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

37-620 Plate Resistor?
#2

That resistor looks like a decoupling resistor, used to isolate the power supply of the IF stage from the converter and RF stages. Sometimes if B+ power is applied to all stages from the same source, you may get instability or oscillations due to the common power source. The resistor, together with a bypass cap serves to filter the supply and isolate the stages from each other preventing the problem.

Most likely, the 10K value on the schematic was a typo, all to common on the Philco schematics. The plates of the 6K7 and 6A8 probably draw about 10 mA total, so there would be a voltage drop of 10 volts or so across 1K which seems reasonable. A 10K would give 100V of drop which would clearly be excessive.


Messages In This Thread
37-620 Plate Resistor? - by Vic Gibson - 08-30-2013, 09:21 AM
RE: 37-620 Plate Resistor? - by Mondial - 08-30-2013, 03:19 PM
RE: 37-620 Plate Resistor? - by Arran - 08-30-2013, 11:01 PM
RE: 37-620 Plate Resistor? - by Vic Gibson - 08-31-2013, 09:54 AM
RE: 37-620 Plate Resistor? - by codefox1 - 08-31-2013, 10:39 AM



Users browsing this thread:
[-]
Recent Posts
Philco model 38 code 121 not receiving signal.
I think this thing is way more accurate than my Walmart DMM. :DStormlord5500 — 08:19 AM
Philco model 38 code 121 not receiving signal.
Thankyou for the kind words sir. I double checked it with my component tester and it read 2.7 ohms at .02mH.Stormlord5500 — 08:14 AM
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

[-]
Who's Online
There are currently 749 online users. [Complete List]
» 1 Member(s) | 748 Guest(s)
Avatar

>