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 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:
[-]
Recent Posts
1949 Motorola 5A9M
hello mr Fixr, for sure !! I have some radios that I need to make some batteries for too. Sincerely richardradiorich — 12:33 AM
1949 Motorola 5A9M
Dittos, sweet b on the battery. Love the "9 Lives" logo, remembered from my childhood. Other neat ones are t...MrFixr55 — 11:24 PM
Philco 46-1209 strange behavior
Hi Morzh, Dunno if the AC EMI caps are an issue. I never liked the concept but never had an issue with these causin...MrFixr55 — 11:21 PM
Philco 46-1209 strange behavior
And no hum without the 7AF7? Not common but I am thinking heater - cathode short. This would introduce hum in this sta...MrFixr55 — 11:14 PM
schematics
Those filter caps in the cardboard tube are easy to restuff, especially the kind with the rolled over end. You don't hav...Arran — 09:56 PM
Philco Model 16 wiring question
If you have 5 wires, do this: The wires that go to thick-wire wound winding are the filament. If you do not know wha...morzh — 09:03 PM
Philco Model 16 wiring question
I recently acquired a Philco Model 16 Code 126. I removed the power transformer to place heat shrink on some very bad...bobclausen — 08:23 PM
1949 Motorola 5A9M
Hello Bob, That battery looks great nice job ! Sincerely Richardradiorich — 08:20 PM
1949 Motorola 5A9M
Yes, I plan to put a Velcro closer on the top.klondike98 — 07:28 PM
1949 Motorola 5A9M
Nice job on the battery, Bob. Can the box be opened to replace the 9 volters?RodB — 11:32 AM

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

>