01-29-2014, 02:02 PM
Last summer I stumbled across a $10 Philco console radio tucked away under a couple of worn out wooden lamps at a garage sale. While I do have substantial training with contemporary electronics, I have no experience at all with anything that predates the transistor, but at that price I had to give it a shot.
So far I have made two real mistakes: 1) I didn't remember to take a pre-teardown picture of the chassis until I had already un-mounted or de-soldered most of the wires from the Bakelite capacitor housing; 2) In the pictures I did take, it is not clear where the two black wires from the transformer are attached.
Regarding the black wires, I am fairly sure one of them solders onto the Bakelite housing at the terminal which has the grounding screw in it, but in the schematic I downloaded the other one (other end of the smallest coil in the transformer) ends with a symbol I do not recognize from school (the same symbol can be found on one end of the pilot lamp leads).
If anyone out there has a pic/drawing of how the Bakelite housing should have been connected up before dis-assembly, that would help me a lot at the moment.
Apart from that, I'm basically going through and replacing one rubber wire at a time: most of the ones near the transformers are badly shot but on the other side many of them still look to be on the dry side of usable. I've already gone into the power transformer and slid heat shrink tubing as far up the wires as it will go, however without a proper heat gun (I'm working on a computer desk in my apartment) I had to secure them with electrical tape rather than by shrinking. This has resulted in some longer lead wires than the originals... how critical is wire length for resonance in a system like this? I have also replaced the power chord it came with, which was itself a 1951 zip chord complete with a paper tag from the repair shop in Tracy MN that must have installed it (along with, I think, a newer Bakelite cap housing: this one has the yellow paint rather than the "hot stamp" on it).
Given what I have to work with and my lack of pre-transistor experience, my goal is to simply get the unit working while bolted into the original cabinet. If I have to replace a cap with something modern looking to make it work, than I will do so. On the other hand, there are indications that this unit has been overhauled before, so once I get the rubber wiring straightened out I may simply plug it in and see what I've got before trying to re-cap it.
BTW, is there any such thing as a cheap, reliable, short-range AM transmitter (something like the FM devices people use with iPods to make them work in cars that have very simple radios?). I've got several old computers here that I would like to try using to feed period-appropriate music into this radio without compromising the original electronics more than I have to.
So far I have made two real mistakes: 1) I didn't remember to take a pre-teardown picture of the chassis until I had already un-mounted or de-soldered most of the wires from the Bakelite capacitor housing; 2) In the pictures I did take, it is not clear where the two black wires from the transformer are attached.
Regarding the black wires, I am fairly sure one of them solders onto the Bakelite housing at the terminal which has the grounding screw in it, but in the schematic I downloaded the other one (other end of the smallest coil in the transformer) ends with a symbol I do not recognize from school (the same symbol can be found on one end of the pilot lamp leads).
If anyone out there has a pic/drawing of how the Bakelite housing should have been connected up before dis-assembly, that would help me a lot at the moment.
Apart from that, I'm basically going through and replacing one rubber wire at a time: most of the ones near the transformers are badly shot but on the other side many of them still look to be on the dry side of usable. I've already gone into the power transformer and slid heat shrink tubing as far up the wires as it will go, however without a proper heat gun (I'm working on a computer desk in my apartment) I had to secure them with electrical tape rather than by shrinking. This has resulted in some longer lead wires than the originals... how critical is wire length for resonance in a system like this? I have also replaced the power chord it came with, which was itself a 1951 zip chord complete with a paper tag from the repair shop in Tracy MN that must have installed it (along with, I think, a newer Bakelite cap housing: this one has the yellow paint rather than the "hot stamp" on it).
Given what I have to work with and my lack of pre-transistor experience, my goal is to simply get the unit working while bolted into the original cabinet. If I have to replace a cap with something modern looking to make it work, than I will do so. On the other hand, there are indications that this unit has been overhauled before, so once I get the rubber wiring straightened out I may simply plug it in and see what I've got before trying to re-cap it.
BTW, is there any such thing as a cheap, reliable, short-range AM transmitter (something like the FM devices people use with iPods to make them work in cars that have very simple radios?). I've got several old computers here that I would like to try using to feed period-appropriate music into this radio without compromising the original electronics more than I have to.
