[Boatanchors] Heathkit SB-200 Question - Seeking advice

[Glenn Little WB4UIV]

I would suggest using penetrating oil rather than Water Displacement 
40, unless you have water to displace.
Water Displacement 40 will remove any lubricant that is still there 
and leave you with gum.
The penetrating oil will very thin oil to the area without significant gumming.
If you can get it free, I would remove any rough spots and lubricate 
with thin oil such as rose oil.

73
Glenn
WB4UIV


At 09:49 PM 4/8/2011, whitebear1122 at comcast.net wrote:
>I just acquired a nice SB-200, looks nearly new. The frequency knob 
>doesn't turn. It doesn't budge. When I couldn't get the knob off I 
>figured I was at the verge of a new adventure in restoration.. I 
>eventually got the knob off but I had to wale on it. Oddly the knob 
>insert stayed on the shaft.. Geez.... I got the insert off with the 
>pliers. Don't know what the deal is with that.
>
>The detent mechanism grease looked minimal and old I though perhaps 
>it was stuck on old grease so I sprayed it with WD-40 and let it set 
>for a while. Still wouldn't move so I removed the whole rotary 
>switch assembly. It was easy enough to remove. I did have to 
>unsolder some of the wires on the outside wafer so it would move out 
>of the way and allow the shaft to back up enough to lift the whole assy out.
>
>I then disassembled the rotary switch assembly and removed the 
>detent and shaft from the wafers. The shaft still doesn't turn. I 
>put the edge of the detent mechanism into the vice and used some 
>pliers to work the shaft back and forth. Nothing. It doesn't turn 
>like it should, but the bushing moved along with the shaft. Geez.... 
>I'm guessing the shaft is corroded into the bushing.
>
>About all I can think of is to saturate it with WD-40 with the 
>bushing facing down, hopefully getting the WD-40 inbetween the 
>bushing and shaft, then put it a baggie to minimize evaporation, and 
>let it sit overnight.
>
>As I think about it, I suppose I could try to heat up the bushing 
>assembly and see if there can be some expansion to pull away from the shaft.
>
>I have never encountered this difficulty before. What a pain. Well, 
>I am able to get further into the amp and clean out the dust.. hi hi
>
>Since I've got you on the line, one of the 572's has a loose cap. 
>What is the glue of choice to secure the cap to the glass envelope?
>
>Any suggestions are appreciated. Thanks. 73, Scott WA9WFA
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