Posts: 19
Threads: 5
Joined: Mar 2017
City: Cashmere WA
I have a resistance of 30 to 70 ohms or so across the on/off switch contacts on the back of the volume potentiometer. It varies as I wiggle the probes of the DMM. I've tried contact cleaner and exercising the switch, but I need to get in there and polish the contacts.
Some of my repair parts literature mentions replacing the volume pot with "manufacturer part # xxx and adding the on/off switch contacts to the back of the pot".
Looking at my volume/on/off control, it looks like the switch on the back would come off, if I knew the trick of getting it to release.
Can anyone offer any guidance? Is there another method of cleaning these contacts?
Thanks in advance,
Dan
Posts: 184
Threads: 3
Joined: Feb 2018
City: Chesapeake VA
The guy who coined the term "a picture is worth a 1000 words" was a smart guy...
There are different configurations depending on mfgr/style/model of switch...
Posts: 1,231
Threads: 29
Joined: Jan 2014
City: Wellborn Florida
Try using WD-40, lots of WD-40 take your time. David
Posts: 19
Threads: 5
Joined: Mar 2017
City: Cashmere WA
Good point. I'll talk to my in-house tech support (teenage daughter) and see about getting a pic or two posted here this afternoon.
Posts: 16,230
Threads: 563
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
30-70 ohms is an ok resistance. The radio has not been used and it has oxidized. Once energized the current will clean it up. If it were megaohm then yes, needs cleaning. I usually don't bother with tens of ohms.
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.
Posts: 19
Threads: 5
Joined: Mar 2017
City: Cashmere WA
I finally bit the bullet and teased the whole switch and pot apart, since there was an odd 'bump' in the rotary travel of the pot, about 1/3 the way through. Felt like a detent in the motion of the switch.
The center solder lug was loose, gently crimped it back down and all was well.
I took a picture with my phone, but due to technical difficulties I was unable to get it off the phone. Software issue, according to the PC. Probably because it's an old, dumb flip phone. Probably hasn't been supported since George W was President! Even my daughter couldn't get it to work... so I don't feel bad.
No shortcuts with this anyway, had to bend back another set of tabs to get the switch off the back of the pot.
Got it back together, it doesn't look like it was ever apart. Resistance reads are good.
Thank you all for the advice! This little project is getting to be a head banger.
Dan
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
