Greetings: Instead of replacing the 35W4 with open heater, replace it with a 1n4007 or similar diode and substitute a 12uf non-polarized capacitor to drop the heater voltage. To drop the cathode voltage to 122vdc, add a small series resistor. The #47 dial lamp draws 150ma itself with a 6.5v drop, parallel it with 100 or 110 ohms to pass the nominal 60 ma. radio current while establishing the voltage drop for the lamp. You can use the empty rectifier socket to mount the added components: pins 3+4 for the 12 uf dropper cap, pins 5+7(cathode end) diode, pins 4 & 6 for the lamp parallel resistor.
Hi James. I may need to do that someday; thanks for the info. In this case, I just grabbed another 35W4 - LOL. I did work with a solid state replacement of a cold cathode 0Z4 rectifier (no heater) where I used UF4007 diodes with some 3W resistors in case the diode(s) shorted. That was on the last part of the Chevy radio series. Thanks again for the suggestion.
This was an excellent two video troubleshooting series. A quick fix would not have been as interesting. You do a great job with these radio repairs PF.
That was an odd problem with the metal shield of the IF transformer. They used to use thin cardboard fish paper inside to insulate the interior of earlier and bigger IF transformers. That won't work here as the white plastic ends are very much tight to the shield but you can spray clear laquer inside and let it dry OR paint the close to the shield metal parts with clear fingernail polish if you run into the problem again. It is an old trick given in a magazine I saw from decades ago. Excellent work on this rather challenging radio there PF. Part of the learning in the repair of tube radios. Steve
Ended up working pretty good, but it did take a bit. Gotta love those radios with multiple problems. NOT! I'm looking forward to getting back to both the RCA's I worked on recently. Those 'other' things you spoke of have prevented me from doing just that. But I'm getting closer to it each day. :)
@@PracticallyFixed Back doing fine, knock on wood, it's our BDEK business that is causing all my problems now, just not enough room in the workshop for all those radios and kits to be shipped out, etc. :)
Hello, I'm new to your channel and started with part 1 of this 2-part series and learned a lot and enjoyed watching even more. Great job of hanging in there on that 1st IF Transformer! I was pleasantly surprised to hear the Astros on the radio too. I'm in Spring, but was born and raised in Houston. I graduated Austin Sr High in '74. I worked in IT for 10 yrs at Schlumberger and 25 years at Baker Hughes. I'd like to make the acquaintance of people into tube radios. Do you know of a group or club in the area? I had a Zenith Y832 I picked up at a Goodwill store back in '72. I loved that radio! I'm looking for another one now and am putting a small work bench setup together to maintain it and my tube hifi system... I'll continue to follow along. Cheers - Luther
Hi Luther, and thanks. I am also a native Houstonian from near the Astrodome. Yes there is a club in Houston, Houston Vintage Radio Association - HVRA dot org. On their webpage check out the newsletter The Grid Leak for upcoming meetings and events. Yearly dues are $20 and you can join on site of one of their events. Sometimes at their auctions (you have to be a member, but can join before they start) you can score some radios, etc in various state of repair and not too pricey to learn on. If you are setting up a bench, take a look at the referenced videos in my show notes on bench safety. When you get into equipment with power transformers, the voltages are much higher than on these all American 5 radios. Glad you enjoyed this series, there are several more to choose from here, just visit my youtube page and check out Playlists. Don't forget to Comment and Thumbs Up, it helps out! Good luck!
You are welcome. I noticed the 2nd Quarter Grid Leak isn't posted on the site yet, but check back often as it should be coming out soon. Don't forget to chip in in the comments sections of these videos - it helps Thanks
You bulldogged it all the way and got the results. Hat off to you sir! Have you seen those pcb retrofit IF rigs yet? Just saw a vid the other day and it was pretty slick. Fit right in the can