09-14-2014, 10:52 AM
This is the second 20 I am restoring, the first wa done 3 years ago and was the very first American tube radio I restored, a lowboy.
Now, after a perfunctory 10-minute checkup, and the premise that all caps have to go,
1. All resistors have to go, 50 to 100% up in values. But in 20 there are just 5 of them, common values and 1/2W is all that is required.
2. The wirewound reistor is fully good.
3. Both the choke and interstage audio xfmr are good.
4. I have done the speaker early this summer.
5. Some ground rivets are high in resistance, 10-12 Ohms which will need to be addressed.
I intend to try running a thick black-colored wire between those, this should be low inductance and will povide for a good groundung. Hopefully it won't create a loop as I will try to run the wire the shortest path fom Power supply (point 3 of the big resistor) two-prong, one to audio out, and one to RF.
Will see how it affects hum, should it exist of course.
That to me looks easier than re-riveting.
And lastly, the question I want to ask: yes I know the filter caps are typicaly repaced.
I also know Terry tends to keep those if they perform well.
Consideing those are huge fully potted paper caps (I remember they are ginormous) - what's the experts majority's opinion? Should I give them a test r should I ditch them no matter what?
Now, after a perfunctory 10-minute checkup, and the premise that all caps have to go,
1. All resistors have to go, 50 to 100% up in values. But in 20 there are just 5 of them, common values and 1/2W is all that is required.
2. The wirewound reistor is fully good.
3. Both the choke and interstage audio xfmr are good.
4. I have done the speaker early this summer.
5. Some ground rivets are high in resistance, 10-12 Ohms which will need to be addressed.
I intend to try running a thick black-colored wire between those, this should be low inductance and will povide for a good groundung. Hopefully it won't create a loop as I will try to run the wire the shortest path fom Power supply (point 3 of the big resistor) two-prong, one to audio out, and one to RF.
Will see how it affects hum, should it exist of course.
That to me looks easier than re-riveting.
And lastly, the question I want to ask: yes I know the filter caps are typicaly repaced.
I also know Terry tends to keep those if they perform well.
Consideing those are huge fully potted paper caps (I remember they are ginormous) - what's the experts majority's opinion? Should I give them a test r should I ditch them no matter what?
