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[KX3] JT65 and JT9 possible TX issues

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Gary Hawkins

[KX3] JT65 and JT9 possible TX issues

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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Stephen Shearer

Re: [KX3] JT65 and JT9 possible TX issues

I have used KX3 for JT65 at 0.5 watts.
1. you need ALC = 4-5 bars. I think it in the manual about digital modes.
I use WSJTX directly. Audio into an external USB sound "card" (I don't
like transmitting system sounds...)
I use USB control cable (same as used with KX3 utility) with rig control
from WSJTX.

73, steve WB3LGC

On 07-May-15 1:11 PM, Gary Hawkins 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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Don Wilhelm-4

Re: [KX3] JT65 and JT9 possible TX issues

In reply to this post by Gary Hawkins

Gary,

You need to increase the audio drive to produce 4 bars solid on the
"ALC" meter with the 5th bard flickering.
The KX3 "ALC" meter shows the relative audio level in the 1st 4 bars -
this is not actually ALC activity, but more like a VU meter.
The onset of ALC is indicated by the 5th bar and above.

Do not attempt to control the KX3 power output with the audio input -
run the audio input full and adjust the desired power level with the
power knob. I know that is different from the conventional advice given
for other transceivers, but the way the KX3 controls power is different
from the power control mechanism on other amateur transceivers. If you
do not drive the KX3 audio fully, the power control circuits will "power
hunt".

73,
Don W3FPR

On 5/7/2015 1:11 PM, Gary Hawkins wrote:

Jim Brown-10

Re: [KX3] JT65 and JT9 possible TX issues

Additional advice from the Elecraft guys. The KX3 has two operating
ranges, with the transition at 3W. It is most efficient on the low side
of that transition. To find that "sweet spot," slowing increase the
power to just above 3W, listening carefully for a relay click, then back
off the power until you hear it click again.

This matters both for battery drain, and for heating with keydown modes
like JT65.

For JT65 on the higher frequency bands, especially 6M, it's important to
perform the temperature calibration procedure documented on the Elecraft
website.

K1JT does not recommend JT9 on 6M for reasons of frequency stability,
but I've successfully used JT9 on 6M with my K3.

73, Jim K9YC

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Ross Primrose

Re: [KX3] JT65 and JT9 possible TX issues

On 5/7/2015 2:38 PM, Jim Brown wrote:
> K1JT does not recommend JT9 on 6M for reasons of frequency stability,
> but I've successfully used JT9 on 6M with my K3.
>
> 73, Jim K9YC
>

With the factory TCXO, or the high-stability one?

73, Ross N4RP

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--
FCC Section 97.313(a) “At all times, an amateur station must use the minimum transmitter power necessary to carry out the desired communications.”

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Jim Brown-10

Re: [KX3] JT65 and JT9 possible TX issues

His advice is not specific to Elecraft products. Lots of WSJT operators
use vastly inferior radios. Think IC706, FT897, etc. Obviously, it's
less of an issue with better radios on both ends. :)

73, Jim K9YC

On Thu,5/7/2015 11:50 AM, Ross Primrose wrote:
> On 5/7/2015 2:38 PM, Jim Brown wrote:
>> K1JT does not recommend JT9 on 6M for reasons of frequency stability,
>> but I've successfully used JT9 on 6M with my K3.
>>
>> 73, Jim K9YC
>>
>
> With the factory TCXO, or the high-stability one?

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Ross Primrose

Re: [KX3] JT65 and JT9 possible TX issues

Yeah, I knew that. I was asking if YOU have the factory TCXO or the
upgraded one in your K3...

73, Ross N4RP

On 5/7/2015 3:01 PM, Jim Brown wrote:

> His advice is not specific to Elecraft products. Lots of WSJT
> operators use vastly inferior radios. Think IC706, FT897, etc.
> Obviously, it's less of an issue with better radios on both ends. :)
>
> 73, Jim K9YC
>
> On Thu,5/7/2015 11:50 AM, Ross Primrose wrote:
>> On 5/7/2015 2:38 PM, Jim Brown wrote:
>>> K1JT does not recommend JT9 on 6M for reasons of frequency
>>> stability, but I've successfully used JT9 on 6M with my K3.
>>>
>>> 73, Jim K9YC
>>>
>>
>> With the factory TCXO, or the high-stability one?
>
> ______________________________________________________________
> Elecraft mailing list
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>
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--
FCC Section 97.313(a) “At all times, an amateur station must use the minimum transmitter power necessary to carry out the desired communications.”

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Tony Estep

Re: [KX3] JT65 and JT9 possible TX issues

In reply to this post by Gary Hawkins

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 <[hidden email]> 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:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Gary Hawkins

Re: [KX3] JT65 and JT9 possible TX issues

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 <[hidden email]
> <mailto:[hidden email]>> 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:[hidden email]
> <mailto:[hidden email]>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email] <mailto:[hidden email]>
>
>

Jim Brown-10

Re: [KX3] JT65 and JT9 possible TX issues

On Thu,5/7/2015 7:15 PM, Gary Hawkins wrote:
> 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).

The ONLY shortcoming of the KX3 for JT65/JT9 is heating during the long
TX cycle, which in practice limits its output to about 3W, and you want
an aftermarket heat sink. Use that 3W to drive a KXPA100 to about 60W,
and you've got an excellent radio. You would need to move up to a K3 to
get better. and 60W is a LOT on JT65 and JT9. More power than that is
used only on 160M, 6M, and weak signal modes like moonbounce. On HF,
most JT65/JT9 is in the range of 5-30W.

Temperature stability is only an issue on 6M and above.

73, Jim K9YC

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Neil Zampella

Re: [KX3] JT65 and JT9 possible TX issues

FWIW ... I did the temperature compensation routine and added an
aftermarket heatsink to my KX3. I can transmit JT65 at 10 w without
hitting the HiTemp issue. I decided to add some additional cooling, so
I yanked an old 12v CPU cooler out of one of the old desktop computer
cases I have laying around, soldered on a few powerpole connectors, and
have that sitting on top of the KX3 to provide extra cooling. No
HiTemp problems on JT9 with that running at all.

At 5 to 10 watts, I've hit all continents except for Asia, and that's
more an issue with my antenna than with the radio, as I can QSO with
Australia at 5 w on JT65 if I hear them. This is from Southwest PA
near Pittsburgh.

Neil
KN3ILZ

On 05/07/15 11:27 pm, Jim Brown wrote:

> On Thu,5/7/2015 7:15 PM, Gary Hawkins wrote:
>> 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).
>
> The ONLY shortcoming of the KX3 for JT65/JT9 is heating during the
> long TX cycle, which in practice limits its output to about 3W, and
> you want an aftermarket heat sink. Use that 3W to drive a KXPA100 to
> about 60W, and you've got an excellent radio. You would need to move
> up to a K3 to get better. and 60W is a LOT on JT65 and JT9. More power
> than that is used only on 160M, 6M, and weak signal modes like
> moonbounce. On HF, most JT65/JT9 is in the range of 5-30W.
>
> Temperature stability is only an issue on 6M and above.
>
> 73, Jim K9YC
>
>
>
>
>

Elecraft mailing list

Re: [KX3] JT65 and JT9 possible TX issues

Just curious how is the New and improved Stock Heatsink from Elecraft?

I just got my KX3 and have not had time to try it out in the digital modes

From: Neil Zampella <[hidden email]>
To: [hidden email]
Sent: Saturday, May 9, 2015 10:48 AM
Subject: Re: [Elecraft] [KX3] JT65 and JT9 possible TX issues

FWIW ... I did the temperature compensation routine and added an
aftermarket heatsink to my KX3. I can transmit JT65 at 10 w without
hitting the HiTemp issue. I decided to add some additional cooling, so
I yanked an old 12v CPU cooler out of one of the old desktop computer
cases I have laying around, soldered on a few powerpole connectors, and
have that sitting on top of the KX3 to provide extra cooling. No
HiTemp problems on JT9 with that running at all.

At 5 to 10 watts, I've hit all continents except for Asia, and that's
more an issue with my antenna than with the radio, as I can QSO with
Australia at 5 w on JT65 if I hear them. This is from Southwest PA
near Pittsburgh.

Neil
KN3ILZ

On 05/07/15 11:27 pm, Jim Brown wrote:

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