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

Philco 16 Code 121 Control Grid Voltages?
#1

I am working on a Philco Model 16 that has been butchered by a previous repairman. The schematic is difficult to read. What are the resistances of Resistor 81? The best I can read is from left to right, 20, 100, and 130.

Also, are the Control Grid voltages correct for the Output tubes ( two 24's ) 34 volts, the Driver tube ( 24 ) 0.6 volt and the 1st A.F tube ( 77 ) 0.4 volts?

Thank you,
nv3g
Oscar
#2

Which version 16 are you working on, Oscar? Code 121, 122 or 123 (5-band), or Code 125, 126 or 127 (4-band)?

--
Ron Ramirez
Ferdinand IN
#3

Sorry. I am working on a Philco Model 16 Code 121. I would expect the bias voltages on the control grids to be negative voltages. I am measuring the voltages from the control grids to chassis ground. The schematic was a little fuzzy and hard to read. I was trying to confirm if I had the resistor 81 resistances correct and if the voltages in the voltage chart were correct.

Thanks for your help.
nv3g
Oscar
#4

Looks like #81 is a 250 ohm resistor with two taps. The first at 20 ohms(from ground) and the second at 120 ohms.
Terry

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
#5

Thank you, Terry. That is what I thought trying to read a blurry schematic. I wonder about the control grid voltages, which are positive in the voltage table. I thought they were negative coming from the negative power supply source. I am looking at the voltage table ( tube socket data ) on the schematic page.

Appreciate the input.

Best Wishes
nv3g
Oscar
#6

The control grid voltages are negative. I am reconstructing the negative bias circuit in the Philco 16 Model 121 radio.
The previous repair person tried to do a make shift repair rather than do it correctly.

Thanks for your help.

nv3g
Oscar




Users browsing this thread: 3 Guest(s)
[-]
Recent Posts
An attempt to remove the Field Coil from a G speaker
Gary I in fact did, on a 38-14, I think, where I had a speaker with the dead coil. Well...it kinda worked. Kinda, be...morzh — 10:38 PM
An attempt to remove the Field Coil from a G speaker
Mike, what ever happened to that plan you had to try using a rare earth magnet to magnetize the pole? This looks like a...GarySP — 10:25 PM
RCA T62 is playing.....
Beautiful set.morzh — 09:07 PM
An attempt to remove the Field Coil from a G speaker
Well....here it is. The green stuff. Unfortunately, probably penetrates deep. I opened the top layer and saw that: ...morzh — 08:58 PM
Philco 91 Restore Code ??
:clap: :clap: :clap: :clap: Really nice workmanship!!! Top of the chassis looks great. Sorry about the long winded e...MrFixr55 — 08:09 PM
Philco 40-120C Restoration
Thank you for your reply. I will check voltages on the other tubes, look at resistor 23 and cap 25, etc. If all else fai...bluecap — 07:58 PM
RCA T62 is playing.....
Nice looking set great save. DavidDavid — 07:48 PM
Philco 89 indicator light.
Hello Jim, I have done several 89s. The trick is to move the drum in or out on it's shaft. You will need to loosen a set...dconant — 07:36 PM
An attempt to remove the Field Coil from a G speaker
MrFixr Yes, it is my plan to go with 45rpm spider if I go that far. No, the pole was not left-handed as I unscrewed ...morzh — 07:14 PM
Philco 40-120C Restoration
Change the tube. Check the tube's bias network. Are any other tubes experience the drop or just this?` Is resistor 23 OK...morzh — 07:09 PM

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

>