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Philco 39-30 restoration - Printable Version

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Re: Philco 39-30 restoration - Ron Ramirez - 02-08-2012

Well, as I'm sure you know, Philco didn't always print their production changes. That's what makes restoring these things such a challenge sometimes. Icon_wink Icon_confused Icon_crazy

Re: Philco 39-30 restoration - RGallahue - 02-08-2012

Bob,

Is it typically necessary to reseal the transformers with wax, and if so, what wax did you use?

I ask because I will probably be doing some similar work in the future.

Thanks,
Richard

Re: Philco 39-30 restoration - Bob Andersen - 02-08-2012

Ron Ramirez Wrote:Well, as I'm sure you know, Philco didn't always print their production changes. That's what makes restoring these things such a challenge sometimes. Icon_wink Icon_confused Icon_crazy

Yes indeed. I can't wait to dig into my much more complex 15DX and 37-10 consoles ;)

RGallahue Wrote:Bob,

Is it typically necessary to reseal the transformers with wax, and if so, what wax did you use?

I ask because I will probably be doing some similar work in the future.

Thanks,
Richard


I'm no expert, but it seems like a good idea as it holds the wires in places and keeps moisture out. It's also easy to melt out if another repair is necessary unlike glue.

I used micro-crystaline wax. Here's the thread where the topic was discussed.

I imagine beeswax or sculpture wax would work OK too. Just don't use use fragrant beeswax from a honey supplier like I did once. That radio still smells like honey Icon_smile

Re: Philco 39-30 restoration - Bob Andersen - 02-10-2012

I've moved on to restuffing the paper caps. I use a heat gun on low to melt out the insides. Then, slide in a new cap. and seal the ends with brown hot glue.
One done - about a dozen to go.

[Image: http://farm8.staticflickr.com/7004/6850023263_e129c737e8_z.jpg]

RE: Philco 39-30 restoration - Bob Andersen - 02-27-2012

I finally finished the recap and fired it up for the first time.
Once the radio is working, I'll mount those electrolytic caps more securely.
[Image: http://farm8.staticflickr.com/7196/6784769546_2ca0714ef3_z.jpg] [Image: http://farm8.staticflickr.com/7198/6784769718_0be6416500_z.jpg]
At first it was howling with feedback then I realized I forgot to reinstall the 75 tube shield.

It's working fairly well on both AM and SW, but not as much gain as I expected. Next, I'll double check all the voltages and do an alignment.

RE: Philco 39-30 restoration - Bob Andersen - 02-27-2012

I couldn't get the presets to work properly and eventually found this bad 370 pF mica cap (#10 on the schematic).
It works with the adjustable coils to set the LO oscillator frequency.

[Image: http://farm8.staticflickr.com/7067/6934208203_6ee524bce9_z.jpg]

Each preset slug only covers a portion of the BC band as shown on the chassis.
[Image: http://farm8.staticflickr.com/7048/6934229439_4fd18d8250_z.jpg]

Replacing it with a 390pF got the presets working, but I couldn't tune below 800 kHz on the first four presets. I bumped it up to 500 pF which go me down to 680 kHz.

I suppose I could increase the capacitance even more, but I'd like to know why the tuning range is so far off ?
[Image: http://farm8.staticflickr.com/7178/6788094356_21c291e752_z.jpg]

RE: Philco 39-30 restoration - Bob Andersen - 02-27-2012

I bumped the capacitance up on cap #11 by 100pF and that got me right down to 550 kHz.

Meanwhile, I'm moving on the the cabinet. The only really issue it has is crummy decals.
I'm very carefully sanding off the old ones, then I'll give the whole cabinet a light 320 grit sanding. Next, a little Howard's walnut ARF to refresh the color a bit.
Then apply the repro. decals and, finally, give it a few coats of fresh lacquer.
[Image: http://farm8.staticflickr.com/7059/6934208029_d3f4a69cbb_z.jpg]

The grille cloth and backer was stapled to the inside of the cabinet. Some pliers took care of that.
[Image: http://farm8.staticflickr.com/7069/6936952561_7677e87694_z.jpg]

The cloth is dirty, but intact. I've heard that K2r spot lifter works well. http://www.k2rbrands.com/products/original.htm I'll try to track some down and give it a try.
[Image: http://farm8.staticflickr.com/7193/6790833944_6edf836218_z.jpg]

RE: Philco 39-30 restoration - Ron Ramirez - 02-28-2012

Your 39-30 is coming along very nicely, Bob Icon_thumbup

I don't understand why your pushbuttons would not tune below 800 kc until you changed (11) to 600 pF? Very strange indeed! These caps are always bad and I always replace them just like I would a paper cap, but I generally keep 390 pF micas in stock for this, since 370 isn't a standard value. I haven't had a problem yet like you had, knocking on wood...

One would expect the inductance of the coils in the pushbutton assembly to change a little over the decades, but to change that much is unheard of. Are the pushbutton contacts good and clean? As thorough as you are, I am sure that they are very clean, though.

Sorry...I am at a loss to understand why this happened to your particular set...I hope something doesn't go "pop" later on and you find the lower pushbuttons tuning LW! Icon_eek

RE: Philco 39-30 restoration - Bob Andersen - 02-28-2012

Thanks Ron. I do still have the old #11 cap in the set as it seemed to test OK on my Solar capacitance bridge. I'll order up a nice assortment of new mica caps and replace them both with the same value starting with 390pF.

Let's not speak of anything popping Icon_shh



RE: Philco 39-30 restoration - Arran - 02-29-2012

Maybe the pushbuttons are out of whack because the IF alignment is off, not to surprising given the age of the set and the fact that you had to open up one of the cans to replace the wires and a resistor.
Regards
Arran

RE: Philco 39-30 restoration - Bob Andersen - 03-02-2012

I've had the radio playing for a while and it's starting to act up. Stations fade and static increases after it's been playing 5+ minutes. I'll go through and recheck voltages etc. Maybe one of the old micas caps is acting up ?

Meanwhile, I'm making progress on the cabinet. I filled in all the cracks and chips with lacquer sanding sealer until it was nice and smooth.
One decal has been applied with four more to go.
[Image: http://farm8.staticflickr.com/7203/6947114425_c47b19ca44_z.jpg]

I also picked up some K2r and gave it a try. It's cleaner, not like new, but cleaner for sure.
[Image: http://farm8.staticflickr.com/7049/6801050332_a7a7a192fb.jpg] [Image: http://farm8.staticflickr.com/7192/6801050530_2bcc4204e9.jpg] [Image: http://farm8.staticflickr.com/7039/6801050710_ec7c2c425e.jpg]

RE: Philco 39-30 restoration - Bob Andersen - 03-02-2012

With the help of a guideline, I finished applying all the decals. Not my favorite task at all.
[Image: http://farm8.staticflickr.com/7193/6947396267_661f3b30dc_z.jpg] [Image: http://farm8.staticflickr.com/7061/6947396509_1e2de7d66c_z.jpg]

RE: Philco 39-30 restoration - Bob Andersen - 03-02-2012

(02-29-2012, 01:30 AM)Arran Wrote:  Maybe the pushbuttons are out of whack because the IF alignment is off, not to surprising given the age of the set and the fact that you had to open up one of the cans to replace the wires and a resistor.
Regards
Arran

I just went through the alignment process this evening and, you're right, it was pretty far off. That improved the SW performance noticeably, but the BC band is a mess. There's a very loud buzzing all through the tuning range. I'll have to go digging for the culprit.

RE: Philco 39-30 restoration - Arran - 03-02-2012

(03-02-2012, 05:08 PM)bandersen Wrote:  With the help of a guideline, I finished applying all the decals. Not my favorite task at all.
[Image: http://farm8.staticflickr.com/7193/6947396267_661f3b30dc_z.jpg] [Image: http://farm8.staticflickr.com/7061/6947396509_1e2de7d66c_z.jpg]

I love that zebrano veneer inlay they used on those cabinets, the whitish veneer with the dark stripes. Thankfully Philco used real inlay instead of the fake dynoc stuff like the brand with the big black dial typicaly used, at least on their lower mid priced to high end sets.
Regards
Arran


RE: Philco 39-30 restoration - Bob Andersen - 03-04-2012

I love that inlay too Icon_smile

The radio came with replacement electrolytics. I found the original part #s, did a web search and, amazingly, found someone selling a couple Icon_thumbup

Check out the bulge in the one on the right. I wonder if it was made that way or did that much pressure build up inside ?

I'm going to be restuffing them using Syl's technique.
[Image: http://farm8.staticflickr.com/7204/6951230103_636c5661a4_z.jpg]

I also sprayed on the first coat of gloss lacquer.
[Image: http://farm8.staticflickr.com/7197/6951230277_5983e50d3a_z.jpg]