Replacement for "O" rings.

[Stu Lyon]

I think the O-rings were used on the Driver tuning to solve a syncing 
problem since none of the four driver pulleys had set screws but were 
instead fixed to their shaft. The use of the O-ring on the Load 
capacitor was just a bad mistake. The O-ring specified is too short 
which causes high side loads on the loading capacitor. The next size up 
slips and feels mushy.

The SB-400/1 always used dial cord on the load cap and the SB-102 
returned to that scheme. It works well on both of them.

The dial  springs can be purchased at Lowe's and OSH (they have the same 
display). Pick the smallest spring in the display which I think is 1/8 
dia x 1.5 long. Dial cord can be some types of fishing line, dental 
floss (scent optional) and on eBay. You don't want the type w/  a 
"fibra-glass core".

73, Stu W6CUX

Walt Van Arsdale wrote:

>When Heathkit first produced the SB-series, their methodology for connecting
>these pulleys was the "old" method of using dial cord and springs.  They
>continued to use the same pulleys but switched to the O-rings.  I built one
>of the first SB-100's with the dial cords and it lasted for about 10 years
>until I sold it.  I never knew why the switch was done...  perhaps the rings
>were cheaper, or maybe customers were having trouble with the task. ???
>73
>
>Walt  K5SXO
>
>I just today found a one-page copy of the procedure for substituting a
>sprung bit of dial cord for those stupid "O" rings in the HW/SB
>transceivers.
>
>It is somewhat confusing, but I will clear that up, scan it, make a PDF
>out of it and send it to anyone who wants it.
>
>Although I am not sure where I got it, it looks very much like something
>that the Heath company put out as a service bulletin sometime in the
>past.
>
>This will eliminate the problem with them being destroyed by whatever
>is in the air in my shop at work...
>
>Ken W7EKB
>
>  
>

-----------------------------------------------------------
Products bought, sold or traded here is the responsibility of the
parties involved.  This list and the City of Tempe are not responsible
for losses or misrepresentations of any kind.  Buyer beware!

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.asp?list=HEATH
To post - HEATH at LISTSERV.TEMPE.GOV
Archives - http://listserv.tempe.gov/archives/HEATH.html