It is highly advisable to re-adjust amplifier tuning when antennas have been changed.
Update tuning periodically, even if you have not changed band or antenna, in particular when a significant
change in the environment occurs (snow, ice, newly appeared or removed massive objects, alien wires
nearby etc.) that would cause significant changes in the antenna impedance.
If you use more than one antenna per band, it is necessary that you select the proper
antenna BEFORE to perform the tuning procedure outlined below.
NOTICE
Do not switch the BAND switch knob while transmitting with the amplifier! Hot
switching (while transmitting) will eventually destroy the band switch, not covered by
the warranty!
NOTICE
When tuning, never apply continuous drive longer than one minute without pausing for
at least one minute to allow the tube to cool.
It is recommended that for initial tuning a free frequency in the middle of the band be selected (make sure
the frequency is not being used by others so that you do not make QRM). First, with no transceiver power
applied, select the band. Then use Table 4-1 Approximate tuning preset in order to achieve an approximate
preset for both TUNE and LOAD capacitor knob settings:
Table 4-1 Approximate tuning preset