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Gents
Over the week end I picked up one of those sky scrapper art deco classics-a 41-290- at an estate sale. I pulled the chassis out when I got home and cleaned it up and made sure the wiring was ok etc. It needed a glass dial and I replaced it with a scale from an old 41-280 set I had left over. I turned on the set, and to make a long story short I have two questions
If you are looking at the dial scale on the right hand side where the "Broadcast", "Standard" and "Short Wave" bands are noted, there is a lone pilot lamp in a housing that appears to be on a pulley system floating tied in to the actual pointer pulley sytem. This is different than the 280 where there are 3 seperate housings for the lamps. In any event, how do I wire the floating housing so it works correctly when changing the bands?
Second, the radio does in fact play and I can pick up a lot of stations. There is a louder than normal hum coming through. Do I have a condenser/filter problem or just a bad tube? I am waiting for my test equipment to arrive this week end (tube tester, signal generator and volt meter). Where should I start?
Thanks for alll your help in advance.
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Hi
DON'T TURN IT ON AGAIN until you replace your set's electrolytic capacitors! This, most likely, is the cause of the hum you are hearing - the electrolytic capacitors in your radio are failing. If one of them shorts out, it could take your radio's power transformer with it.
All of the paper capacitors and any out of tolerance resistors should also be changed; and you should either replace the insulation of the rubber-covered wires, or replace the wires themselves for safety and longevity. The reason I mention this is that the original wires in your radio are covered with rubber insulation which dries out, cracks, and falls off over time, which creates a safety hazard (shock/shorted wires/fire hazard/etc.).
I'll have to see if I can find my little drawing I made of how you need to restring the dial cord to operate that lamp pulley, scan and post it here.
--
Ron Ramirez
Ferdinand IN
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Mr. Philco, thanks for your reply. Ok, I won't turn it on again-at least until I have done what I need to do to replace the electrolytic capacitors. I will also go ahead and replace the paper caps and out of tolerance resistors. I am just starting the electronic aspect of this hobby so I am going slow. It also means that I don't fully know what in the heck I am doing, but I guess I have to start somewhere.
Thanks again for your help.
MG
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Finally found my (rough) sketch of the band indicator stringing for Models 41-250, 41-255, 41-256, 41-280, 41-285, 41-287, 41-290:
[Image:
http://i326.photobucket.com/albums/k420/...andind.jpg]
Hope this helps,
--
Ron Ramirez
Ferdinand IN
Posts: 34
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OK, thanks for the sketch. I think I understand it. I will have to take a pretty close look. I notice the coil spring. I assume this is the same type of coil spring that is on the scale pointer pulley sytem with the same purpose. I will see if my old 41-280 set still has one. I will let you know how this turns out.
Thanks again, MG
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City: Minneapolis/St. Paul MN
Madghost,
Is your 41-280 out of comission? I'm looking for a dial pointer for one of these. Is yours available?
Thanks in advance,
Bill
Sent from my Pentium II on the AT&T Dial Network
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The pointer I have for the old 280 is a jerry rig, but it should work. I am not used to the mechanics of these forums, but if you can give me your e-mail or address off line I will be happy to send it you.
SF/MG
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Drop me an email and I'll give you the vitals. Thanks!
Bill
Sent from my Pentium II on the AT&T Dial Network
Posts: 34
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Joined: Oct 2005
City: Collegeville,PA
OK, I am ready to start on the electronic restoration of my 41-290. I pulled down the "Replacing Capaciators in Old Radios" article off the Philco web site. Here is what I came up with taking readings off the caps themselves:
Non Electrolytic paper caps:11
2X .o5 mfd/200 Volts
1x ? mfd/400 Volts (part # 30-4518s)
4x .01 mfd/400 V (part # 30-4572)
2x.003 mfd/?V (part 4469)
1x .002 mfd/?V
1x ? mfd/? V (part 4472)
Two Electrolytic Caps
1x 12 mfd/400v (axal lead)
1x ? mfd/400 v (dual lead on one end)
The schematic I pulled down off the web at Nostalgia Air is in a very small font and I have trouble reading it. Also, it doesn't have the same complete parts list like I have seen on the some of the Zenith Schematics that inlude mfd and Volt rating in the parts table.
So, can I use the standard orange drop capacitors to replace the paper non elctrolytic using .05 .01, .033 and .022 replacements? Can somebody help me with the unknown Voltages and Mfd rates shown above?
As to the electrolytics, have I identified them all? Of the two I have id'd, can I use a 22mfd/450 or 630Volt replacement for the 12 mfdx400 V? What about the second one? Both of these were found underneath the chasis held in place with a soft metal clip to the chasis. Also, I can't seem to find a dual lead Electrolytic cap in my RD catalogue. Any tips?
Any assistance would be greatly appreciated.
Thanks much, MG
