Sean what you have to realize, is that retuning a radio is a simple
operation. Let alone does it give you the best possible signal, but it
protects your equipment and valves. Those valves are not going to get any
easier to find over the years, hence forth, their price will continue to
rise. If you are kind to your radio, it is possible to get twenty years out
of a set of finals. That means tune your finals, and make sure the radio
sees a flat SWR. The audio oscellator is more accureate than the meter.
Backk off the drive until you get comfortable with the process. 10 watts
will be plenty for adjustment power. I ran a set of 6JB6 sweep tubes for 25
years on that system. Those are no near as rugged as the 6146 tubes that
the kenwoods used.