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

40-150 burned resistor
#11

All caps in this circuit are new (when I recapped 5 years ago.) I left a couple of original micas elsewhere, but not here. I also replaced all the rubber wiring.

When I started this thread I pulled off one lead of each cap and resistor T A Forbes suggested and tested for leakage with a vacuum tube capacitor tester at 600 VDC for the polys and 500 for the mica. None leaked under that test, so I reconnected them. Like I said, the current through the resistor is steady at about .4 ma, dissipating about .08 watts. It is a one watt resistor, and it's cool to the touch after running a while.

Just for fun I put replaced the burned one with 2 resistors in series (a 2200 ohm and a 2400 ohm to give 4600 ohm) to effectively make a 2 watt resistor, and I ran the radio for hours and hours over a couple of days monitoring voltage drop, current, and temperature (by the finger method). Everything was dead on every time I checked it, so I'm pretty satisfied that I might have burned the resistor by touching something wrong with a meter lead or something silly like that when I recapped and tested the the thing a long time ago.

I do remember that when I got the radio somebody had totally bollixed it trying to recap & rewire it before I got it. A lot of wiring was missing or just wrong. I made some mistakes trying to straighten our his faulty wiring (gave me fits for a couple of weeks because I had to figure out routing and connections without referring to the original) so maybe I did something to stress that resistor when I was working on it. I just wanted to ask you guys if I'd missed something essential.

Thanks, Gary, Ron, Codefox, and TA Forbes for your responses.

John Honeycutt


Messages In This Thread
40-150 burned resistor - by Raleigh - 02-27-2013, 10:56 PM
RE: 40-150 burned resistor - by TA Forbes - 02-28-2013, 01:05 PM
RE: 40-150 burned resistor - by codefox1 - 02-28-2013, 01:31 PM
RE: 40-150 burned resistor - by Raleigh - 02-28-2013, 09:10 PM
RE: 40-150 burned resistor - by Raleigh - 03-01-2013, 01:11 AM
RE: 40-150 burned resistor - by TA Forbes - 03-01-2013, 02:45 PM
RE: 40-150 burned resistor - by Ron Ramirez - 03-01-2013, 05:19 PM
RE: 40-150 burned resistor - by Raleigh - 03-03-2013, 12:23 AM
RE: 40-150 burned resistor - by gary rabbitt - 03-07-2013, 06:55 PM
RE: 40-150 burned resistor - by codefox1 - 03-07-2013, 07:27 PM
RE: 40-150 burned resistor - by Raleigh - 03-13-2013, 01:35 AM



Users browsing this thread:
[-]
Recent Posts
Philco 42-345 Restoration/Repair
Yes, 57 is an electrolytic cap that should be 12 mfd 400 volts according to the parts list from the Phorum library schem...RodB — 06:01 PM
Philco 42-345 Restoration/Repair
Looks like if I am reading it correctly it looks like the silver capacitor#57 that appears to be a replacement is of a l...osanders0311 — 05:09 PM
Philco model 38 code 121 not receiving signal.
Thanks Arran. Yeah this plastic is pretty thin. It's a little thinner than the original stuff. It kinda reminds me of p...Stormlord5500 — 04:37 PM
Testing a speaker and output transformer Trutone A2-G
The equivalent of one short turn is basically the same as that of a shorted load. If it is the primary's turn, then the ...morzh — 03:53 PM
Testing a speaker and output transformer Trutone A2-G
I've never had an output transformer become shorted, the failure mode is usually an open primary, or in a center tapped ...Arran — 03:52 PM
Philco model 38 code 121 not receiving signal.
As long as the plastic sheeting isn't too thick, I think that the thickness of photographic film would be just about rig...Arran — 03:19 PM
Philco model 38 code 121 not receiving signal.
Well why not! :lol:Stormlord5500 — 03:14 PM
Philco model 38 code 121 not receiving signal.
Good luck next thing you know you will be winding coils just for the fun of it. DavidDavid — 11:29 AM
Testing a speaker and output transformer Trutone A2-G
morzh Short-circuited turns can be considered as a half-dead transformer. But on this case transformer will hot and s...Vlad95 — 11:01 AM
Testing a speaker and output transformer Trutone A2-G
I am not sure how a transformer could be weak. It could be inadequate, but only when you replace the original with somet...morzh — 09:56 AM

[-]
Who's Online
There are currently 2251 online users. [Complete List]
» 1 Member(s) | 2250 Guest(s)
Avatar

>