[Elecraft] Elecraft K2/100 in RTTY and PSK31 Modes

[Charles Greene]

Hi,

I don't have a K2/100 but just a K2 which I use for PSK31 and RTTY, but the 
same principles apply in power dissipation in the final amplifiers.  There 
is a difference in the power you can safely run while using RTTY and 
PSK31.  RTTY uses a single tone and thus the final amplifier efficiency is 
a theoretical 82% efficiency when running in the linear mode.  When 
amplifying two tones which is what PSK31 is when in idle, the theoretical 
efficiency of the same amplifier is on the order of 62% efficiency.  So to 
keep the power dissipation the same in RTTY you need to reduce the power 
output.  100 watts power output at 82% efficiency gives a dissipation of 
about 22 watts.  36 watts power output at 62% efficiency also gives a 
dissipation of about 22 watts.  An additional fan is a good idea.


73, Chas, W1CG
K2 #462B