[Amps] SB-200 Low output power on 80M

[Ian Hill - K8MM]

I have an SB-200 that putting out less than expect power on 80M. Tuning 
was done in accordance to Heathkit's instructions....basically for 
maximum smoke and reduce the drive a bit if the grid current goes over 
100mA. I expected the RF output power to be equal to or great than the 
power output on 40M and 20M, and then start falling off as you go higher 
in frequency. This has been my experience with other amplifiers with a 
pair of 572B tubes.

The tuned input SWR on 80M is 1.2 - 1.

Any thoughts what is going on?

Band         Plate V.         Plate Cur.         Grid Cur.        Output 
power         Drive power

80               1950               .460               .064            
       500                    100W

40               1950               .400               .094            
       675                     100W

20               1950               .400               .100            
       650                     100W

15               1950               .380               .100            
       550                     100W

10               1950               .460               .100            
       450                     100W


Thanks,
Ian - K8MM