[Boatanchors] Re: [Hallicrafters] SX-42, Band 4 Progress

[Jim Wilhite]

If you have a modern solid state rig, just feed the signal generator into 
the input of the rig across whatever antenna impedance you will use.

If it is 50 ohms, use a Tee connector and put the signal gen. across one 
leg, a 50 ohm load (dummy load) across the other and the 3rd connector to 
the rig.

Vary the output of the gen from zero up to S 9 and make marks on your 
generator dial to indicate what you have.  Then move the antenna to the SX 
42 and use the dial marks you made to see what the receiver is doing.

Remember this thing will not be as sensitive on the upper frequencies 
(probably) as your modern rig, so make some allowances.  It should not be 
too far off though.  I have found that tuning for max sensitivity on any 
balanced input receiver is best accomplished with the expected antenna load 
in parallel with the signal generator.

73  Jim
W5JO




> Thanks, guys.
>
> 1. I did check antenna to ground (with the link closed). It read short on 
> each
> band. (By the way, I recently installed a knife switch on my long-wire 
> antenna
> lead in so I can easily disconnect the antenna when I'm done listening. 
> I've
> heard too many horror stories about lightning strikes or static build-ups 
> frying
> antenna coils).
>
> 2. I don't know how much I'm injecting. I'm using a Supreme signal 
> generator
> that is older than the hills but works well. When I get back to the SX-42, 
> I'll
> probably inject a signal into Band 3 and find the setting that is barely
> audible. I'll then inject a signal of that level into Band 4 and see what
> happens.
>
> 3. Band 4 was weak before the recapping of the RF section. I usually check 
> the
> receiver out on all bands before recapping so I can easily determine if
> something I did made matters worse. (Yes, I have been known to make 
> matters
> worse!).
>
>
> Joe Connor