[Hammarlund] SP-600 update

[James A. (Andy) Moorer]

Funy - I've replaced that exact, same one in several different receivers. I 
wonder if they tried to save a few cents on that one.

The symptom I noticed is that I couldn't get a peak when tuning L31 - it 
went all the way to the stop without a peak. Its companion (L32) peaked just 
fine.

BTW - that one is a &%$#!@ bear to get to in the JX series - you have to 
take the FCU and the power supply out. Real pain.

James A. (Andy) Moorer
www.jamminpower.com

----- Original Message ----- 

> For you SP-600 owners, you mite want to pursue this part replacement. 
> After
> hours and hours of troubleshooting and checking and rechecking components, 
> I
> come to the conclusion that the turret assembly had to come back out. 
> Reason
> is I had to get at L-31. There is a capacitor ( C-67 ) across this
> capacitor. The value of mine is 85 mmf. I pulled the unit apart and 
> unsolder
> the cap. I then put the cap on my trusty Heath cap checker and carefully
> watched the eye tube. It would flutter just a bit as if it wanted to close
> up then reopen. It wasn't much of a flutter. I didn't want to take any
> chances of having to remove the turret assembly again so I replaced the 
> cap
> with an 82 mmf, silver mica that tested good on the Heath tester. After
> reassembly and readjustment of L-31, 20 meter cw and the phone band was
> coming in like gangbusters. I am able to tune the 17 meter band.
> A word to the wise. DON'T trust those old micas. If there going to be hard
> to replace in the future, do it now, get it over with. Although the lower
> bands seamed to function great, this cap ( C-67 ), being a bit leaky, was
> affecting the performance of the receiver. It seamed that the higher the
> frequency tuned, the less selective and sensitive it got.