[Heathkit] SB-610 Potentiometers

[Jim Shorney]

On Sun, 30 Oct 2005 10:53:16 -0500, carl lowry wrote:

>Picked up another SB-610 off eBay couple weeks ago from a Heathkit guy in California.
>ALL the Pots & Switches apparently have so much corrosion inside them that even 
>Contact Cleaner is not loosing them up. The particular ones are the Four  1 megohm, 
>One 100K ohm, and the One 7.5 Megohm Pots. I've looked on the Mouser Electronics
>Website for replacements.. but not real sure of what to order. What have you all ordered
>for replacements ?  Suggestions Please..  Thanks & 73s, Carl, k4zrd

I went through this with an SB620. The problem, in my case, was that
the shaft lubricant was hopelessly dried out and acted more like glue.

My solution was to carefully disassemble the pots completely by
removing the back cover and the C-clip that retains the shaft where it
enters the threaded portion. Soaking the shaft assembly in alchohol and
applying a little heat may help loosen things up, but I had to
(carefully) use vise grips and pliers on a couple of them. Once I got
everything apart, I cleaned all the old shaft lubricant out with
alchohol and re-lubed with Teflon grease from Radio Shack. It sounds
like a lot of work, but it was worth the trouble; the pots all feel
silky smooth now, and the Teflon shouldn't degrade over time like the
original grease did.

The nice thing about these parts in older gear is that you actually
*can* disassemble them in a pinch. Sometimes newer parts aren't so
cooperative.

-- 
Jim Shorney      -->.<--Put complaints in this box
jshorney (at) inebraska.com
Ham Radio NU0C
Lincoln, NE, USA
EN10ps
http://incolor.inetnebr.com/jshorney/