[Collins] wanted 75s-3b parts

[Dr. Gerald N. Johnson]

Some of the sources mentioned at:
http://www.collinsradio.org/directory/DisplayCategory.aspx?cid=1 appear to
have knobs, and maybe other parts.

The fuse holder I believe is a stock
Bussman part, probably HKP according to my printed S-3B manual. The 
latest manual calls it an HKP1. I think the standard HKP as in part 
number 504-HKP from Mouser with over 4K in stock for $2.40 will be a 
perfect fit. Its not a special and is still made. If you have any 
remains I think they will show that HKP Bussman part number.

I have an empty case but I don't know what size it is or where it is at 
the moment, at least not closer than within a 100 boxes that have the 
basement stacked full.

The band switch shaft seems to be a problem. Used to be we could buy 
switch index assemblies with long shafts, at least surplus. Its 
basically a double flatted quarter inch diameter shaft. I measure the 
flats as being 3/16" inch apart to the nearest .001" on a switch in my 
switch box. Most everybody used the same shaft dimensions. But the usual 
sources I checked today don't admit ever hearing of such an item or 
their computer search engines are faulty. It would not be a difficult 
machining task with a vertical or horizontal milling machine and a piece 
of 1/4" aluminum or steel rod. Aluminum would machine easier and not 
rust, though I think the original was steel and plated after machining. 
I can't tell from my manuals whether it was made or purchased. It could 
have been supplied either way and probably over the production life of 
the S-line (also used in the 32S) it was both made at Collins and 
purchased. It could also be turned in a metal lathe staring out with 
3/16 x 1/4" stock and turning the 1/4" dimension round. I think it would 
mill easier than turning that long length which will tend to bow away 
from the cutting tool while the entire length can be supported on the 
milling table.

That shaft is not a tough duty job, so one might make a temporary shaft 
sanding, filing, carving, routing, or sawing on a hardwood dowel, though 
a bit of 1/4" dowel I picked up last week didn't make it home in one 
piece it was so poor quality.

The other parts will have to be found from places disassembling S-line 
or KWM-2 gear. There are several sizes of cases, but knobs, are all the 
same, escutcheons only differ by the engraving as far as I know. I 
suppose one could fill the S-1 engraving on the escutcheon at Surplus 
Sales of Nebraska and get it reengraved S-3B.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.


On 8/6/2011 3:35 AM, L Ritta wrote:
> Hello All
>
> I am trying to restore a Collins 75S-3B receiver and need some spares
>
> Main knob (vfo)
> band switch shaft
> knobs for preselector, af/rf gain, mode, power
> clip for the metal band used in the slug rack
> 75S-3B black plastic escutcheon
> fuse holder
> Case
>
> If you can help please holar.
>
> 73, Lee.
>
>