[Hallicrafters] Hallicrafters Digest, Vol 82, Issue 25

[James Liles]

Good morning Richy:
The function switch is very seldom the problem.  The switch is mounted on a 
plate that is riveted to the chassis and has become loose and oxidized.  The 
early radios used screws.  I would stop any repair work now and do the 
following before you replace the function switch.

Drill one of the rivets out that hold the function switch plate and install 
a screw and star washer using Penetrox copper particulate compound (Copper 
butter --- like that used on the aluminum elements of an antenna) --- the 
zink compound is OK but I prefer copper.  Then do this ---- you are going to 
hate me for this one but the payback is immense.  Remove every screw in that 
radio and reset with a dab of Penetrox.  A handy device to administer the 
Penetrox is an 18 gage surgical syringe.  You say I can't afford that 
device ---- wrong, they cost $.26 at your local pharmacy and while your 
there buy a 28 gage version for Deoxit administration.  Now place a drop of 
Deoxit on every star washer that lives under a rivet and use a small hammer 
and narrow screwdriver to tap the star washer as you would try to turn a 
wheel to reset it.  VOILA you have just fixed %95 of the problems that will 
occur with the SR-2000, SR-400, and SR-400A etc.

Any radio that uses an aluminum chassis will have the same problems.  You 
can tell whether a radio has been stored in the garage where temperatures 
vary wildly or in the closet.  The garage kept radios always seem impossible 
to make work properly or are forever squirrely.  The SR-2000 is probably the 
most affected of all because it absolutely demands chassis continuity 
without unexpected chassis loops.  This is because of it's inherent power 
and collocation of components.  The above procedure is a permanent fix.

One of the most common complaints with the SR-2000 is "I can't neutralize 
that radio and if I could, it would be goofy tomorrow"  Again, the above 
procedure is a permanent fix.

BTW, L15 and L16 are best adjusted with a sweeper.  Don't understand the 
comment regarding the effect on the audio --- they have to be way off to 
affect audio quality.

Good luck and don't give up on that radio.  A Merry Christmas and Happy 
Holiday season to you and yours --- Kindest regards Jim K9AXN

> Message: 1
> Date: Mon, 22 Nov 2010 12:01:57 -0500
> From: ss409ss at aol.com
> Subject: [Hallicrafters] SR-2000 Audio
> To: Hallicrafters at mailman.qth.net
> Message-ID: <8CD587E1B405088-1F8C-280E9 at webmail-d073.sysops.aol.com>
> Content-Type: text/plain; charset="us-ascii"
>
>
>
>  Thanks Walt and Jim,
>
>   I had to remove the case to get at L-15 and L-16. The advancement of 
> those two controls yielded muddy audio from the speaker so I moved them 
> back and checked the test point with a freq counter. I also set the 
> carrier null while I was in there. I found that the function switch was a 
> big issue with this one, the radio emits a carrier in ssb, pulling 
> slightly on the switch and it goes away, also if the switch doesn't have 
> the same tension on it, the USB osc will drop out on occasion.
>
>  I am currently working on that function switch, I took many pictures then 
> I took it out and all apart, cleaned it, reset the wipers and contacts and 
> put it back in. I am head scratching on the wire placement for a few of 
> the connections but this was late last night so I went to bed and figured 
> I would get up with a clear head and finish it up looking at my pics, the 
> problem is the bottom wires that I couldn't get at with my camera. I did 
> mark all of them down on paper as I took it out but you know how that 
> goes..lol  Regards, Richy N2ZD