Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

Philco Model 20 volume control operation
#1

I cant seem to get an answer on this on another forum. Thought i would ask the Philco experts.

I just finished a recap and resistor replacement. The radio plays well except that the volume is loud even on the low setting. It does get a bit louder as you change the knob setting clockwise as it should though.

I dont really want to use it since I can't adjust it down to a comfortable level. Is this normal for this set? (That is what I would really like to know.)

I do have a spare console chassis that I can scavenge and switch volume controls if needed, I just dont want to waste time if this normal. The one I have in there now looks original.

Did this set have a dial lamp? Mine doesn't, but my spare chassis does.
I thought of replacing it with that one.

Thanks for the advice.
#2

On that set the volume control pads down the antenna rather than the audio amplifier. Make sure your volume pot is grounded on the bottom lug. The other thing to do is use a shorter antenna. With a good antenna and a strong station you can get lots of audio with the antenna attenuator (volume control) all the way down.

keithw
#3

Steve

the pot is dual, one half divides the antenna signal while another adjusts cathode potentials.
1. measure the values of both sections, make sure they are OK.
2. Make sure the soldering is correct, especially that GND point as Keith just said.
#4

The volume control should be a dual pot. One section, as Keith described pads down the antenna input and decreases the signal level. The second section adjusts the bias on the RF amplifier tubes and sets the level of signal amplification.

It sounds as if the second pot section on your radio is not working properly. This pot is connected as a voltage divider, connected as part of the large wirewound resistor on the side of the chassis. If you connect a voltmeter to the sliding contact of this pot section, you should see the voltage change by several volts as the pot is rotated. If you see no change, then either the pot is bad or there is an open section in the wirewound bias resistor.

If working properly you should have good control of volume level, even on a fairly strong signal.
#5

Thanks. I will have some time this weekend to check what each of you has said.
#6

Hello SteveJB, later production of these 20's had dial lamps. Yours must be an earlier set. The lamp is easy to add to the dial, and it taps the tube filament wiring for power. Take care, Gary.

"Don't pity the dead, pity the living, above all, those living without love."
Professor Albus Dumbledore
Gary - Westland Michigan




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM
54C Complete Teardown/Rebuild
Hello roy, here is a link to the schematic . Sincerely Richardradiorich — 11:54 PM
54C Complete Teardown/Rebuild
Richard, The Silvertone 2014 also is a transformerless set, so I am incorporating a 1:1 600 ohm audio isolation transfo...glyphmon — 11:37 PM
Preliminary work on wife's Silvertone 2014
Did an alignment today which was interesting.  IF alignment went great, almost all was already spot-on.  Adjusting on th...glyphmon — 11:35 PM
54C Complete Teardown/Rebuild
The main problem with adding a Bluetooth input is that this set lacks a traditional power transformer to isolate it from...radiorich — 11:19 PM
54C Cabinet Refinish
I started stripping this cabinet before it got super chilly out because I knew I wasn't going to be able to work on ...glyphmon — 11:18 PM
54C Complete Teardown/Rebuild
While I'm waiting to wrap up the final steps on my wife's Silvertone 2014, I started disassembly on the next project.  O...glyphmon — 11:07 PM
Preliminary work on wife's Silvertone 2014
Hello roy, that great news glad it worked out for you !! Sincerely Richardradiorich — 10:50 PM
Preliminary work on wife's Silvertone 2014
Safety caps arrived today.  Soldered one in and had a successful first power-up.  No magic smoke escaped and it tunes in...glyphmon — 09:53 PM

[-]
Who's Online
There are currently 1418 online users. [Complete List]
» 1 Member(s) | 1417 Guest(s)
Avatar

>