[Elecraft] K1ZTE - KAT500

[KENT TRIMBLE]

Alan is right, but it depends on which "good book" one is consulting!

We have to be careful about transceiver power levels when tuning an 
external AMU, for the sake of the /transceiver /as well as the AMU.

Your AMU may be able to tolerate 100 watts during the tuning process, 
but your transceiver may not.  Unless the transceiver automatically 
folds back its output in the presence of high SWR levels, one risks 
damaging the transceiver's PA transistors.  While many modern rigs do 
so, others, especially older rigs often used by new licensees, do not.

For example, when seeing an SWR above 3:1, my FT-991A reduces its CW 
output from 100 to 10 watts while at the same time flashing "HIGH SWR" 
in red letters.  The rig may be successfully protecting itself, but why 
risk stressing components if it's not necessary?  That's why I prefer 
switching the transceiver to AM at 25 watts when tuning an external AMU.

73,

Kent  K9ZTV



On 9/12/2020 5:16 PM, Alan - G4GNX wrote:
> Although it's preferable to have at least 20W to tune, the good book 
> says that anything between 7 and 100 watts is OK.