[Elecraft] KPA100 recommended max power for digital modes?

[Richard Ferch]

On 2/21/2014 7:43 PM, WA7SPY wrote:
 > What is the recommended max power setting for the amp using PSK31 
with a KX3?

In the K3, the limiting factor in some digital modes (notably PSK) is 
not thermal capability of the radio or amplifier, it is linearity. The 
linearity limit depends on the particular digital mode in use, and it 
may also vary depending on the mode used in the radio. For PSK31 and its 
higher-speed brethren, using the radio's DATA A mode, power settings no 
higher than half the maximum power rating of the transmitter should be 
used. This will ensure that the maximum instantaneous peaks of the 
transmitted signal are not clipped (in PSK these peaks can be up to 
twice as high as the average transmitted power). I can't speak from 
personal experience for the KX3, but given the similarity in the way the 
transmitter power is controlled, I would expect it to be the same as the 
K3. Using the KXPA100, keeping the power setting below 50 watts should 
avoid non-linearity.

73,
Rich VE3KI