New Philco project on the bench
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Last night I was a bit bored so I pulled out one of my garage sale finds, one that I bought from another collector who gave up on it. It's in a nice wooden cabinet with a curved top and it's a Philco model 84. No not the Philco model 84 that you are thinking of, this is a Canadian Philco Model 84, a five tube AC/DC set, black glass dial, and a mahogany cabinet, I think from 1948-49. The tube lineup is 35Z5, 50L6, 14C6, 12BA6, and a 7A8, seems to be related to the Transitone series, a very simple but handsome set. Anyhow I did get it to play but it did suffer from some sloppy workmanship, such as a filter condenser hog tied to the back of the speaker, likely why the previous owner had trouble getting it working. I don't know how hard it is to post pictures but I have a copy of the Philco service booklet for this set with photos, and those of the related models, that I could show. It should be a fairly quick project, most of the parts are new, they just have to be checked and re-installed, but it is getting new filter condensers that will fit under the chassis
Happy Christmas
Happy New Year
Arran
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I have a correction to make, the tube was a 14B6 not a 14C6. I am still working on the set, found out that the previous owner removed and replaced a few condensers with ones of completely the wrong values. He substituted a .0001mf in place of a 47 mmf (pf), and a 150 mmf in place of a .02 mf. As I said before the P.O mounted one of the filter condensers to the back of the speaker, to hook it up he ran two wires up through a hole in the chassis and left the leads of the condenser exposed in mid air. A wonderful way to make an AC/DC set even less safe, how do some people live so long?
Happy Christmas
Happy New Year.
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City: Grand Rapids, MI
Posts: 4,639
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Joined: Sep 2008
City: Sandwick, BC, CA
I've just about finished overhauling this set, it has been taking longer then I thought, but that's pretty normal when going back over someone else's work. The set seems to be from around 1949-50 according to the RCC manuals, but it looks like a Canada only wooden model using a similar chassis to the US Transitones, perhaps a model 520? I found a few bad resistors, the worst being a 69,000 ohm resistor supplying the screen grids of the converter and IF amplifier tubes, it was reading 530,000 ohms. I think that this may explain the low volume situation. I replaced the choke resistors in the power supply, one was a one watt 220 ohm resistor, the other a half watt 1200 ohm unit, replaced each with larger wattage resistors. I also replaced the plate resistor for the 14B6 while I was at it since it was next in line, it was reading 540,000 rather then 470,000 ohms, it won't make much difference in performance but it likely would have gone open at some point anyhow. So two more paper condensers to change, then the filter condensers, and we are onto alignment.
Happy New Year
Arran
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City: Sandwick, BC, CA
An update on the Philco, there was indeed a U.S equivalent to this model, the model number escapes me at the moment, so only the model number itself was Canada only. I installed three new filter condensers, to replace the double section twist can below and the single 500 volt unit above the chassis, all three fit below the chassis and the set plays with zero hum. I changed yet another resistor, a 2200 ohm unit in series with a .05 mf condenser which was used for bass boost, I took care of this after discovering a touchy solder joint somewhere under the 50L6 power output tube.
I then decided to align the IFs, in spite of what the Philco service literature said the IF frequency is not 460 Kc for this radio it is 455 kc, I discovered this error after attempting to set it at 46O kc and the sensitivity dropped. The proper IF frequency is marked on the sides of the IF cans themselves, when I set them to 455 kc the set perked right up, this is a little hot rod considering it only has five tubes, I wonder if the 7A8 converter has something to do with it? I will deal with the oscillator and antenna alignments next since the stations are a bit off, but I am cleaning the chassis right now so I will get to that in a few days. There is also some paint lifting off the top edge of the dial glass, it is out of sight but I will need to figure out how to glue that back down to stop it from getting worse, a bit of lacquer between perhaps?
Best Regards
Arran
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Aran on the lifting issue on the dial glass you could use paint masking tape (blue) and tape up the front of the glass and then use clear spray lacquer to coat the back. I would take a bit and try it on an area that is out of sight to make sure the lacquer doesn't do something strange before coating the entire surface. You may even lay something over the open area on the back if you don't want to spray that area, basically just coating the outer edges. I have done this in the past to seal any lifting issues.
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I have done the lacquer spray on a couple of dials and it has worked OK. I gave mine a couple of light coats rather than a heavy one. I remember that on the ARF at one time someone mentioned that Jukebox restorers use something made for this. They use it on the painted glass that is getting flakey. I will keep my eye out, as I may have written the name down of the product.
I also have recently acquired a canadian model 84. Its in perfect condition and runs fine. This is a flea market find and has seen a little work done to it but nothing to change its original character.
I am very new to tube radios and I am having some difficulty in defining the age of this unit. I wonder if someone could help me.
The info I have is that its a model 84 made in canada, which is stamped on a metal plate.
I have posted a couple of pics if it helps.
Note from site admin: Sorry, but the photos which were attached to this post are no longer available.
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