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Now that I have my 41-220 working I am going to start a rebuild on a 66B tombstone and was curious if there were any pitfalls to watch out for? A good start is that the IFs and coils check good. Bad thing is the choke shows open. Also, the speaker cone is pretty well tore up so will need a new cone for it.
(This post was last modified: 01-20-2013, 10:58 PM by
Jim Dutridge.)
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Jim,
Just finished two 66s- one of which is a B. Both had good coils and good speakers. Simply had to re cap and replace resistors. They both had frozen bandswitch switches. Simply heat the shaft with soldering iron and use something like WD-40 and eventually they will free up. One of the switches had actually broken so I had to remove a fix. Other than having to correct someones previous attempts at repair, they both came out great. The guys on this site are super! Nothing they can't help with.
Good luck,
Joe
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Thanks Joe. I just ordered the parts I'm out of for this radio last night. I'll probably start with the raised board section. There are a few resistors on the board that are way OOT and was thinking about just cutting their leads and tacking them in place on top of the board and mounting the replacements underneath. I'll still need to find a replacement choke unless I get lucky and there is only a break under the outer wrapping.
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Following some google threads on the choke I was able to pull it apart and find the break. Resistance now reads about 2060 ohms so if all goes well with putting back together
I think I'll have a winner.
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1 question I forgot. Now that I have found the break what do I use as far as an insulating paper? I still have the very outer section but do I use for the inner section? Seems like it was some kind of mixture between wax and a fiber(?) tape.
(This post was last modified: 01-23-2013, 06:14 PM by
Jim Dutridge.)
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HMMM, looking at the resistors on the raised board the are some decrepencies. Example is #43 which the schematic says is a .1MEG and the parts list also says its a .1MEG but the color code stated is WHITE-WHITE-ORANGE which is a 90K and thats what is physically on the board. Guess Philco wasn't very good at quality control when it came to publishing their schematics.
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WHITE-WHITE-ORANGE would be 99K, that's pretty close to .1 meg. I have seen this in several Philcos.
Steve
M R Radios C M Tubes
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Yep, Philco often used 99K resistors where the schematic called for 100K. The 1000 ohm discrepancy didn't matter, it was well within the 20% (or more) tolerance of those old resistors.
--
Ron Ramirez
Ferdinand IN
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Same on mine with the resistors. I replaced resistors with what the schematic called for. worked great.
Joe