Philco model 39-71

[w2amr]

My friend picked this up for me at a yard sale. 1938/39 Philco battery powered portable . This was Philco's first battery powered portable.
161301613116132

[AA1OH]

90 volts b supply and 1.5 volts a supply. Looks very clean. good find, now for a trip to Harbor Freight to get a bunch of 9 volt batteries for the b supply. At least you do not have to worry about filter caps going bad.

[AA1OH]

There are battery AC substitutes from that vintage you could keep an I out for but then it will not be portable. I had great fun with a 6 volt Philco farm radio (floor model) that I played at car shows in my 50 Chrysler (6 volt car).

[KG4CGC]

She's a beaut!

[WZ7U]

Nice! You have a good friend indeed.

[w2amr]

According to the schematic, it used two 45 volt batteries in series for the B+. I have a Hewlett-packard variable B+ supply to get my 90 volts, and I can use a d cell battery for the filaments. , just to get it up and running.

[N8YX]

That's going to be a nice set when you refinish it.

Thanks for sharing!

[kb2vxa]

The reason for 2 45V batteries in series was they lasted longer than a 90V B battery that incidentally had the same contact types as a 9V transistor radio battery only larger. The 45V and 1.5V batteries ere a little larger than half bricks, that's why there is so much room behind the speaker. It uses a 1A7 pentagrid converter, a 1N5 pentode IF, 1H5 diode/triode detector/AVC and 1st audio, all .05A filaments and a 1C5 power pentode .1A filament audio output with a total current drain of .25A so you see why a D cell was not used, but rather a much larger A battery.

DO NOT refinish it, DO NOT change a thing! It barely has a few minor dings that don't detract from its appearance. Anything in the original factory finish in that near perfect condition is worth more than ANYTHING else, simply stated if you refinish it you will ruin its collector value, it will be worth little. I used to repair radios and TVs including antiques and had a fair collection of original parts and working antique tubes as part of the business. I had plenty of octal 6V tubes with grid caps, but I've never even seen 1V octal tubes. Those must be rare as hen's teeth, I would only see if the radio works and I'm reasonably sure it does, and never turn it on again for fear of a burned out filament in a tube that cannot be replaced. All of my 1V and 3V tubes were 7 pin miniature based used in series string "house current"/battery portables that used 7.5V A batteries and 90V B batteries like the Admiral given to me by grandpa. The beauty of it was the ferrite loopstick in the rotatable part of the handle you could turn for best reception without turning the whole radio.

16134

[w2amr]

Thanks for the comments guys. It has 5 waxed paper caps and one 3MFD electrolytic . They have been removed and i am awaiting replacements from antique electronic supply. I also ordered a new plastic dial cover. We're moving along.

[kb2vxa]

Oh no, those paper caps are likely still good despite their age not having been subject to much voltage or high temperature. The electrolytic is questionable, sometimes they dry out, sometimes they don't. Antique Electronic Supply is a good source if you're restoring an antique, knobs, wood stain, grille cloth, toobz, stuff to make a wreck look like new, but I wouldn't be in a headlong rush to "re-cap" a radio like some do just because they're old. The idea when dealing with any antique is to keep it as original as possible so you don't ruin the collector value. Another thing that goes hand in hand is never irreversibly modify a radio. That's why whenever I "solid stated" rectifiers from an R-390 to a couple of broadcast transmitters I always smashed old tubes and used the bases to make plug in silicon stacks.

Good luck with the project, different strokes for different folks I suppose. A question came up the back of my neck and lodged itself in my brain. Why are you coming along? Is there something wrong with the radio so it requires work? OK, that's two questions because what I would do is power it up and measure all the socket voltages to make sure something isn't way out of line. If it works and everything looks OK I'd go no farther, all original in working condition is most valuable of all.

BTW that red tabby reminds me of my Little Face, Face for short. RIP kitty.

[w2amr]

SOP. I don't screw around with 80 years old paper or electrolytic capacitors. Change them now, and never have to worrying about them failing. If it works, Don't turn it on again? That's like having a classic car that never gets started. No thanks, It will be used a lot, just like all my other radios. BTW, the filaments in this radio are wired in parallel.

[w2amr]

It's Alive! :dance:

https://www.flickr.com/photos/42112824@N00/40476504953/in/dateposted-public/

[WZ7U]

It's Alive! :dance:

https://www.flickr.com/photos/42112824@N00/40476504953/in/dateposted-public/

AWESOME!!!!!!

[kb2vxa]

"SOP. I don't screw around with 80 years old paper or electrolytic capacitors."
When you get to be 80 years old will you be a leaky paper cap or a dried out electrolytic? (;->) I see you're not a collector nor interested in somewhere down the line selling it to a collector, nor even donating it to a museum eventually. It's nice to listen to 80 year old broadcasts... oh, that was The Twilight Zone... but what will you do when one of those 1V filaments burns open? Where will you find a replacement?

Oh I know it's a current hog with parallel filaments. That's why I mentioned a d cell would go flat quickly. Same thing with B+ from 2 45V batteries in series, the first portable radios used big batteries that made them rather heavy, about the same as your average boom box.

Classic cars, interesting you brought that up. There are two kinds of museums, Harrah's with static displays, and then there is Jay Leno.

[w2amr]

So do you have a room full of radios that don't work because you can't replace any components ?
BTW, follow this link to buy all the 1V tubes you want.
https://www.etsy.com/listing/674674148/rca-1h5-1h5gt-tube-vacuum-tube-ampoule?gpla=1&gao=1&utm_campaign=shopping_us_Lowtechelec_sfc_osa&utm_medium=cpc&utm_source=google&utm_custom1=0&utm_content=12300058&gclid=CjwKCAjwm-fkBRBBEiwA966fZBijw9q3FJslp_yzy-MaVw2kaaLAHGQtHdLSppKECuX2jWrRgOLSJBoCiKkQAvD_BwE