[Heathkit] SB-200 10M Power Output

[Mark K3MSB]

Folks --

I'm working on a friend's SB-200.

I'm getting between 550 and 600W out (CW) on 80-20,  500W on 15,  and
between 300 and 400 on 10M.

I'm trying to figure out if there's anything I can do to increase the
output power on 10M.  Here's what I've measured:

28.0:   350-400W.   (75W drive, 1.5:1)
28.4:   300W          (75W drive, 1.5:1)
29.0:   300W          (50W drive, 2.1:1 )

For reference:

14.2:  600W  (60W, 1.2:1)

The figures in parenthesis are the drive from my 756P3 and the SWR
indication between 756 and linear.

I initially thought to adjust L1 to bring down the SWR for a better
tuned input match for the phone band.  However, after looking at what
I'm getting on the low end of 10 (good SWR) and the mid and higher
parts of 10M (mediorce SWR),  I don't think it's worth it to muck with
L1 to get another 50 to 100W of output power.    I'm getting plenty of
drive as it is.

The tubes are not new, and I've had to replace just about every
resistor in the beastie.   I'm thinking the tubes are just soft.

Comments?

73 Mark K3MSB