[Hallicrafters] SX-117 VFO Problems

[kiyoinc at attglobal.net]

<richard.arland at verizon.net> Wrote:

I have a weird problem on an SX-117.

>The VFO drops out after about 150 kc of tuning range. I noticed this when I was attempting to align the receiver by going from the top to the bottom of the tuning range. 
>
>Any suggestions? 
>  
>

I had a similar problem with an SB-303.  It tuned OK at one end of the 
range, got wobbly in the middle and dropped out completely at the other end.

Turned out that the metal contract spring on the capacitor was dirty and 
not making a good electrical contact past a certain point.

I used de-ox-id on the contact spring and stuck a piece of cardstock 
between the spring and the rotor shaft.  Stroking the cardstock and 
turning the capacitor.   I did this until the card stock came out clean.

This fixed the Heath.  I took voltage measurements on the LMO output and 
the signal was much stronger and the waveform was cleaner and steadier 
after the cleaning.

It is a BEAR to get into the Heath LMO, it's like a half day job as you 
have to pull the front panel to get the LMO subchassis out.

de ah6gi/4