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POT clean OR repair?
#1
Photo 

Hey Folks.  I have 53-1750 Radio/phonograph, which I restored a couple of years ago.  It has been running like new but all of a sudden it developed on a LOUD high pitch squeal when the volume is turned up.  I traced the problem to the volume/tone control POT.   I sprayed it with CRC contact cleaner and the problem is 95% better. However, if I flick it with my finger, I get a popping sound.  So my questions:
1.  Is there any advantage to taking the POT apart and cleaning it out or am I going to just F--K it up by doing that?
2.  They do make contact cleaner with lubricant - is that better than just using the contact cleaner?
3.  Have any of your ever re-built one of the volume POTS - ?

Thanks


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#2

We always try cleaning before taking it apart. Try Deoxit D5 spray then work the control many times. Usually it is more difficult to un-solder the control than to take it apart To remove the front and shaft there are several tabs around the outside. Slowly pull the tabs straight with a long nose pliers. The shaft and front should pull off easily. Most of the time a good cleaning with alcohol and a soft brush will do the trick. Sometimes the resistive element will have a groove worn in it or a hairline break at one end, in which case find a replacement. GL

Rod
#3

Or it has been cleaned with the wrong cleaner.

"I just might turn into smoke, but I feel fine"
http://www.russoldradios.com/
#4

Yes. Deoxit. F5. NOT D5!!!!!!!!!!!!, Green label, Fader Lube.
D5 is the contact cleaner, will kill some pots.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#5

<Deoxit. F5> Why doesn't someone tell me these things?
#6

Yes, not D5. I've been experimenting with something else and if the results remain positive, I'll report. It does require disassembly, though.
#7

Rod,

D5 is a contact cleaner, thereby aggressive and potentially damaging for potentiometers.
F5 is a Fader Lube, specifically formulated to lube resistive elements of potentiometers.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#8

If you ever come across a TrolMaster (i was lucky to stumble upon one on eBay), you might not need disassembly for many pots.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#9

If you have an ultrasonic cleaner, get some Miicro-90. I was able to rejuvenate an one-off switch and pot combination from dark, heavy tarnish to bright brass and copper, making the part fully functional.

Otherwise, deoxit or 5% oleic acid in solvent should restore it.
#10

A few months ago I sent for what I thought was Deoxit F5. After seeing this discussion I went and looked at what I received and turns out it is Deoxit Fader F100! It says it cleans and lubricates pots but I haven’t used it yet. Just wondering is there a difference between F5 and F100?

Ron

Bendix 0626.      RCA 8BX5.   RCA T64
Philco 41-250.    Philco49-500
GE 201.             Philco 39-25
Motorola 61X13. Philco 46-42        Crosley 52TQ
Philco 37-116.    Philco 70
AK 35                Philco 46-350
Philco 620B.       Zenith Transoceanic B-600
Philco 60B.         Majestic 50
Philco 52-944.    AK 84
#11

Ron, the buffet of products that Deoxit offers can become confusing.  F5 is Faderlube with a solvent to clean and a 5% solution of lubrication.  F100 is 100% lubrication with no cleaning properties.  So I use D5 for switch contacts, F5 for potentiometers and maybe add a drop or two of F100 (mine is in a needle dispenser) to keep them smooth.

Mike's TrolMaster might be found on eBay or a lucky garage sale find and later versions were called a goesinta,  Below is a link to all the details:

https://philcoradio.com/phorum/showthread.php?tid=19667

Mark Oppat sells a cleaner only and a cleaner with lube that I'm sure is cheaper than Deoxit. I do google searches for the best Deoxit price and usually find them at guitar/music shops online for the best price.

John KK4ZLF
Lexington, KY
"illegitimis non carborundum"
#12

If buying Deoxit by a traditional spray can, do not buy the one with the swivel, those leak alot.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#13

Hi Elliot, I swore I ordered F5, never looked at it when it came a few months ago, but looked now and it’s F100 so, I’m thinking I could use a sprits of CRC followed by F100! I actually do have a ‘Trol Master’. My dad did TV/radio repair in the late 50s and I still have most of his stuff. If you look at that thread you posted above, you will see the discussion and picture of my Trolmaster. I don’t remember what I paid for the F100 from Amazon but I know it was expensive for a tiny can!

Ron

Bendix 0626.      RCA 8BX5.   RCA T64
Philco 41-250.    Philco49-500
GE 201.             Philco 39-25
Motorola 61X13. Philco 46-42        Crosley 52TQ
Philco 37-116.    Philco 70
AK 35                Philco 46-350
Philco 620B.       Zenith Transoceanic B-600
Philco 60B.         Majestic 50
Philco 52-944.    AK 84
#14

CRC followed by your F100 sounds like a plan. That's pretty cool you have a Trolmaster, and even better that it belonged to your dad!

I think the main concern with cleaners other than Faderlube is some have reportedly dissolved the carbon tract of the pot being cleaned, but that obviously wouldn't be an issue with a wire-wound pot and a spritz of F100 after should keep it smooth.

John KK4ZLF
Lexington, KY
"illegitimis non carborundum"
#15

I usually get to wash pots, no dishwasher............they squeak when clean!Icon_smile

Paul

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