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

[Gary Hawkins]

Thanks for the replies relating to JT65-HF and JT9 operation.  I'm 
really hoping to get these modes running because with the high noise 
levels and very limited ability to put up any sort of antenna because of 
our HOA I see these modes as one of the few ways I can enjoy any form of 
DX from the home QTH.

Clearly, the temperature compensation procedure is important for the KX3 
but does it solve the issue completely or is the KX3 still not an ideal 
radio for these modes?

The other consideration I have is ideally I'd like to have the 
capability to transmit in the 10 - 30W power range if necessary to 
operate weaker DX stations.  In an ideal world, I'd pair the KX3 with 
KXPA100 under low drive but if the KX3 is not the right radio for 
JT65/JT9 then perhaps it would be better to buy another JT65/JT9 
out-the-box ready rig for the home shack and keep the KX3 for portable 
ops (around 80 SOTA activations so far and counting).  If you're 
operating JT65/JT9 successfully please let me know your radio/setup offline.

Also, Don thanks for the pointer on the hunting with ALC=0.  I did 
indeed see this but did not mention it in my earlier e-mail as I did not 
want to confuse/complicate the description of the basic problem.

73's Gary K6YOA

On 5/7/2015 12:09 PM, Tony Estep wrote:
> 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 
> <mailto: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
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