01-02-2019, 01:46 AM
Bob,
Thanks for your welcome and link to the more readable schematic
I was able to remove the chassis. 2 knobs and 2 screws. The power knob gave me fits, turns out's pretty gunked up.
Here is a pic of the bottom. I was surprised at the lack of dust considering there's no back piece. I've never cleaned the inside.
After reading Ron's thread on the rubber wiring, I decided to take a much closer look at all the wiring and, yeah, made my heart sink a bit. I'm surprised I didn't blow the thing up when I turned it on. Things touching things where they probably shouldn't be. Even more what I see is a lot of reddish buildup around all the solder points on the tube connections. As well, the soldering all over seems to be a bit heavy.
I think this is going to be a bigger undertaking than I thought. No worries, I enjoy a good challenge. Replacing the caps might be short term to see if things are working. But I think that alone isn't going to be enough long term. Wiring and other things will need to be replaced as well. Why not just do it all at once?
Phil Nelson's beginner site was very informative. His knowledge of capacitor types for old radios was very insightful. You can see from the pics that there are a lot of old ones that are not very reliable and should just be replaced. I am looking into some more modern ones here: https://www.justradios.com
At this point I'm thinking of starting by replacing the capacitors and see if that gets the radio working properly. No point in re-wiring it without knowing what the root causes are? Would that make sense?
Some questions on the capacitors I am seeing:
The electrolytic one is rated mfd 20/20 on the schematic, but I don't see the voltage. The blue one in there now is VDC150. Without the schematic stating otherwise do I assume that is the correct voltage? I know that I can go higher in voltage, but I'm having a hard time finding one rated 20/20 at 150vdc.
Can the one in the middle that has the coil around it be replaced with a modern cap that doesn't have the coil?
Given all that, I'm looking for some thoughts/comments on what I've observed and what I might have missed.
Thanks again for any help!
John
Thanks for your welcome and link to the more readable schematic
I was able to remove the chassis. 2 knobs and 2 screws. The power knob gave me fits, turns out's pretty gunked up.
Here is a pic of the bottom. I was surprised at the lack of dust considering there's no back piece. I've never cleaned the inside.
After reading Ron's thread on the rubber wiring, I decided to take a much closer look at all the wiring and, yeah, made my heart sink a bit. I'm surprised I didn't blow the thing up when I turned it on. Things touching things where they probably shouldn't be. Even more what I see is a lot of reddish buildup around all the solder points on the tube connections. As well, the soldering all over seems to be a bit heavy.
I think this is going to be a bigger undertaking than I thought. No worries, I enjoy a good challenge. Replacing the caps might be short term to see if things are working. But I think that alone isn't going to be enough long term. Wiring and other things will need to be replaced as well. Why not just do it all at once?
Phil Nelson's beginner site was very informative. His knowledge of capacitor types for old radios was very insightful. You can see from the pics that there are a lot of old ones that are not very reliable and should just be replaced. I am looking into some more modern ones here: https://www.justradios.com
At this point I'm thinking of starting by replacing the capacitors and see if that gets the radio working properly. No point in re-wiring it without knowing what the root causes are? Would that make sense?
Some questions on the capacitors I am seeing:
The electrolytic one is rated mfd 20/20 on the schematic, but I don't see the voltage. The blue one in there now is VDC150. Without the schematic stating otherwise do I assume that is the correct voltage? I know that I can go higher in voltage, but I'm having a hard time finding one rated 20/20 at 150vdc.
Can the one in the middle that has the coil around it be replaced with a modern cap that doesn't have the coil?
Given all that, I'm looking for some thoughts/comments on what I've observed and what I might have missed.
Thanks again for any help!
John
