Remember, original poster is asking about a Heathkit SB-200 amplifier. The amplifier was designed in stock form for a 75 to 100 watt SSB drive. The meter Grid position only refers to a range on the meter and not actual values. If you're going to dip and load, using a 100 watt or less exciter, all you really need is the plate meter. There is no neutralizing adjustment on this amplifier. Unless the building process was really screwed up, it's a linear amplifier, and with a few watts exciter applied in the AM or CW position, adjustment for maximum forward power output works fine. No peckers or diddlers or ah'sssss into the mike are needed.
Pete, wa2cwa
Sure, apply 5-20 watts of cxr, then tweak tune + load for max PO. BUT, it's still not tuned up for 500-700 w pep out. If u just tune up initially with low drive, THEN increase the drive level, u will get a miss tune every time. The load control will still have to be advanced a lot more. When u increase the loading control, you are DE-creasing the load C. AS the numbers on the load control increase, the actual pf of the load cap decreases. IF you use a cxr, with low power initially, fine, but u will have to keep tweaking the drive level higher ( with a cxr)..and keep increasing the load C at each step.
So u end up tuning the amp from low to max power...with an ever increasing CXR. Just easier to use a pecker, with a 20-50% duty cycle..and a pep wattmeter. The low duty cycle pecker takes a huge load off the tubes, bandswitch, tank coils, tuned input networks, both band switches, and the plate xfmr. Then perhaps hit it with a 80-100w cxr, then take a quick plate + grid current meter reading.
The grid and plate current meters are only accurate if a cxr is used. They are both semi average reading devices.