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

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Field coil on Philco 38-12
#1

I have begun restoring a Philco 38-12 radio and have a question that I hope I can get an answer to on the phorum The speaker in this radio uses a field coil with a resistance of 1.5k ohms according to the schematic. I have completely disconnected the coil from circuit and when I measure the resistance I get approximately 6k ohms on my multimeter. I have been told that the 1.5k ohms shown on the schematic is the impedance of the coil and not the DC resistance. I restored a Philco 39-6 and the schematic showed 1.7k ohms and the coil showed approximately 1.7k +/-. So my question would be, is the coil shorted and needs replacement, or is it ok as it is?
#2

if anything, DC resistance is smaller than the impedance to AC current.

If it says 1.7K, it should measure 1.7K. Not 6K.

A shorted coil would be 0 Ohms, not 6k.

If it measure 6K, it is possible it is a different speaker altogether or the coil is bad.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 42-345 Restoration/Repair
Hi OSanders, Look carefully at the band switch. Turn it slowly and "wiggle" it around the desired band. ...MrFixr55 — 12:33 AM
5U4 vs 5Z4 tubes
I think that RCA and GE introduced metal tubes in the USA in 1936.  I don't know if they were being made by RCA, GE or b...MrFixr55 — 11:20 PM
Philco 42-345 Restoration/Repair
Vlad95, Thank you for the stringing guides and wow there are so manyosanders0311 — 06:01 PM
5U4 vs 5Z4 tubes
A pre war Hallicrafters, and an early one too, very nice! 1936 is pretty early for metal tubes too, which would explain ...Arran — 05:58 PM
Philco 42-345 Restoration/Repair
Thanks Rod, "When you hear the background hiss and no station it usually indicates that the oscillator quit" ...osanders0311 — 05:52 PM
Philco 42-345 Restoration/Repair
RodB :beerchug:Vlad95 — 10:22 AM
Philco 42-345 Restoration/Repair
Vlad, you nailed it. Swiss and German roots.RodB — 09:54 AM
5U4 vs 5Z4 tubes
Well this is a Hallicrafters SX/9 circa 1936. No real issues so far although I dodged a real bullet with a cap that was...bridkarl — 07:59 AM
5U4 vs 5Z4 tubes
The pinout is the same but the 5U4 has a 3 amp filament, verses 2 amps or less on the 5Z4. I think that the pinout of a ...Arran — 12:04 AM
Philco 42-345 Restoration/Repair
By the way. osanders0311 Take a look here: Dial cord stringing Guides May be here you can fount correct string settin...Vlad95 — 11:15 PM

[-]
Who's Online
There are currently 1097 online users. [Complete List]
» 1 Member(s) | 1096 Guest(s)
Avatar

>