[Collins] RE: Broken 10M coil core on 310B

[Dr. Gerald N. Johnson]

On Mon, 2008-09-08 at 08:08 -0400, Bob Spooner wrote:
> > What are the dimensions, threads, and color codes of that slug? I've
> > found to my sorrow, that using a metal hex wrench is nearly always
> > disastrous, splitting the hollow slug nearly every time. Plastic isn't
> > as strong and saves the slug most of the time.
> > 
> > Sounds like it should be painted red if the standard color code.
> > Interesting that in the 310B manual I downloaded, there is a note at the
> > end of the parts list among others that says "replace broken slug in
> > L105." That's the last multiplier 10m coil. Unfortunately the parts list
> > doesn't show any details on that coil and slug.
> > 
> > --
> > 73, Jerry, K0CQ, Technical Advisor to the CRA
> > All content copyright Dr. Gerald N. Johnson, electrical engineer
> > 
> Jerry,
> 
> The slug is 1/4" in diameter and 1" long with a 3/4" #4 threaded rod on the
> end which has a screwdriver slot for adjustment from above the chassis.
> There is no color code, just the natural powdered iron grey color. The one
> that broke in my 310B is for L102, the second multiplier stage 10M position.
> 73, Bob AD3K
> 
I found two each with a longer 4-40 shaft. I checked them with a small
coil on my Q-meter. Their permeabilities are quite a bit different and
the high permeability slug lowers the coil Q at 14 MHz. The other
doesn't increase the inductance as much, but increases the coil Q.

If I had an address I could send both and you could return the one that
wasn't right and possibly make a contribution to my ham account.


-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer