be. Sometimes there is a table of voltages or resistances. I don't have time right now to look it over, but I'll check back tonight.

[flatheadjr]

My service data sheet says plate volts @ 300 and screen grid volts @ 310 no cathode voltage. If you go down the chart on the tube page depending on what that tube is being used for the voltage can go to 350. My schematic ohms out the field coil to 660 ohms, my meter read around 675 ohms I may have typed the wrong number before.

[Radioroslyn]

Check your PM box.

Terry

[flatheadjr]

Terry so I measured the wrong point on the shadow meter, found the right point and it measures 815 ohms, so I guess it probably is good? So I need to just reinstall that 4k ohm resistor, but I may have a problem with my electrolytics so I'll have to figure that out Monday.

[Radioroslyn]

The older style sm have a resistance around 900 ohms later ones are up to about 1200 ohms. So you should be ok. Do you find any HV at the sm?? Or at both ends of the 4k resistor?? Should have at both places. Methinks that the electrolytics are ok as the HV is good at the output stage. Seems like some thing is open in the HV line going over the IF amp stages.

Terry

[flatheadjr]

It seems that the electrolytics are hooked up correctly as I am not having a problem there. The big problem is that there is no 4k resistor. I know one end hooks to the shadow meter, but if I hook up the other end to pin 2 on the type 42 tube the speaker crackles and makes lots of the wrong noise. I don't know where this 4k resistor goes, supposedly is number 46 on the schematic.

[Radioroslyn]

Goes to pin 3 the second grid or screen grid of the 42 tube.

Terry

[flatheadjr]

Check your PM box, I need to send a high def photo of the underside. If I hook it up to pin 3 of the 42 tube that also connects with electrolytic cap as well. I may somehow have a bad schematic drawing.

[flatheadjr]

Terry, just wanted to check and see if you got that photo of the chassis let me know if you can see what is going on there.

[Radioroslyn]

Update talked to flthdjr on the fone and did some troubleshooting to find that #46 (4000 ohm resistor) was missing. Had no B+ to the mixer or IF amp tubes. He install a suitable replacement and it's playing.

Terry

[sam]

Expert 

[klondike98]

Good job guys!!!

[flatheadjr]

So the radio is working pretty good, I've replaced the rest of the wax paper caps, but a couple more things may need to be addressed. I noticed the large resistors get fairly hot and that they are also out of tolerance so I know I need to replace those. The shadow meter, all I get is a black view with a little light behind it, it does doesn't appear to be working correctly. On the low end of the band after a while it fades out but the upper part of the band on AM stays just fine. All the small resistors seem to be fine and very close to tolerance so I'm probably going to leave those for now. What should I look for on the shadow meter?

[Radioroslyn]

> What should I look for on the shadow meter? 
Well there is bunch of stuff. The meter it self the vane could be stuck or broken or the permanent magnet may need to be remagnetized. The good thing here is that we know that the coil is good.

On the chassis I'd check the voltages at the tube against the diagram. They will probably read a little high because of your modern meter. This is ok as long everything you measure comes up a little higher maybe 10-15 percent. Voltages at the plate or screen grid that are too low, control grid voltages are too negative, or cathode voltages that high will affect the gain of the tubes. The ones to check are the mixer, IF amps, and detector. This in turn will affect the current flow though the meter. Check resistors that are 1meg or higher. These are mostly found in the radio's avc (automatic volume control) circuit. They affect the gain. Weak tubes in these positions can be a problem too. RF and IF alignment will affect also.
http://www.philcorepairbench.com/tips/svctip01.htm

Terry
If life gives you melons you may be lisdexic