K3 - amp plate current wiggles on fsk

[Dave Hachadorian]

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?

Dave Hachadorian, K6LL
Yuma, AZ

















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[Tom Hammond-2]

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

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[dj7mgq]

Hi,

my K3 has always done this, and is, as far as I am concerned, part of  
its personality.

The "couple" of watts "bounciness" has never caused any problems. I've  
always assumed that this might have something to do with the shape of  
the 5 pole 2.7kHz crystal filter.

I use a MicroHam USB Interface, FSK, MTTY and an Apple PowerBook  
runing Windows XP. My K3 is #67.

vy 73 de toby




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