04-16-2018, 03:56 AM
Ed;
This is often the case, once you start poking around under a radio you begin to find stuff that just has to be dealt with. While checking over a new radio I acquired, I started figuring out what I needed to replace, and how to replace it, since the filter caps were shot I thought about replacing those using a terminal strip. Whilst looking at terminal strips, and at possible wiring arrangements for it, I ran across an older unfinished project and decided to work on that first, since it was already out on the bench. So yesterday I worked out a game plan, found a suitable terminal strip, and soldered it under the chassis right next to one of the twist tabs holding the old condenser can in. Then I started on routing the wiring, the wire from the 5Y4 filament to to the former input cap was too short to reach the new terminal, at least 1/2'' too short, then I noticed a 100 Ohm resistor that was supposed to be connected to the output filter cap was measuring up at 1520 ohms, over 50% off spec. Next I need to figure out where to put the bypass electrolytic, it's connected to the screen grids on three tubes, it used to be located in the old can too. Then I looked at the original power cord, it has bare wires showing right where it enters the molded plug, and I will need to replace the crappy wires going to the loop antenna, more work!
The set in question is a Canadian RCA Victor model A-30 from 1940, same era as your 100K2, except it has a single ended output, five bands, and an untuned RF amplifier stage. I don't know if your set used this style of socket but the terminals under the tube sockets are actually forked, no holes, when you want to attach a wire or a component lead, you spread the middle section of the fork apart from the two outside sections with a thin screwdriver, stuff the lead or wire in-between, pinch the sections slightly closed, then solder, you don't have to wrap the wire around the terminal like one with holes. Having a solder sucker is really useful for cleaning these or any other terminal off, saves lots of time. I've never had an RCA or G.E set (both are similar in Canada) that was a dog in terms of performance, even the five tube ones, they seemed to design and build their tubed circuits and parts rather well.
Regards
Arran
This is often the case, once you start poking around under a radio you begin to find stuff that just has to be dealt with. While checking over a new radio I acquired, I started figuring out what I needed to replace, and how to replace it, since the filter caps were shot I thought about replacing those using a terminal strip. Whilst looking at terminal strips, and at possible wiring arrangements for it, I ran across an older unfinished project and decided to work on that first, since it was already out on the bench. So yesterday I worked out a game plan, found a suitable terminal strip, and soldered it under the chassis right next to one of the twist tabs holding the old condenser can in. Then I started on routing the wiring, the wire from the 5Y4 filament to to the former input cap was too short to reach the new terminal, at least 1/2'' too short, then I noticed a 100 Ohm resistor that was supposed to be connected to the output filter cap was measuring up at 1520 ohms, over 50% off spec. Next I need to figure out where to put the bypass electrolytic, it's connected to the screen grids on three tubes, it used to be located in the old can too. Then I looked at the original power cord, it has bare wires showing right where it enters the molded plug, and I will need to replace the crappy wires going to the loop antenna, more work!
The set in question is a Canadian RCA Victor model A-30 from 1940, same era as your 100K2, except it has a single ended output, five bands, and an untuned RF amplifier stage. I don't know if your set used this style of socket but the terminals under the tube sockets are actually forked, no holes, when you want to attach a wire or a component lead, you spread the middle section of the fork apart from the two outside sections with a thin screwdriver, stuff the lead or wire in-between, pinch the sections slightly closed, then solder, you don't have to wrap the wire around the terminal like one with holes. Having a solder sucker is really useful for cleaning these or any other terminal off, saves lots of time. I've never had an RCA or G.E set (both are similar in Canada) that was a dog in terms of performance, even the five tube ones, they seemed to design and build their tubed circuits and parts rather well.
Regards
Arran
