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JT65 with KX3

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jh3sif

JT65 with KX3

I am experiencing some frequency drift on operating JT65 with KX3 + KXPA100. I was reported that my signal drifted 5 to 8Hz drift during my transmission and noticed almost same amount of drift during my receiving period.
Output power was 20W with KXPA100. OSC temp shows 36C on receiving and 39C on transmitting.
I want to know if someone have similar experience before talking to Elecraft support team.

73 de JH3SIF, Keith

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Don Wilhelm

Re: JT65 with KX3

Keith,

Have you done the Extended Temperature Compensation procedure on that KX3?
If not, you should do that. It should reduce that drift due to
temperature significantly.

73,
Don W3FPR

On 4/25/2016 6:34 PM, Keith Onishi wrote:
> I am experiencing some frequency drift on operating JT65 with KX3 + KXPA100. I was reported that my signal drifted 5 to 8Hz drift during my transmission and noticed almost same amount of drift during my receiving period.
> Output power was 20W with KXPA100. OSC temp shows 36C on receiving and 39C on transmitting.
>

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Jim Rodenkirch

Re: JT65 with KX3

In reply to this post by jh3sif

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ve3ibw

Re: JT65 with KX3

In reply to this post by Don Wilhelm

I would agree with the ext temp compensation. It is the right thing to do
and let's the onboard computer handle the drift variations for you. I
don't have the xg50, which is recommended. I tried the wwv approach and
that did not work, even when wwv was coming in fairly strong at s7. I
watched the collection on the kx3utility and it was good on the third try,
no gaps or fades that caused the beat frequency to be read incorrectly.

However, I have returned to the standard compensation as opposed to what I
attempted to do with wwv and the extended temp compensation. I did it
three times and all results were worse than the standard.

I will try to build a stable frequency oscillator or perhaps purchase the
xg50 so I can do the temp compensation properly. The standard
compensation seems to work ok. There is still drift, but not as bad. Once
the oscillator has warmed up, the standard compensation seems to do a
decent job. But, my experience is like yours, I can see the drift on the
wsjtx program waterfall and in some cases it is 8-11hz. I have to pay
attention when I run wsjtx as the person I am calling may not answer me on
the frequency I answered them on.

P.S. My clock is set from the Internet and I am not sure how that equates
to drift that one sees on the waterfall. Most of those I return a call to
are only out by 0.2 - 1.2 seconds. The clock sync doesn't seem to have
anything to do with drift that one sees on the waterfall. But I am
prepared to be educated if someone can demonstrate drift to time sync
correlation.

Regards
Brian
VE3IBW

On Monday, 25 April 2016, Don Wilhelm <[hidden email]> wrote:

> Keith,
>
> Have you done the Extended Temperature Compensation procedure on that KX3?
> If not, you should do that. It should reduce that drift due to
> temperature significantly.
>
> 73,
> Don W3FPR
>
> On 4/25/2016 6:34 PM, Keith Onishi wrote:
>
>> I am experiencing some frequency drift on operating JT65 with KX3 +
>> KXPA100. I was reported that my signal drifted 5 to 8Hz drift during my
>> transmission and noticed almost same amount of drift during my receiving
>> period.
>> Output power was 20W with KXPA100. OSC temp shows 36C on receiving and
>> 39C on transmitting.
>>
>>
> ______________________________________________________________
> 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]
>

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Regards,
Brian
VE3IBW

Edward R Cole

Re: JT65 with KX3

In reply to this post by jh3sif

I ran the KX3 temp compensation procedure twice (the first run was a
learning experience so feel I got a good run on #2). I used my AG3
coupled with a very good freq counter.

JT65 is a synchronous code so that demands good frequency control
(<+/- 10 Hz) and near perfect timing (< 1 second). Both are
essential to good decodes of very weak signals. There is no casual
relationship between them. If either is off very much signals are not decoded.

I just performed frequency calibration for one of my transverter
customers and got the 144-MHz transverter within 3-Hz (tuned heated
xtal osc.). The K3 shows frequency within 1-Hz at 28-MHz (using
EXREF + ext OCXO). Both were run for two hours before calibrating.

73, Ed - KL7UW
http://www.kl7uw.com
"Kits made by KL7UW"
Dubus Mag business:
[hidden email]

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Don Wilhelm

Re: JT65 with KX3

In reply to this post by ve3ibw

Brian,

The XG50 is not really expensive and is a good stable source. It is
'cheap' compared to the frustration factor involved with trying to use
other methods.
If you have access to an instrument lab with highly stable signal
sources in the 50MHz range, then you are all set, but most are not so
fortunate.

The problem in justifying the price is that it is seldom used once you
do the KX3 calibration. Maybe we should create a 'ham sharing XG50'
network to allow each to pay a portion of the total cost of the XG50.
That would work fine if you have several locals with a KX3 - check with
your local club.

73,
Don W3FPR

On 4/26/2016 3:37 PM, Brian Waterworth wrote:

> I would agree with the ext temp compensation. It is the right thing to do
> and let's the onboard computer handle the drift variations for you. I
> don't have the xg50, which is recommended. I tried the wwv approach and
> that did not work, even when wwv was coming in fairly strong at s7. I
> watched the collection on the kx3utility and it was good on the third try,
> no gaps or fades that caused the beat frequency to be read incorrectly.
>
> However, I have returned to the standard compensation as opposed to what I
> attempted to do with wwv and the extended temp compensation. I did it
> three times and all results were worse than the standard.
>
> I will try to build a stable frequency oscillator or perhaps purchase the
> xg50 so I can do the temp compensation properly.

Edward R Cole

Re: JT65 with KX3

In reply to this post by jh3sif

Don and Brian:

I had good luck just using my XG3 as signal source for the temp
compensation on 50-MHz.
I did monitor freq on my prof. counter.

73, Ed - KL7UW

From: Don Wilhelm <[hidden email]>
To: [hidden email]
Subject: Re: [Elecraft] JT65 with KX3
Message-ID: <[hidden email]>
Content-Type: text/plain; charset=windows-1252; format=flowed

Brian,

The XG50 is not really expensive and is a good stable source. It is
'cheap' compared to the frustration factor involved with trying to use
other methods.
If you have access to an instrument lab with highly stable signal
sources in the 50MHz range, then you are all set, but most are not so
fortunate.

The problem in justifying the price is that it is seldom used once you
do the KX3 calibration. Maybe we should create a 'ham sharing XG50'
network to allow each to pay a portion of the total cost of the XG50.
That would work fine if you have several locals with a KX3 - check with
your local club.

73,
Don W3FPR

73, Ed - KL7UW
http://www.kl7uw.com
"Kits made by KL7UW"
Dubus Mag business:
[hidden email]

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Michael Walker

Re: JT65 with KX3

Before you blame the radio for drifting, how do you know your sound card
isn't drifting?

The problem looks the same. There are many tests you can run when
referencing WWV and watching the drift.

This is one of the many tools:
http://www.qsl.net/dl4yhf/speclab/frqcalib.htm

Or: https://www.stu2.net/wiki/index.php/Calibrate_Sound_Card

Mike va3mw

On Wed, Apr 27, 2016 at 12:59 PM, Edward R Cole <[hidden email]> wrote:

> Don and Brian:
>
> I had good luck just using my XG3 as signal source for the temp
> compensation on 50-MHz.
> I did monitor freq on my prof. counter.
>
> 73, Ed - KL7UW
>
> From: Don Wilhelm <[hidden email]>
> To: [hidden email]
> Subject: Re: [Elecraft] JT65 with KX3
> Message-ID: <[hidden email]>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> Brian,
>
> The XG50 is not really expensive and is a good stable source. It is
> 'cheap' compared to the frustration factor involved with trying to use
> other methods.
> If you have access to an instrument lab with highly stable signal
> sources in the 50MHz range, then you are all set, but most are not so
> fortunate.
>
> The problem in justifying the price is that it is seldom used once you
> do the KX3 calibration. Maybe we should create a 'ham sharing XG50'
> network to allow each to pay a portion of the total cost of the XG50.
> That would work fine if you have several locals with a KX3 - check with
> your local club.
>
> 73,
> Don W3FPR
>
>
>
> 73, Ed - KL7UW
> http://www.kl7uw.com
> "Kits made by KL7UW"
> Dubus Mag business:
> [hidden email]
>
> ______________________________________________________________
> 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]
>