Thread Rating:
  • 2 Vote(s) - 2.5 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 40-140 Field Coil Replacement
#4

No, just that there would be need to increase the filter capacitor value after the first resistor to minimize hum. Long ago chokes were cheaper than filter capacitors, and permanent magnets did not exist. What we want is a smooth DC curent for the set. So the smoothing capacitors must be a little larger, first one not more than 20% of original, second one not more than 30% of original nominal value. OK and preferred to use much higher voltage values. Observe polarity!


Messages In This Thread
Philco 40-140 Field Coil Replacement - by radiola - 09-04-2012, 11:21 PM
RE: Philco 40-140 Field Coil Replacement - by codefox1 - 09-06-2012, 01:09 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Bakelite crack repair - what is best epoxy?
Thanks everyone. I appreciate you sharing your experience and looks like I'll work with the 24 hr two part clear epoxy....de371 — 10:25 PM
Jackson 665 j2 schematic request
Without a schematic its going to be hard tracing the wire wound spool resistors.daveone23 — 05:21 PM
Jackson 665 j2 schematic request
Looking for a schematic for the 665 j2 multimeter.daveone23 — 04:42 PM
Looking for place to donate unique Philco Philco J-1930 Prototype
>>I'll write to the Henry Ford. I heard, his secretary answers his mail, not he himself.morzh — 12:15 PM
Philco 48-200 alignment questions
Just checked the power cord and I did in fact wire it so the hot side (small prong) goes to the switch.transitony — 11:52 AM
Looking for place to donate unique Philco Philco J-1930 Prototype
Thanks for the suggestions.  I'll write to the Henry Ford.   That would certainly make sense since by the time this prod...jeibner — 11:49 AM
Looking for place to donate unique Philco Philco J-1930 Prototype
For what it's worth, the Henry Ford Museum and Greenfield Village in Dearborn, Michigan may be an option. The obvious ...GarySP — 11:39 AM
Help with Readrite 410 tube tester
Mike and I just had a short discussion yesterday about this very subject. So often it's the connections. Ya gotta have t...RodB — 10:08 AM
Looking for place to donate unique Philco Philco J-1930 Prototype
We have a regional museum here in the Twin Cities called The Pavek Museum. They have an extensive collection of communic...RodB — 09:30 AM
Philco 89B code 123 newbie
I did some nosing around and found that the original caps were 4 3/4" long x 1 5/16" in dia. Guess what 1"...Radioroslyn — 09:28 AM

[-]
Who's Online
There are currently 3461 online users. [Complete List]
» 1 Member(s) | 3460 Guest(s)
Avatar

>