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 42-1013
#1

Have this thing re-capped now and it does play.
I don,t seem to have the volume I would like,and if you turn it up to about 1/2 volume it starts getting distorted and the volume does not really go up.
Someone replaced the volume switch with a combe on/off/volume switch due to a bad switch on the off pushbutton.
I wonder if the switch is under-rated for that chassis,or if there could be something else I should be looking at like maybe a tube?
This one has been a bear for a newbie like me to work on.
Any idea's?
Thanks again,
murf
#2

You picked a difficult set to start out. As far as distortion, I would make basic voltage checks in the audio section with emphasis on the audio output bias. Should be about -20V on the control grids of the 7C5s. Also make voltage readings on the other tubes in the radio too. Often problems can be found this way without elaborate test equipment. If basic voltage checks are good then alignment will have to be considered.

Concerns about a under-rated switch is misplaced. Tubes are usually Ok. These being locktal tubes there is concerned about pin connection issues. Rocking the tubes in the sockets can reveal a intermittent pin while listening to the radio.

http://www.nostalgiaair.org/Resources/497/M0013497.htm
#3

rghines1 Wrote:You picked a difficult set to start out. As far as distortion, I would make basic voltage checks in the audio section with emphasis on the audio output bias. Should be about -20V on the control grids of the 7C5s. Also make voltage readings on the other tubes in the radio too. Often problems can be found this way without elaborate test equipment. If basic voltage checks are good then alignment will have to be considered.

Concerns about a under-rated switch is misplaced. Tubes are usually Ok. These being locktal tubes there is concerned about pin connection issues. Rocking the tubes in the sockets can reveal a intermittent pin while listening to the radio.

http://www.nostalgiaair.org/Resources/497/M0013497.htm


Voltages were checked as well as audio output.All seem fine.
Have had tubes out for cleaning and testing.
Is there a way to check the volume switch that was replaced?
Thanks for the help.
murf
#4

Little hard to read the schematic. Thinks it reads 2 Meg total with a 1 Meg tap. Believe the tap is for improving bass at low volume. Beginning to think the volume control replacement was poorly executed. Verify resistance and presence of a tap on the replacement and associated wiring. Not unusual to see poorly done vintage repairs for parts shortages, etc. Might find a replacement if needed from Mark Oppat at oldradioparts.net.
#5

rghines1 Wrote:Little hard to read the schematic. Thinks it reads 2 Meg total with a 1 Meg tap. Believe the tap is for improving bass at low volume. Beginning to think the volume control replacement was poorly executed. Verify resistance and presence of a tap on the replacement and associated wiring. Not unusual to see poorly done vintage repairs for parts shortages, etc. Might find a replacement if needed from Mark Oppat at oldradioparts.net.


Will check it out when I can.
Thanks again




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
The list of my radio & TV collection!
EdHolland. Glad you liked it. Thanks for the supportRadioSvit — 05:24 PM
The list of my radio & TV collection!
Great stuff, Peter thank you for posting.EdHolland — 04:06 PM
My Philco 37-116 Restore
The crack goes from almost the bottom of the tube to well past the fat part. It is an ST type tube. The filament is open...dconant — 10:04 AM
My Philco 37-116 Restore
Where is the crack? A cracked tube that has air inside will turn opaque once turned on. Perhaps it is a scratch, nogt a...morzh — 09:50 AM
My Philco 37-116 Restore
I found I have a cracked 6J5 (AVC) tube. Since the tube shields are so tight I must have broke the tube putting the shie...dconant — 05:32 PM
My Philco 37-116 Restore
Looks like I made a mistake. I painted my tube shields silver. Now the reception is poor and can't really zero in on mos...dconant — 01:10 PM
Need Help to ID this radio 11 tube Philco
I did R73 RCA. It has a phenolic board with all stuff mounted on it. And the wiring is deep under everything including ...morzh — 10:37 AM
48-482 rear panel help
Hi Keith, here is an article that covers different FM detector circuits including a section on the theory and alignment ...462ron — 08:26 AM
462ron
Well then Dan I guess this old man’s memory wasn’t too foggy :lolno: although I couldn’t remember where I saw that upgra...462ron — 08:08 AM
Need Help to ID this radio 11 tube Philco
Fortunately, I did not have to do much to my GE S-22 (RCA R7A) Almost all caps and the 2 audio transformers packed into...MrFixr55 — 07:44 AM

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

>