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I just finished replacing caps,installing the rebuilt cartrige in my RP-3. Just to find out it has to sit no more then 2 feet from a radio to work. I tested the tubes (they're good), checked resistor resistance(w/in specs), played with the tuning adjustment and doubled checked connections and antenna. From what I read the range should be up to 25 feet or was this a marketing ploy. Any ideas! Thanks, Richard
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There are quite a few factors in making a wireless record player work. Philco coupled the output of the oscillator to the AC line through a small mica capacitor. Other companies had a third wire in the line cord for an antenna. This was about the same thing as Philco had done, as they used the cpcacitve coupling into the line with the third wire.
The radio receiver antenna, be it loop or regular wire antenna can make a difference. If the set has a filter network in its AC line input, that will block reception from the wireless phono.
I assume that your RP-3 has the same oscillator in it as had the RP-1 and -2 models. I have a 41-RP-2 that friends gave me. They bought it new, and we kids spent scores of hours listening to records on it, playing it through an old US R&T "Radiotrope" console about 25 feet away in the living room. It worked like gangbusters. You could also pick up the player elsewhere in the house. It was broadcasting through carrier current transmission.
You might also check the crystal pickup output. They used a high output cartridge in the pickuip on those sets, to get sufficient modulation.
The power supply in those oscillators ran the 6A7 at about 150 Volts, so it wasn't wringing a lot of RF out of it. You might check the power supply output, though it's probably O.K.. A check of the 6A7 might show a weak tube. TYhe 84 rectifier certainly wasn't being pushed to capacity!
Those players are so disgustingly simple that it's hard to find something that could be wrong.
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Thanks for the response. I know it is the RP-3 that has the problem. I tried it with several other pre-war radios with the same response. I will recheck the tubes and the voltage. Maybe a new cap went south. How would I check the cartridge for output? I just had it rebuilt by West Tech. Great looking record player. Real conversation piece. Now to get it working right. Thanks, Richard
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You'd test a pickup cartridge for output using a vacuum tube voltmeter on the AC scale. You'll need to get about 2 volts peak out of it before it can drive the 6A7 to full modulation. It's hard to say what the piezo element was that the guy put in your cartridge. M any of the ceramic pickup cartridges don't have much voltage output, and that may be what they guy used to put in your cartridge.
You may have a problem now, because if it's a low output crystal and you never specified high output, you could be stuck with what you have.
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Thanks Doug, Checked voltage at pickup.(OK) In doing so decided to make sure the connections were good. Tightened all related points. Put it all together, retried. Now I can pick it up in the next room. Funny how a bad connection can ruin a whole day. Thanks again, Richard
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I haven't gotten my 42RP-2 to work yet either.
Dan('
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