[Hammarlund] HQ-129 and 717A mod and SP-600

[Kenneth G. Gordon]

On 7 Nov 2007 at 15:09, Todd, KA1KAQ wrote:

> Ah, yes...the famous 'Nuvistor Plug' mod. Would love to find one, or
> at least see the documentation. Heard wonderous things about this over
> the years...

Hee hee! Here you go!

<http://www.mines.uidaho.edu/~glowbugs/SP600upgrd.pdf>

I see it was originally printed in a military technial manual...

Ken W7EKB