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

Help with the volume control - model 70
#1

I recently had to replace the dual control on my model 70 with a single control and am experiencing a strange problem.

Starting from fully off, the volume increases as I turn the knob clockwise but, at a fairly low level, the volume decreases and completely disappears as I continue turning the knob clockwise!

I don't have a scanner to show the circuit which came with the replacement kit which I purchased but I replaced the 225 ohm section of the original dual control with a 220 ohm fixed resistor and, to quote the instructions a 270 ohm resistor is added to "supply initial bias on RF and 1st IF grids".

This problem wasn't present before the change and wonder if anyone on the forum might have an idea as to what is causing this problem.

My apologies for such a long question for my first posting!

Thank you for your help.

Joseph


Messages In This Thread
Help with the volume control - model 70 - by doverite - 07-21-2013, 10:32 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 46-480 Electronic Restoration
Late last night a guy reached out in response to my posting on the Antique Radio Forum and suggested I contact Trust Aut...jrblasde — 11:01 AM
Philco 630csx power cord
Have you opened up that plug? It may be that the third wire is connected to that brass stud on the side of the plug and ...Arran — 02:57 AM
Model 27-84 BUZZ?Humm?
I would have to look at the schematic but it's not uncommon in 1930s AC radios to have the negative of one filter cap co...Arran — 02:46 AM
Model 27-84 BUZZ?Humm?
Hello Bruce, First all do mean a 37-84b ? Did you take any before and after pictures ? is it a buzz like when you touch...radiorich — 01:59 AM
B&K 1077B no video - problem solved
Hello Tim, Yes, I even check all of my replacement parts when I install them and I too had a capacitor go bad not long a...radiorich — 01:54 AM
B&K 1077B no video
I got back into it tonight. Problem found and resolved! Sometimes it helps to take a break and think things over. It was...TV MAN — 12:40 AM
6TPZ and 5TPO Radio Help
Thank you. I have to take a break from it for about a week. I'll have to do some thinking. I was toying with the idea ...R3Sons — 12:21 AM
Model 27-84 BUZZ?Humm?
Drowning in a overloud buzz/Humm. Have already changed filter caps,bakelite blocks( caps),out of speck resistors,checked...Bruce — 12:17 AM
Philco 630csx power cord
Hello Mike Here is the Link to the company the place is called Grand Brass lamp parts . I buy all my Lamp parts plus ...radiorich — 12:00 AM
Philco 40-120C Filament Wiring
Is the tube in your radio actually 35Z3 or 35Y4, or something else?morzh — 10:55 PM

[-]
Who's Online
There are currently 2604 online users. [Complete List]
» 3 Member(s) | 2601 Guest(s)
AvatarAvatarAvatar

>