[Elecraft] K3 FSK power transients

[Richard Ferch]

Hi Dave,

Have you tried AFSK instead? If so, do you see similar power transients? 
Depending on what software is generating the tones and assuming the 
audio level is set properly, it is possible that AFSK might produce a 
cleaner signal than what you are seeing in FSK. Operationally, they are 
the same, i.e. all the same features and operating techniques that you 
use in FSK D can also be used in AFSK A (well, except maybe for using CW 
paddles to transmit - that doesn't work in AFSK A).

Just another idle thought, but I wonder whether the TX Gain calibration 
would make a difference?

When I try FSK I don't see any sign of similar transients, but my power 
metering might not be able to respond quickly enough to see them if they 
were there, so that doesn't necessarily mean a lot.

73,
Rich VE3KI


Dave Hachadorian K6LL wrote:

> I'm getting my K3's set up for the CQWW DX RTTY, and notice 
> that there is a significant variation in power output 
> whenever the FSK goes from mark to space or space to mark. 
> One of these K3's is driving a high gain tetrode amp, and 
> the amp's screen current is jumping all over the place. The 
> power transient is only at the time of transition. The 
> steady-state power of the mark and space are equal.
> 
> I've complained about this before, but it seems to be even 
> worse now. I'm using FW rev 3.30.
> 
> This amplitude modulation has got to be producing some 
> illegal sidebands.
> 
> Dave Hachadorian, K6LL
> Yuma, AZ