[Hammarlund] HQ-129 and 717A mod.

[Kenneth G. Gordon]

I just did some reviewing of the 717A. Turns out that the 
713A is an identical tube with a bakelite base.

Also, the 717A/713A has a transconductance of around 
4000 micromohs, while the 6SS7 has a transconductance of 
less than 2000.

However, the 6SS7 is a remote-cutoff type and will work 
better with AGC, if you want to use that.

I know my old Elmer always took his RF amps off the AGC 
line and used manual control for them.

In any case, the much higher transconductance of the 717A 
WILL help with better sensitivity on 20 meters and above.

I wonder if there might be a tube with the same basing as 
the 6SS7 or 717A, which has even higher yet 
transconductance?

I'd be interested in trying it.

I might take a closer look at my BC-779s too...

Ken W7EKB