[Boatanchors] FS: Heathkit SB-303 Receiver

[Mark Johnson]

Hi Greg,

There are many who advise that a satisfactory fix is to clean the LMO
variable cap with some kind of contact cleaner and then re-apply some kind
of conductive grease. I've never tried the conductive grease. My fix is a
bit more difficult to apply but it's permanent.

I solder a small flexible braid directly to the rotor shaft of the variable
cap and then solder the other end directly to the variable cap frame. A good
sized 100W soldering iron will work fine and the frames and rotor shafts
take solder nicely as long as you file a good sized clean spot on the area
you want to solder to.

I use a small piece of copper braid material. You need to have just enough
length so that as the cap turns, it will wind around the shaft and not
interfere with the variable cap or the related electronics inside the LMO.

The LMO's on the SB-303 and SB-313's are the toughest as there is not a lot
of room in there and you need to disassemble a lot of the LMO to get at the
variable cap rotor shaft. It takes patience and care but I've done several.
With care, you won't upset the linearity of the LMO.

The tube LMO's from the SB-300's, 400's, 101's, 100's, 301's etc. are the
easiest.

Once done this way, you'll NEVER have a "wobbly" or scratchy LMO again.

Mark VE3LU/VE3DJU

----- Original Message ----- 
From: "Greg Carter KX4R" <kx4r at earthlink.net>
To: "Mark Johnson" <mvjohn at sympatico.ca>
Sent: Saturday, December 04, 2010 6:32 PM
Subject: Re: [Boatanchors] FS: Heathkit SB-303 Receiver


> Hi Mark !
> I have an SB-303 with the wobbly vfo problem you mentioned....would you be 
> able to share your fix with me ?????
>
> Tnx and 73, Greg  KX4R
> http://home.earthlink.net/~kx4r/
>
>
> ----- Original Message ----- 
> From: "Mark Johnson" <mvjohn at sympatico.ca>
> To: "Boatanchor List" <Boatanchors at mailman.qth.net>
> Sent: Saturday, December 04, 2010 3:12 PM
> Subject: [Boatanchors] FS: Heathkit SB-303 Receiver
>
>
>> Team,
>>
>> FS, Heathkit SB-303 receiver. Front panel, knobs, feet, dial; all in very 
>> nice condition. Cabinet is good with original paint that is showing some 
>> age.
>>
>> I repaired a "wobbly" LMO problem, and the calibrator, and did a full 
>> alignment. Receiver works great!
>>
>> Has optional CW filter and comes with manual. $200 plus shipping and 
>> insurance.
>>
>> Mark V Johnson
>> VE3LU/VE3DJU
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>