05-20-2024, 11:07 PM
1 - The battery harness terminal strip easily removable and has the battery harness connected (soldered) to it. It mates to specific terminals on the long terminals strip. It may still be present but it may be the terminal strip used with the 104 power unit.
Is there a large cap bank in the lower battery box? If so there should be one large block is a 4mf that is across the 24 volt filaments.
2 - It is in the upper right corner of the radios frame, if not, it is missing...
3 - There is no way to "shunt" anything inside the catacomb to effect a repair. However, it is possible to bring the plate circuit of the first audio out to feed an input transformer on a power amp like a 210. That mod is not internal to the cat as all 8 tube cats are identical, even in the Radiola 30 and any of the Brunswick/Electrola models. If you find a cat with 7 tubes, there is a block off plate covering socket eight, that cat is for a power amp but all internal circuits are present.
4 - No seals means the cat was repaired outside of RCA, returning the original rosin would create a failure soon as it shrinks considerably more. It is possible the shop had "fresh" potting rosin on hand.
5 - Yes, The strip should be removed to melt out the cat. I fear that the Receptrad power unit requires those resistors to set up bias and it means that all the filaments are wired in series. That is not good as an ARBE cannot provide 24 volts at 60ma...
Take a look and see if the voltmeter jacks have been disconneted or at least one of them...
You will have to find a jumper strip so filaments are in parallel. I will have search and see if I have one. Failing that a WTB in the classifieds for a 8 tube cat with the jumper strip.
Do the go/no-go test as described in the RCA notes. Note the defects and write down. If your lucky there will be no problems. The information is vital to locating bad circuits once the cat is melted out.
Manipulating an open cat is risky as the wires are very fragile.
The ARF classifieds may be a better source for old catacombs. Some 10 years ago I found several.
Be SURE you have the correct loop, a 28 loop is center tapped, check the continuity of the loop. If there is no center tap it is for a Radiola 25 and the wrong inductance, even if a tap is created.
Best to take before pix. As there are no early pix that are clear enough to deal with correcting altered wiring.
BTW there is at least on collector that saves cat rosin, used to re-stuff tubular capacitor ends...
Chas
Is there a large cap bank in the lower battery box? If so there should be one large block is a 4mf that is across the 24 volt filaments.
2 - It is in the upper right corner of the radios frame, if not, it is missing...
3 - There is no way to "shunt" anything inside the catacomb to effect a repair. However, it is possible to bring the plate circuit of the first audio out to feed an input transformer on a power amp like a 210. That mod is not internal to the cat as all 8 tube cats are identical, even in the Radiola 30 and any of the Brunswick/Electrola models. If you find a cat with 7 tubes, there is a block off plate covering socket eight, that cat is for a power amp but all internal circuits are present.
4 - No seals means the cat was repaired outside of RCA, returning the original rosin would create a failure soon as it shrinks considerably more. It is possible the shop had "fresh" potting rosin on hand.
5 - Yes, The strip should be removed to melt out the cat. I fear that the Receptrad power unit requires those resistors to set up bias and it means that all the filaments are wired in series. That is not good as an ARBE cannot provide 24 volts at 60ma...
Take a look and see if the voltmeter jacks have been disconneted or at least one of them...
You will have to find a jumper strip so filaments are in parallel. I will have search and see if I have one. Failing that a WTB in the classifieds for a 8 tube cat with the jumper strip.
Do the go/no-go test as described in the RCA notes. Note the defects and write down. If your lucky there will be no problems. The information is vital to locating bad circuits once the cat is melted out.
Manipulating an open cat is risky as the wires are very fragile.
The ARF classifieds may be a better source for old catacombs. Some 10 years ago I found several.
Be SURE you have the correct loop, a 28 loop is center tapped, check the continuity of the loop. If there is no center tap it is for a Radiola 25 and the wrong inductance, even if a tap is created.
Best to take before pix. As there are no early pix that are clear enough to deal with correcting altered wiring.
BTW there is at least on collector that saves cat rosin, used to re-stuff tubular capacitor ends...
Chas
