[Elecraft] K3 and Expert 1.3K-FA amplifier power

[Bill Frantz]

I have just set up an Expert 1.3K-FA amplifier with my K3 (with 
most of the upgrades to become a K3S). My question is, when I 
drive it with 10W set on the K3 output power, it shows a drive 
level of about 30W and and output level of 950W. What is going on?

Details: The two boxes are connected with about 6' of RG-58 for 
the RF and a custom cable made by KC5PCB, Dan Tassell for the 
rest of the signals. The output is into a dummy load, although 
very similar measurements occur with my trapped vertical 
antenna. Tests were in the CW portion of the 20M band.

The Amp is powered from a dedicated 120V circuit which shows a 7 
volt drop at 12.7A during CW key down transmission. (Voltage is 
measured by a Fluke 87 DVM and current by a Kill-A-Watt PA4400.) 
An external YS-60 power meter shows 800W, which seems reasonable 
agreement given the accuracy of RF power measurements.

Why does the K3 show 10W and the amp show 30W? Is there 
something screwy here, or is it normal?

73 Bill AE6JV

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