Just got my 2nd radio, a Philco 39-7 in very good physical condition.
The only things I see wrong with it at the moment are the scratchy volume control and the tuner needle is slightly misshapen.
The needle itself is not perfectly straight, but from where the post is in the center, one "leg" of the needle is straight, the other bows inward slightly. Since the shaft itself is also not perfectly straight, one side of the needle will contact the paper on the dial depending on the tuner position, which is not really desired.
What would be the best way to straighten the shaft and tuner needle? I could simply try to re-bend it, but I do not want to do anything to risk breaking the tuner needle.
Additionally, the person who partially restored it before I got ahold of it (it was in working condition) seems to have only recapped the power supply portion. There are still wax-covered paper caps in the radio.
even more - I was planning on using my 39-6 as a template along with the schematic. Somehow these two radios are more different than I was lead to believe by the schematic. Mainly, there are the presence of the following: ANT and OSC Transformer. There's also a disconnected wire (black) leading from the I.F. Trans. that is dangling from the underside. I have no idea where it should go, since it looks like it was connected to Oscillator transformer by the position and length of the wire.
For the switch/volume - is there a simple modern replacement for this?
I disassembled and cleaned it with contact cleaner, but it looks like someone was in there already based upon how the tabs looked and I no longer trust it.
Got a variac and a schematic and got into the guts of this yesterday. Three immediate problems:
1. Volume knob was scratchy. Needed disassembly to clean with DeOxit, that worked, but the power switch never worked again. I did get a modern replacement that went in fine.
2. The 0.01uf wax cap on the volume control fell off. This was replaced with a modern cap, all I had on hand was a mylar capacitor, should this be replaced with an electrolytic, or will this be fine?
3. A wire was dangling off of the I.F. trans assembly. After sweating over the schematic, I found its old location and reconnected it.
All else looked good, except one green wire started flaking off insultation material. Since I had it off anyway fixing the volume, I sealed it in shrink tubing.
The person who had this before me cleaned up the case real nice. They also replaced all the caps on the power side. There's still 3-4 wax caps in it that I need to get to.
I did bring it up on the variac slowly with no signs of a problem. At approx 80VAC the speaker started making static, a bit higher and a station was coming in loud and clear! It's not smoking either!
So I reassembled it and looked it over - it tunes great, sounds great except for some slight hum/buzz that changes with volume. I have it next to its sibling 39-6 I posted about earlier and know I know the speaker in the 39-6 needs to be re-coned.
Next up on this is figuring out what rubber spacers are needed for the pushbutton tuning assembly, swapping out the remaining wax caps. I also need to get a polarized plug and put a fuse on it.
Still, this is my first electrical repair and I'm quite pleased I was able to figure it out myself. After I wrap this one up, I'll tackle something a bit more difficult.
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rworne, very nice job and congratulations on you first radio! If your like the rest of us, you will be starting another. We are glad to have you on board.
Jerry
Thanks Jerry,
This is actually my second. It's sitting on my first one. I posted about it earlier about not tuning the whole range - due to a stiff tuning capacitor and a slipping dial cord. I was getting rather miffed at the restoration job that was done on it until I looked at the one I currently have. The restorer of the 39-6 replaced all the caps, added a polarized plug and fuse, and also removed all the old flaky wiring and replaced it with new insulated wiring. I am quite confident this radio won't burn the house down.
So at least I know he did a good job on the electrical part. That's flawless. I have issues with other parts of the restoration - a re-veneering of the case and the speaker that was not really restorable.
But today I am a lot wiser and know what to look for.
Jerry,
Did this model still have bakelite caps in it?
Brenda I believe you wanted to direct your question to the OP. I don't have the radio in question. Monsoon season here, how is the weather over yonder?
Regards, Jerry
No bakelite capacitors from what I see. Two large "cans" for electrolytic. Some tubular capacitors that are polarized (at least that's what the black stripe implies to me), a silver-mica capacitor - that's about it. I'm trying to determine if replacing the tubular caps with a mylar film capacitor is OK.
Yes as long as the tubular is a paper cap, a film cap is OK to replace it.
Worne, those tubular wax caps are not really polarized caps (like electrolytics). Don't worry about the black bands as the replacements go in either way. As Mortz indicated just regular poly type cheap 630V caps to replace.
Jerry
Yup, 630V are the ones I'm using. Great! I'll get the rest of them swapped out this weekend.
May I ask from whom, or where, you acquired this radio? If it's from whom I think it is It would explain a lot of the problems you have been having.
Regards
Arran
The 39-7? It came from eBay. Not all the problems are the fault of who I got it from. While it was listed as "restored", it was actually partially done - the really important caps were replaced. It worked fine upon arrival - aside from the scratchy volume. My removing the volume pot it to get it cleaned caused the other issues. Which seller of which radio is the concern: the 39-6 or the 39-7? The 39-6 was purchased locally from a restorer that has been around for 15+ years.
I'm getting better at knowing where to look and what to look for... but if there's anyone I should watch out for, I want to know - I am looking for a very good condition Zenith console (I don't want to muck with it myself, I'm horrible with woodwork) and don't want to get burned. I only know of two people in So Cal that do restorations on these.
I'm actually pleased to some extent the 39-7 has these minor issues, far easier for me to cut my teeth on a unit like this than something totally toasted. I've learned a lot in the past couple of months I've been messing with these and don't want to tackle too big of a job at the start.
Everything I have come across one my own has been total junk and priced way more than the units I see all the time on-line. Here in So Cal I see plenty of dodgy 1940-50's type radios with missing buttons/parts, frayed cords and cracked bakelite cases with missing chunks sold "as-is" for $200.
My advice is to search Ebay and Craigslist for Zenith consoles that are within driving distance to your home. Most Ebay consoles are listed as "local pickup only", then email the seller and go examine the radio before you bid or spend any money.
PuhPow:
That's what I plan on doing. I found someone in OC who advertises on CL and you call him up and schedule an appointment where you can audition units he restored. He seems to do good work too.
The other person I know used to have a store in the OC area and now sells exclusively at the Rose Bowl Flea Market.
Back to the 39-7, I recapped the remaining paper caps and the radio survived. I also found out the previous owner was kind enough to rewire the power so that the switch comes first - yet there's no polarized plug.
I also found the safety cap. It's still original - a dark brown domino looking thing connecting one of the AC lines to ground. I assume I should remove this and replace it with a modern one?
That old cap is just a regular wax/paper cap. It needs to be replaced with a y type safety cap.
Ive got a 39-7 in my queue. Very classy looking radio. Im just a bit tired of dealing with rubber wiring after just finishing a RCA C8-19 console. It seems these rubber wire sets gravitate towards me!