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

Thread Closed

Philco 40-185 - Help Needed
#1

I acquired a philco 40-185 recently in original condition.  The previous owner said he plugged it in and the light came on but it hummed.  I brought it home and took the chassis out.  (This is my second restoration.)  

nyway, I replaced all the old paper caps and the two electrolytics (and a few resistors that tested badly).   I added a fast blow inline fuse.  I replaced the AC line with a modern cord.  I rebuilt the bakelite block with two .01 mfd safety caps.

I have it all put back together and tested it with a dim bulb tester, but no dial lamp and no light at all on the “dim bulb”.  I can confirm there is 120v coming in the main (hot) line which enters the chassis, goes across the fuse then to the bakelite block, then to the on-off switch and back to the AC transformer.  There is 120v all the way to the transformer line on the on-off switch.  The neutral goes directly to a bakelite block.  No tubes are glowing.  No dial light.

Now, I’m stuck.  What should I look for next to determine the problem?
#2

Hi And Welcome,
Would measure the resistance across the primary of the power transformer. Should see a low resistance.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!

Terry
#3

Test the transformer primaries for an open...
#4

got 10.1 Ohms across the two primary wires
#5

Thanks for your help!  Your replies helped me locate the problem.  I had one side of the primary connected on the wrong terminal of the bakelite block.  Working very well now!
#6

Hi Doc,
Glad you figured the connections out. I have done about 3 of the 40-185 radios. But as with any resto job you do, it pays to make several photos of the chassis wiring before you start. I still do, and has saved me many times.

 I know we all have our methods of recapping, and of course the paper caps need to be replaced along with the electrolytics.  i personally do all the basic tests first, field coil, transformer with tubes pulled, visual inspection, tube tests. Then I replace the filter caps first, as they are most critical. Then I do a very brief 35-45 second powerup, having the radio pre tuned to a local station. As soon as I hear a station I will power down.  If no stations, but no hum then I will continue to replace a couple paper caps at a time, test again.   The reason is that if you have a working set, and suddenly after a couple caps it is dead, you know right where to look for the trouble. If you replace 15-25 caps all at once and it's dead, you have a harder time to figure out where you may have made a mistake.
Good luck to you and your new hobby!! Gary.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 71 Code 125
Ok guys. Thanks for the input. As for AI this is why I ask the experts. Dandconant — 07:39 AM
Philco 71 Code 125
Technically, that's C-. B- is chassis ground. The resistor between chassis ground and the HV center tap makes the HV c...MrFixr55 — 11:24 PM
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

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

>