Ron's RCA T7-5 Electronic Rescue
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Arran
That's exactly how I am working with these forked terminals and I still managed to break one of the three fingers on one terminal (the only one so far - knocking wood). Only, I'm using desoldering braid; it takes longer but removes more solder. Plus, my old desoldering bulb is worn out and not as efficient as it was a few decades ago. I keep forgetting to find and buy another. Maybe I'll see if Mouser has any, since I now need some large resistors and terminal strips to replace the Candohms in this radio.
Speaking of J-hooks, I discovered something when replacing a resistor and capacitor at the 2nd IF transformer. Do you know the technique used by RCA to attach wires and components to the heavy wires coming out of the IF transformer itself? J-hooks! Yes, every IF transformer lead terminates in a J-hook. Imagine, the great RCA doing something like that.
If I don't forget, I'll take a close-up photo showing that later.
> and they used the same forked terminals on the tube sockets as Ron's T7-5 uses, the American RCAs from that era did not according to what Ed Holland found in his RCA 110K2
My T7-5 is American and uses those terminals on the tube sockets. Maybe RCA got away from those by the time the 110K2 was made.
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Ron Ramirez
Ferdinand IN
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Today's progress:
Having decided to replace both Candohms, the first order of business was to replace the one mounted on the piece of metal running front to back under the chassis. This was R16-R17-R18.
[Image: http://www.philcoradio.com/images/phorum...-5_013.jpg]
Then, after removal of the old Candohm, I installed two terminal strips in place:
[Image: http://www.philcoradio.com/images/phorum...-5_015.jpg]
After this, the piece of metal was reinstalled in the chassis to see how things looked:
[Image: http://www.philcoradio.com/images/phorum...-5_016.jpg]
Then I removed the metal piece again.
[Image: http://www.philcoradio.com/images/phorum...-5_014.jpg]
I removed it again so I could access the terminals of the 6K7 and 6A8 tubes. I then proceeded to replace several more rubber-covered wires and a few components.
The chassis now looks like this:
[Image: http://www.philcoradio.com/images/phorum...-5_017.jpg]
There are only a few more rubber-covered wires to replace. This radio uses cloth wires for the filament string and cloth in a few other places; these appear to be all good. Oh, and I also removed electrolytic C22, since having it out of the way helped me reach a few critical areas. C22 will be restuffed with a new Solen 10 uF cap and then reinstalled later on.
I feel that I have made good progress today on this radio and hopefully, things will go more smoothly from here.
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Ron Ramirez
Ferdinand IN
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I have just ordered replacements for all of the Candohm sections.
While I was at it, I also ordered replacement resistors for the Candohm in my RCA C15-3, since I expect to restore it later this year.
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Ron Ramirez
Ferdinand IN
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The terminal strips look nice and neat on that metal piece. I've been looking for some good terminal strips like that. Where do you get yours?
You made some very good progress today!
Greg V.
West Bend, WI
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Thanks Greg,
I bought these from Mouser Electronics. I was going to order some longer ones for this job but instead, I decided to make do with what I already had on hand.
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Ron Ramirez
Ferdinand IN
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Thanks, Ron. I'll have a look there.
Greg V.
West Bend, WI
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Nice work Ron!
And thanks for the reminder about detachable chassis sides. This helped me get to the last three resistors on the 110K2.
I've not had to work on a radio using the Candohm resistors
Ed
I don't hold with furniture that talks.
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Oddly, I've never had a candohm fail! I suppose it's only a matter of time, though...
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I just had enough time to replace one resistor and two mica caps tonight. Bot looking at it, there isn't a lot more to be done. Two more paper caps, the three electrolytics, one or two more resistors, and of course replacing the Candohm sections with new resistors which are supposed to be here tomorrow.
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Ron Ramirez
Ferdinand IN
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Thanks Ken.
Parts arrived from Mouser today. I have now replaced the three section Candohm with individual resistors. I also replaced a few more wires, another mica cap, and another small resistor.
Photos later.
Oh, and I now have my first new desoldering bulb in decades. And you know what? I still prefer the desoldering braid...
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Ron Ramirez
Ferdinand IN
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Ron;
I found that my desoldering bulb worked better after I drilled out the tip, the reason I drilled it out was so that I could clear blockages with a finishing nail. However the rubber bulb on it went bad so I'm gone to using one of those spring loaded solder suckers, it also works but the tip is worn out, but it's much easier to clean out though.
Regards
Arran
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Photos from last night, as promised:
First, here is how the chassis now looks after the work I did last night.
[Image: http://www.philcoradio.com/images/phorum...-5_018.jpg]
A close-up of the new replacement for the three section Candohm:
[Image: http://www.philcoradio.com/images/phorum...-5_019.jpg]
And Arran, I had promised this photo for you back in post #16, top of this page - here is a close-up of the underside of the 2nd IF transformer, showing the J-hook connections:
[Image: http://www.philcoradio.com/images/phorum...-5_020.jpg]
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Ron Ramirez
Ferdinand IN
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Hi Ron,
Nice work. If you don't mind my asking, What is the wire you are using e.g. gauge, strands etc.? I do see that it is 600V
Thanks
Ed
I don't hold with furniture that talks.
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Ed
It is the plastic-coated hookup wire from Radio Daze. 22AWG.
http://www.radiodaze.com/22awg-solid/
http://www.radiodaze.com/22awg-stranded/
As I mentioned previously, I had this wire left over from when I rebuilt a Philco 41-616.
The white is solid. When I started on this project I could not find my other spools of solid wire so I used stranded for the other colors...until I stumbled across my stock of solid hookup wire a few evenings ago ![Icon_crazy Icon_crazy](https://philcoradio.com/phorum/images/smilies/icon_crazy.gif) So I'll finish up with solid, since that is what RCA originally used.
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Ron Ramirez
Ferdinand IN
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