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2.4 WIRING
The exciter can be connected to the amplifier with any type of good quality 50-ohm coaxial cable.
Length and cable size is not important, except as it might add signal loss if the cable is cxtremcly
long.
3.0 FM, CW AND NON-LINEAR MODES
Good linearity is the faithful reproduction of input power level changes by the output power of
the amplifier.
Some modulation
methods
or operating modes
do not depend on distortion-free amplitude
changes for transferring information.
Non-linear modes include CW, FM, and FSK.
The
amplifier can "gain compress" or "flat-top" without changing signal quality or bandwidth,
because the RF is either on or off.
This allows the amplifier to be driven to higher output levels with no detectable change in signal
bandwidth.
3.1 DRIVE POWER
Drive power on FM, CW, or FSK is limited by power ratings of transistors and heatsink
temperature.
The transistors are safely able to accept 5 watts of drive, which corresponds to
approximately |10 watts carrier output.
Do not trust unknown or questionable accuracy meters!
Some meters are off by
as much as 50% or more!
3.2 DUTY-CYCLE CW AND FM
The duty-cycle is set by ambient temperature, mounting position, operating power, and airflow.
Temperature and mounting concerns are detailed in section 1.0.
Driving-power concerns are
detailed in section 2.0
If possible, especially if cooling might be marginal and there is no external air blowing across the
heatsink, mount the amplifier with heatsink fins vertical.
This allows natural convection to
circulate air. See section 1.0 for details.
Warning, the safe maximum temperature of the heatsink is 140.
If the heatsink
feels too hot to hold, it is almost certainly too hot for safe operation.
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