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

An Introduction and a Philco 90 issue.
#44

I'm not sure what is going on here. With the speaker unplugged we are reading the resistance of resistors 49 and 50. with the speaker plugged in we seem to be reading the speaker field coil but I don't understand how. The number 4 wire connects to the upper end of the coil but the lower end of the coil should nowhere be connected to chassis ground, that is why I suspected a shorted filter cap. Maybe someone will jump in and help us here. CALLING TERRY! ....... ANYONE!
For now let's move to the terminal 3 wire. We have zero ohms here, should be infinity. Looking at the schematic, you can see this wire connects only to the cathodes of several tubes and should not have any connection to chassis ground. Trace this circuit looking for an error.

Steve

M R Radios   C M Tubes


Messages In This Thread
An Introduction and a Philco 90 issue. - by cknob - 11-23-2021, 09:20 PM
RE: An Introduction and a Philco 90 issue. - by Steve Davis - 11-27-2021, 01:05 PM



Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
PT 6 chassis screws size???
Hello bridKarl, that sounds right or maybe 8/32 . Sincerely Richardradiorich — 01:00 AM
PT 6 chassis screws size???
Have this done except for missing chassis screws. It looks like 1 inch 6/32 sheet metal screw may work but can anyone s...bridkarl — 10:32 PM
Philco model 38 code 121 not receiving signal.
Hello Stormlord, Well done on rewinding that coil it turned fairly good for your first one. Sincerely Richardradiorich — 09:12 PM
Philco model 38 code 121 not receiving signal.
Well here it is. It ain't pretty, but hopefully it'll work. I checked it with my DMM on continuity and it keeps and r...Stormlord5500 — 08:56 PM
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

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

>