[Elecraft] [KX3] JT65 and JT9 possible TX issues

[Tony Estep]

Gary, I would certainly say that you should do the temp compensation
process, notwithstanding your enhanced heat sink. I did a bunch of careful
tests with my KX3 a couple of years ago. In fact, those results were part
of the early motivation for the development of the compensation process.
You can do them yourself if you have another radio that can receive JT65 or
WSPR. Just run the KX3 into a dummy load and watch the trace showing its
xmit frequency on the other radio. In my case, there was a short burst of
drift of about 18 hz right after transmit started. This was pretty much
independent of the selected power output.

Trying to use the KX3 for JT65 qsos, I got results exactly like yours. I
could receive, and occasionally make a contact, but not often, and some
contacts broke off in the middle.

The heat sink will cool the output stage but my results seem to say that
heating is also causing a bit of drift somewhere else. All this is
evidently fixed by the refrigerator/heat-gun procedure devised by Elecraft.
Try it, and I think you'll be up and going.

73,
Tony KT0NY

On Thu, May 7, 2015 at 12:11 PM, Gary Hawkins <gary at hawkins-zhu.com> wrote:

> I've successfully setup my KX3 with HRD 5.4.28 and WSJT-X, using a
> Signalink to interface audio to computer (my first attempt at digital
> operation).
>
> Everything seems to work well on receive, and I can hear and decode a good
> number of stations in both modes (WSJT-X will do simultaneous decode of
> both JT65 and JT9 with BW set to 4kHz).
>
> While TX is functioning (running 3W, ALC=0, have not done temp
> compensation but have VE7FMN heatsink), reception by other parties has been
> difficult.  Using JT65-HF I've had a couple of incomplete QSOs - the
> receiving station has been able to decode and respond at least initially.
> Using JT9 the one station I contacted reported unable to decode, after
> trying on several different occasions/times.
>
> So my questions are what are the capabilities of the KX3 in this
> configuration for these modes, i.e. running at 3W and with heatsink
> fitted?  Should I expect the KX3 to be able to function in both modes TX
> without issue, particularly relating to internal heat build-up, freq
> stability)?  Any thoughts on likely issue - pls ask for more details of
> setup if required?
>
> 73's Gary K6YOA
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to esteptony at gmail.com
>