[Boatanchors] Lysco 600S Loading

[Vic Rosenthal]

Bill Stewart wrote:

> With the Lysco working, I was anxious to get it paired up with a HQ-129X and
> get to pounding some brass. However, since the output is single ended and has
> no antenna loading cap., I couldn't get the final to load high enough to get
> much output. Into a cantenna I get anywhere from 60ma to 75ma (at the dip) on
> 1.8, 3.5 & 7 mc. It made it up to around 100ma at 28mc. When I connect my
> 80/40 mtr inv. vee I get even less plate current and the output power is 5
> watts or less. I did hang a 900uuF var. cap across the output to gnd, but
> really didn't t seem to help. The spec sheet says the PA should be around
> 125ma. What do I need to do to get it to load and give more output. 

Looking at the schematic, it appears that the output circuit is just a parallel 
tuned tank with a tap up from the bottom of the coil.  Some models seem to have 
a LP filter between the tap and the output.

Are you getting the correct amount of grid current?  If so, and if the plate 
current dip is very deep, then maybe the coil tap is not set correctly.  Could 
you (or a previous owner) have changed any of them?  Insufficient loading could 
mean that the tap needs to be moved up (away from ground) on the coil.  Another 
possibility could be a bad capacitor (open or changed value) in the LP filter. 
You might try disconnecting the filter and taking the output directly from the 
coil tap to test this.

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco