Hi guys,
I would like to restore an antique RCA shortwave receiver to working condition. I have examined it and tried to power it up resulting in the power transformer draining wax from it, accompanied by a burning odor.
So, the capacitors are all shot...most are the oil-paper type with 2 very old electrolytics that will definately not work.
The resistors might be shot...I will go through and read values and get replacements.
Do tubes go bad? The radio worked just a few years ago, I assume the tubes would stay good?
Should I replace all the components with the point-to-point method used in the original consruction or find a schematic and build a PCB to replace the point-to-point mess? I assume I have a bettter chance of getting it running again if I just replace each part one at a time, swap an old part for a new one, one at a time until all new parts and wires are in there.
Does anyone have any experience in this? It is a large, stand-alone cabinet. There are only a couple tubes and one small power transformer that says:
117 V
75W
B 95-756
There are 9 wires going into it, with 2 of them the 120VAC input for power. I can get all the other parts by reading their codes, but this transformer is completly foreign to me.
Are there any websites with info on this kind of thing?
Any help would be greatly appreciated!
-Matt
I would like to restore an antique RCA shortwave receiver to working condition. I have examined it and tried to power it up resulting in the power transformer draining wax from it, accompanied by a burning odor.
So, the capacitors are all shot...most are the oil-paper type with 2 very old electrolytics that will definately not work.
The resistors might be shot...I will go through and read values and get replacements.
Do tubes go bad? The radio worked just a few years ago, I assume the tubes would stay good?
Should I replace all the components with the point-to-point method used in the original consruction or find a schematic and build a PCB to replace the point-to-point mess? I assume I have a bettter chance of getting it running again if I just replace each part one at a time, swap an old part for a new one, one at a time until all new parts and wires are in there.
Does anyone have any experience in this? It is a large, stand-alone cabinet. There are only a couple tubes and one small power transformer that says:
117 V
75W
B 95-756
There are 9 wires going into it, with 2 of them the 120VAC input for power. I can get all the other parts by reading their codes, but this transformer is completly foreign to me.
Are there any websites with info on this kind of thing?
Any help would be greatly appreciated!
-Matt
Hi,
When I restore an old radio, I replace ALL papers and electrolytics capacitors, it's more safe. If you have a metal can on a chassis, only cut wires and put new caps under chassis (new ones are smaller, so easy to place). Do not remove can! You will preserve originality of radio with this method. Do not replace the mica caps with colors dots on it (theses caps are square or rectangle and brown, they are always good. Habitually resistors are OK and anyway, tolerance of resistors and caps is about +-20%!! You can put anything and the radio will still work... I always put a fuse between 120V ac wire and on/off switch (less than 1A, you can calculate with AC voltage and power consumption on plate in back of radio), it's safe to put one, because theses radios are really old and we never know when a trans or a rectifier tube will fail. Check also if primary and secondary of all trans are open or not with a ohm meter.
If you have any questions, just ask.
Jean-Francois
When I restore an old radio, I replace ALL papers and electrolytics capacitors, it's more safe. If you have a metal can on a chassis, only cut wires and put new caps under chassis (new ones are smaller, so easy to place). Do not remove can! You will preserve originality of radio with this method. Do not replace the mica caps with colors dots on it (theses caps are square or rectangle and brown, they are always good. Habitually resistors are OK and anyway, tolerance of resistors and caps is about +-20%!! You can put anything and the radio will still work... I always put a fuse between 120V ac wire and on/off switch (less than 1A, you can calculate with AC voltage and power consumption on plate in back of radio), it's safe to put one, because theses radios are really old and we never know when a trans or a rectifier tube will fail. Check also if primary and secondary of all trans are open or not with a ohm meter.
If you have any questions, just ask.
Jean-Francois
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