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I am in need of some help with a Philco 20, that I am working on. Here is a link to the schematic I am using:
http://www.nostalgiaair.org/Resources/582/M0029582.htm
I have an open filter chock, item 20. Can someone tell me what size of chock I need or what I can use as a substitute.
Posts: 26
Threads: 7
Joined: Dec 2011
City: Eagle,
State, Province, Country: ID
My mistake it is item 27 on the schematic
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Joe
I am not sure where all my papers are after the move, so I cannot look into them, but if no one knows off hand, take tube data sheets, add all tubes' max currents at their respective plate Voltages (I think you only need to account for on of the 71A as it is a pushpull) and you will have more or less the load current going through the choke.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
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Well, you have nothing to lose, so try to carefully disassemble the bad choke. Sometimes the lead -to- winding connection gets corroded and fails. Picture of chassis might help. Yes, you could substitute a resistor and increase the filter capacitor values moderately instead of using choke, you need to replace the filter capacitors anyway. When these set were made electrolytic capacitors were expensive, and copper wire was cheap. That's why.
Posts: 26
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City: Eagle,
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Oh, Thank you for your reply. I did get this Philco 20 up and running. Like someone mentioned earlier to try and fix the choke. Well, with nothing to lose I did take the choke apart and did fine a broken wire but it broke somewhere IN the choke. I managed to to find one winding, cleaned the wire and added a new lead. I assembled the choke and installed in the radio. Using a Variac, and meters I applied power. All seemed well, then the current increased, then varied and SMOKE. So, I went to option 2 - buy another choke. Well, I ordered the Triad C-7x and the radio is now working just fine.
FYI to anyone needing a replacement choke for a Philco part number 4231 the Triad C-7X is an GOOD replacement. The size is identical and electrically it is really close.
THANKS TO ALL FOR YOUR HELP AND INPUTS.
