Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x


[split] Philco 1938 Farm Radio
#2

Hi Mt MattKing,

Here is a link to the schematic. It was buried early in the thread, but I am happy to attach it here.

https://philcoradio.com/library/download...l.%201.pdf

Yes, you need 135VDC, 67.5VDC B+ (Neg to chassis), +2VDC (Yes, 2 Volts, Neg to chassis), and "C-", 3V and 7.5V, (Pos to chassis)

For 2V, it would be best to obtain a 3V, 1A "Wall Wart" power supply. Here is a reprint of my previous post about running the filaments on 3V:

The A supply will be the most difficult because you need the most current (500 mA 0r 0.5A) at 2.0V. Since "D" size dry cells provide 1.5V and 2 in series provide 3V, you need to calculate the dropping resistor needed. The good news, is that I am going to do that for you right now:
Below is a chart with each tube in your radio and the current it draws:

1A6 0.060A
32 0.060A
32 0.060A
30 0.060A
19 0.260A

Since these tubes are all connected in parallel, the total draw is 0.5A. Since a resistor has to be added in series to the A Battery connection to the radio to drop the voltage to 2.0V, and current is constant in a series circuit, we need to calculate the resistance needed to drop 1V at 0.5A. So if E=IR then R= E/I. So, if the voltage drop is 1V and the current is 0.5A, then R = 1/0.5 or 2 Ohm. Since the current is constant, in theory a 2 Ohm 1/2 watt resistor is sufficient, use a 2 Ohm resistor at 2 Watt or higher rating.

Since a D Cell delivers only about 1.5Amp Hours, 2 D Cells in series will last 3 hours or less running this radio. 3V 1000 MA "Wall Wart" power supplies can be found for $15.00 or less on the internet. This and the 2 Ohm 2 Watt resistor will power your filaments.

"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis

Best Regards, 

MrFixr55


Messages In This Thread
[split] Philco 1938 Farm Radio - by Mtmattking - 02-17-2026, 11:19 PM
RE: [split] Philco 1938 Farm Radio - by MrFixr55 - 03-10-2026, 09:50 AM
RE: [split] Philco 1938 Farm Radio - by morzh - 03-10-2026, 07:18 PM
RE: [split] Philco 1938 Farm Radio - by Arran - 03-11-2026, 05:28 AM
RE: Philco 1938 Farm Radio - by MrFixr55 - 02-18-2026, 08:46 AM
RE: Philco 1938 Farm Radio - by Mtmattking - 02-18-2026, 08:42 PM
RE: Philco 1938 Farm Radio - by Mtmattking - 02-19-2026, 07:54 PM
RE: Philco 1938 Farm Radio - by MrFixr55 - 02-20-2026, 09:28 AM
RE: Philco 1938 Farm Radio - by MrFixr55 - 02-20-2026, 10:06 AM
RE: Philco 1938 Farm Radio - by Arran - 03-01-2026, 07:29 PM
RE: Philco 1938 Farm Radio - by Mtmattking - 03-03-2026, 04:19 PM
RE: Philco 1938 Farm Radio - by Arran - 03-03-2026, 09:43 PM
RE: Philco 1938 Farm Radio - by Mtmattking - 03-03-2026, 09:58 PM
RE: Philco 1938 Farm Radio - by Arran - 03-04-2026, 12:25 AM
RE: Philco 1938 Farm Radio - by morzh - 03-04-2026, 10:49 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
54C Cabinet Refinish
hello Roy, I’d follow Arran’s suggestion and use automotive gasket material, which I keep around for situations like th...radiorich — 10:22 PM
Philco 71 Code 125
This might be one of those cases where it's a ground to an AC voltage and B- to DC.RodB — 08:22 PM
Philco 71 Code 125
Really Rod? I know you would not steer me wrong but AI say this is a short circuit? What if I moved the 6 volt center ta...dconant — 06:40 PM
54C Cabinet Refinish
Roy; Personally I would have left the asbestos alone if it were my set, but you can find a modern substitute that som...Arran — 04:51 PM
Philco 71 Code 125
Looks like that might be the B- buss, so that would be correct.RodB — 01:32 PM
Philco 71 Code 125
I noticed on the code 121 schematic the center tap for the 6 volt winding and hv winding are tied together. Is this corr...dconant — 12:16 PM
Philco 45-6365 Universal IFT Instruction Manual
The Philco Parts Catalog for 1942 shows it as usable for 175 kHz, 260 kHz, and 465 kHz. The instructions will show how t...DaleHCook — 11:19 AM
Stromberg Carlson 1500 Squeal
Hello Rob, I agree with you—I have one here at my house that I need to check out. It’s way over-engineered just to make...radiorich — 11:05 AM
My Atwater Kent 84
Well getting around to restoring my AK84. Mike was a big part in me being able to snatch this one a few years ago. I won...462ron — 10:57 AM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
The engine is a B&S 23 inch cast Iron holds 2 quarts of oil. The Generator is a 4 pole 1800 rpm mine was made in 195...David — 10:51 AM

[-]
Who's Online
There are currently no members online.

>