[Elecraft] K3 - amp plate current wiggles on fsk

[Tom Hammond]

Hi Dave:

>I made a few contacts in the cqww rtty today with a K3. Everything 
>seemed to work fb, but I noticed the amplifier plate current 
>wiggling with FSK modulation. I never noticed this with my old 
>TS-850. I hooked up a hand key to the K3 FSK jack, and when the key 
>went down, there was a short power excursion upwards. When the key 
>went up, there was a short power excursion downwards. The final 
>power was the same after these excursions settled out (about 0.5 
>second). The power excursions were about 100 watts out of 1500.
>
>Operationally this is no big deal, but I wonder if there are 
>transients being generated. Has anyone else noticed this?

Yesterday afternoon, I decided to give a CQWW RTTY Q to a local (W4RK) who had
been toiling long and hard in the contest.

I don't have ANY(!) RTTY software on hand, so I programmed the K3's M1 and M2
with an answer to someone's CQ (M1) and the appropriate exchange (M2), and then
send the station's call in CW, using the CW-to-RTTY conversion facility.

I was driving my Alpha 76PA to about 700W output with about 25W from the K3.

I noticed no(!) variation output of the amp at any time during the 50 (or so)
Q's I made (in order to ensure that's I'd not appear as a UNIQUE in 
W4RK's log).
I was working stations as fast as I could tune 'em in and ID the 
decoded call...!

I watched the RF output envelope closely on an SM-220 monitor scope AND on an
LP-100A wattmeter (from N8LP, thanks Larry). No RX-to-RX or TX-to-RX anomalies
were noted.  I operated on both 20M and 15M.

Oh... I never did find W4RK to give him that QSO... turns out that while I was
looking for him, he was outside, working on the house... heheheh!  Figgers!

73,

Tom   N0SS