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

Testing a Bias Resistor
#1

I'm working on a Philco 37-630T that has a "bias resistor" that looks like a 3 section series (candohm like) resistor.
My question is , how do I test this resistor ? Does one end of the meters probe go to ground and them I measure the resistance on each lug?  Or do I test section to section?
#2

Normally you think of a candohm as being 3 resistors in series. You measure resistance between each lug and the lug next to it. You might have to check out the wiring to see which pair of lugs represents which resistor value on your schematic. Often for bias resistors, one end lug is wired to ground (and the minus side of the output filter cap) and the other end lug goes to the center tap of the power transformer, but I'm not looking at your schematic. Yours might be different.

John Honeycutt
#3

Hi and welcome,
Service info can be found here  http://www.audiophool.com/Philco.html
Nostagair skipped it.

>how do I test this resistor ? Does one end of the meters probe go to ground and them I measure the resistance on each lug?  Or do I test section to section? 
Typically you would want to test each section. In some instants they have been known to short to the chassis when hot. If this happens it causes the - bias voltages to go away. You can just check to see if the - voltage are correct.

GL

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!

Terry




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
A Marconi model 86
Yeah. I am dreading the thought of what to do with all my consoles when I will no longer be able to move them around. I...morzh — 02:51 PM
1947 Silvertone 7086 Wire Recorder/Phono/Radio on YouTube
Cool gadget, Buzz. I took me a couple of second to undestand that that oscillating thing makes the wire to spool correc...morzh — 02:50 PM
A Marconi model 86
My back hurts already, you could build a house with all the wood. PaulPaul Philco322 — 02:49 PM
1947 Silvertone 7086 Wire Recorder/Phono/Radio on YouTube
Part 4 of this series now uploaded link below to anyone interested Buzz — 02:39 PM
Philco model 60
Welcome to the Phorum, Radios1340!  The oscillator coil on the 60 is a common culprit.  I just bought a 60B (June 1934) ...GarySP — 02:33 PM
Philco model 60
Yes, standard alignment procedure. I can get the minuscule tone to vary when adjusting the trimmers. But you almost have...Radios1340 — 01:40 PM
A Marconi model 86
An imposing-looking radio, for sure.morzh — 12:43 PM
Philco model 60
Model 60 struck again :lol: Welcome to the Phorum! Above is the article on Model 60. Could be of some use. Now...morzh — 12:38 PM
A Marconi model 86
Ooh, very nice!jrblasde — 12:19 PM
A Marconi model 86
I am picking up this radio today. The seller tells me it is all there and working.including the tuning eye. It has 13 tu...Dan Walker — 12:07 PM

[-]
Who's Online
There are currently 8703 online users. [Complete List]
» 2 Member(s) | 8701 Guest(s)
AvatarAvatar

>