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Hi all! Here is the Philco 50 that I just started.
[Image: http://i1072.photobucket.com/albums/w374...0pekgl.jpg]
I bought it off of eBay - and it arrived intact (barely). There's a bunch to reglue before I'd trust the cabinet to hold a radio again - but since this is the electronics restoration let's dive in!
The chassis seems not too bad at first glance (not much rust) but it has definitely been a mouse house!
[Image: http://i1072.photobucket.com/albums/w374...qxyxe2.jpg]
[Image: http://i1072.photobucket.com/albums/w374...zwr78q.jpg]
In fact, the mouse skeleton was still at the bottom of the tuning capacitor! Apparently, after sleeping upstairs in the tuning capacitor the mouse like to go down to the kitchen and munch on wires. Note the long, now bare wires underneath. 
[Image: http://i1072.photobucket.com/albums/w374...hsvjlq.jpg]
[Image: http://i1072.photobucket.com/albums/w374...mj8wex.jpg]
The speaker looks like a really cute miniature version of the 20/70/90 speaker - and is in nice shape - tests good. The mouse never found the speaker cable so it's in pristine shape.
[Image: http://i1072.photobucket.com/albums/w374...webh3y.jpg]
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The first thing I did was tackle the chewed wires - no way I'm ever powering it up like that!
[Image: http://i1072.photobucket.com/albums/w374...asc2xo.jpg]
Ah - much better. I also took off the bypass filter block so that I could give it an overnight soak it in Evaporust before restuffing.
[Image: http://i1072.photobucket.com/albums/w374...enbi5a.jpg]
These caps aren't labeled on the schematic - and the service bulletin only gives the values. Fortunately Ron's excellent annotated schematic for the Philco 50 is still floating around in the Ether. 
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If it turns out your on-off switch is faulty, I have another one that I picked up while working on my 50. Originally I thought mine was dead but a liberal deoxit dose cured it.
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Thanks Bob! That kind of you to offer. Fortunately my switch seems to be working.
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Here are the new bypass bank caps:
[Image: http://i1072.photobucket.com/albums/w374...tirsao.jpg]
All wrapped up and ready to go back into a nice rust-free can. Thank you Evaporust!
[Image: http://i1072.photobucket.com/albums/w374...uxovcb.jpg]
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I had a 50 a few years ago and one of the picky things that bugged me about it was that the spkr seem to cause the front panel bow out where it attaches at the bottom. I was going to add a thin piece of plywood shaped like the cardboard that hold the grille cloth but sold it before I got roundtoit.
Looking good on the underside, I see it has a few 99K resistors. On my 660 the 99K where listed has 100K on the parts list. I kept looking for brn-blk-ylw resistors not the wht-wht- org. Caught me off guard.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
(This post was last modified: 12-20-2016, 12:03 AM by Radioroslyn.)
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Ha ha - yeah I know what you mean Terry. The 50 parts list (at least the service bulletin) does actually list 99K - but that seems to be the exception.
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(12-20-2016, 12:02 AM)Nathan Slingerland Wrote: Here are the new bypass bank caps:
[Image: http://i1072.photobucket.com/albums/w374...tirsao.jpg]
All wrapped up and ready to go back into a nice rust-free can. Thank you Evaporust!
[Image: http://i1072.photobucket.com/albums/w374...uxovcb.jpg]
My your busy little bee aren't you!!!
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
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Joined: Dec 2009
City: Roslyn Pa
(12-20-2016, 12:05 AM)Nathan Slingerland Wrote: Ha ha - yeah I know what you mean Terry. The 50 parts list (at least the service bulletin) does actually list 99K - but that seems to be the exception.
I should read those SB more often it would save me a lot of grief.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
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City: Seattle
State, Province, Country: WA
Speaking of resistors, last night I went through and checked them against measured values:
No. Expected Actual Verdict
9 32K 103K bad!
11 10K 11.2K good
13 240K 346K bad
14 490K 593K a bit off
20 490K (infinity) really bad!
21 160K 214K bad
23 15K 16.1K good
26 25K 23.5K good
29 99K 140K bad
27 99K 148K bad
So most are pretty far out of tolerance.
Time to break out the repro resistor production line!
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To make reproduction dogbone resistors I start with polystyrene tubing made for model railroads:
http://www.evergreenscalemodels.com/Shap...d%20Tubing
The best thing about it is that it comes in a number of different diameters - for whatever wattage resistor you need to reproduce. It's readily available on eBay and Amazon.
I use a hobby mitre saw to cut it to length. All of the out-of-tolerance resistors on this Philco 50 are 1/2W and 1" long.
[Image: http://i1072.photobucket.com/albums/w374...mnwdux.jpg]
I use wire snips to make a small notch for a length of bus wire on each end. I used 5.5" lengths of 18ga bus wire for these.
I use a wire wrap tool to roll up the original resistor leads and solder the bus wire to each end:
[Image: http://i1072.photobucket.com/albums/w374...eiiykw.jpg]
Then I insert the resistor plus bus wire leads into the tube and wrap the leads around the outside:
[Image: http://i1072.photobucket.com/albums/w374...brytpa.jpg]
And finally solder the wrapped leads so that they'll stay together. Finally, I use hot glue to fill / seal up the ends.
[Image: http://i1072.photobucket.com/albums/w374...xpshbm.jpg]
I know I've seen others use JB-Weld to hold things together and to fill the ends - which works great, but is a bit messy and of course takes time to cure. The above method lets me build the resistors in one pass, which is helpful since painting takes a day or so.
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Now to paint those resistors!
It usually takes two coats of paint for the body color with an hour or two between coats. I use a small brush to apply the body paint.
[Image: http://i1072.photobucket.com/albums/w374...gbcn54.jpg]
I let the body dry dry over night. Then I apply the end and dot colors using a q-tip.
[Image: http://i1072.photobucket.com/albums/w374...5jzqxz.jpg]
All set!
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Sweet!  Nice repro job on those resistors!
If I could find the place called "Somewhere", I could find "Anything" 
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
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Nathan
Great job on those.
To be frank I still am not sure how plastic will stand to heat should the dissipation be on the order of 1/4W or so, considering it also insulates the resistor from being cooled by air.
For those in 100K and up range the dissipation is small.
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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