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KTCXO3-1 TCXO

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Edward R Cole

KTCXO3-1 TCXO

Date: Sun, 3 Feb 2013 08:45:36 -0600
From: Chad Wasinger <[hidden email]>
To: "[hidden email]" <[hidden email]>
Subject: [Elecraft] KTCXO3-1 TCXO
Message-ID: <[hidden email]>
Content-Type: text/plain; charset="iso-8859-1"

Does anyone know the approximate warm-up/stabilize time of the KTCXO3-1?
Thanks,ChadN0YK
----------------
Chad,

I observed the action of my TCXO3-1 closely after initial
installation of the EXREF. I noted from cold start up that the TCXO
was receiving a continued updated offset for about 20 to 30 minutes,
whereby it stabilized out at about an offset of about 78-80. From
that time on the offset would only wander a couple points over several minutes.

A check of my 28-MHz transmit frequency accuracy was within 2-Hz
(indicating 0.1 ppm) and would only occasionally change by 1-Hz
reflecting the slow drift of the TCXO between reference checks with
the external 10-MHz source. Running the TCXO-3 without the EXREF
accuracy is aprox. 0.5ppm or on 28-MHz this translates to a maximum
error of +/- 14-Hz.

Freq. measurements are made with an EIP-538 microwave counter that is
referenced to a Rubidium 10-MHz reference. The K3EXREF is referenced
to a separate OCXO which is run on a battery full-time. Short-term
stability of the OCXO is +/-5 E-12, Long-term stability is +/-5 E-5
which requires adjustment about every four months to correct about
1-Hz long-term drift. I have a 200K ten-turn helipot for adjusting
the OCXO frequency. I use my Rubidium as frequency reference which
is +/- 5 E-11 after 30-min warmup. GPS is more accurate but I find
the Rubidium sufficient for my needs. eg: 10-MHz is 1.0 E+7,
multiplied by 5 E-11 = 5.0 E-4 Hz = 0.0005 Hz

See details of the EXREF (and TCXO3-1):
http://www.kl7uw.com/K3EXREF.htm

73, Ed - KL7UW

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Chad Wasinger

Re: KTCXO3-1 TCXO

Thanks you all for responding to this. I also note that it takes around an hour for the larger corrections to settle down and several hours for complete stability to set in.
I've been monitoring my front panel temperature sensor which normally runs 36 C with the radio on for several hours and a shack temperature of 75 F degrees. From a cold start up at 24 C, it normally takes about an hour to reach a constant temperature of 36 C on the FP. I know the FP temp reading and TCXO are separate pieces but at the point of 36 C, I have really notice the TCXO to settle out.

> Date: Sun, 3 Feb 2013 09:22:57 -0900
> To: [hidden email]
> From: [hidden email]
> Subject: [Elecraft] KTCXO3-1 TCXO
>
> Date: Sun, 3 Feb 2013 08:45:36 -0600
> From: Chad Wasinger <[hidden email]>
> To: "[hidden email]" <[hidden email]>
> Subject: [Elecraft] KTCXO3-1 TCXO
> Message-ID: <[hidden email]>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Does anyone know the approximate warm-up/stabilize time of the KTCXO3-1?
> Thanks,ChadN0YK
> ----------------
> Chad,
>
> I observed the action of my TCXO3-1 closely after initial
> installation of the EXREF. I noted from cold start up that the TCXO
> was receiving a continued updated offset for about 20 to 30 minutes,
> whereby it stabilized out at about an offset of about 78-80. From
> that time on the offset would only wander a couple points over several minutes.
>
> A check of my 28-MHz transmit frequency accuracy was within 2-Hz
> (indicating 0.1 ppm) and would only occasionally change by 1-Hz
> reflecting the slow drift of the TCXO between reference checks with
> the external 10-MHz source. Running the TCXO-3 without the EXREF
> accuracy is aprox. 0.5ppm or on 28-MHz this translates to a maximum
> error of +/- 14-Hz.
>
> Freq. measurements are made with an EIP-538 microwave counter that is
> referenced to a Rubidium 10-MHz reference. The K3EXREF is referenced
> to a separate OCXO which is run on a battery full-time. Short-term
> stability of the OCXO is +/-5 E-12, Long-term stability is +/-5 E-5
> which requires adjustment about every four months to correct about
> 1-Hz long-term drift. I have a 200K ten-turn helipot for adjusting
> the OCXO frequency. I use my Rubidium as frequency reference which
> is +/- 5 E-11 after 30-min warmup. GPS is more accurate but I find
> the Rubidium sufficient for my needs. eg: 10-MHz is 1.0 E+7,
> multiplied by 5 E-11 = 5.0 E-4 Hz = 0.0005 Hz
>
> See details of the EXREF (and TCXO3-1):
> http://www.kl7uw.com/K3EXREF.htm
>
> 73, Ed - KL7UW
>
> ______________________________________________________________
> 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

______________________________________________________________
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Post: mailto:[hidden email]

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Chad Wasinger

Re: KTCXO3-1 TCXO

Side question: Does anyone know the exact location of the temperature sensor for the FP reading on the K3?

> From: [hidden email]
> To: [hidden email]; [hidden email]
> Date: Mon, 4 Feb 2013 09:24:44 -0600
> Subject: Re: [Elecraft] KTCXO3-1 TCXO
>
> Thanks you all for responding to this. I also note that it takes around an hour for the larger corrections to settle down and several hours for complete stability to set in.
> I've been monitoring my front panel temperature sensor which normally runs 36 C with the radio on for several hours and a shack temperature of 75 F degrees. From a cold start up at 24 C, it normally takes about an hour to reach a constant temperature of 36 C on the FP. I know the FP temp reading and TCXO are separate pieces but at the point of 36 C, I have really notice the TCXO to settle out.
> > Date: Sun, 3 Feb 2013 09:22:57 -0900
> > To: [hidden email]
> > From: [hidden email]
> > Subject: [Elecraft] KTCXO3-1 TCXO
> >
> > Date: Sun, 3 Feb 2013 08:45:36 -0600
> > From: Chad Wasinger <[hidden email]>
> > To: "[hidden email]" <[hidden email]>
> > Subject: [Elecraft] KTCXO3-1 TCXO
> > Message-ID: <[hidden email]>
> > Content-Type: text/plain; charset="iso-8859-1"
> >
> > Does anyone know the approximate warm-up/stabilize time of the KTCXO3-1?
> > Thanks,ChadN0YK
> > ----------------
> > Chad,
> >
> > I observed the action of my TCXO3-1 closely after initial
> > installation of the EXREF. I noted from cold start up that the TCXO
> > was receiving a continued updated offset for about 20 to 30 minutes,
> > whereby it stabilized out at about an offset of about 78-80. From
> > that time on the offset would only wander a couple points over several minutes.
> >
> > A check of my 28-MHz transmit frequency accuracy was within 2-Hz
> > (indicating 0.1 ppm) and would only occasionally change by 1-Hz
> > reflecting the slow drift of the TCXO between reference checks with
> > the external 10-MHz source. Running the TCXO-3 without the EXREF
> > accuracy is aprox. 0.5ppm or on 28-MHz this translates to a maximum
> > error of +/- 14-Hz.
> >
> > Freq. measurements are made with an EIP-538 microwave counter that is
> > referenced to a Rubidium 10-MHz reference. The K3EXREF is referenced
> > to a separate OCXO which is run on a battery full-time. Short-term
> > stability of the OCXO is +/-5 E-12, Long-term stability is +/-5 E-5
> > which requires adjustment about every four months to correct about
> > 1-Hz long-term drift. I have a 200K ten-turn helipot for adjusting
> > the OCXO frequency. I use my Rubidium as frequency reference which
> > is +/- 5 E-11 after 30-min warmup. GPS is more accurate but I find
> > the Rubidium sufficient for my needs. eg: 10-MHz is 1.0 E+7,
> > multiplied by 5 E-11 = 5.0 E-4 Hz = 0.0005 Hz
> >
> > See details of the EXREF (and TCXO3-1):
> > http://www.kl7uw.com/K3EXREF.htm
> >
> > 73, Ed - KL7UW
> >
> > ______________________________________________________________
> > 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
>
> ______________________________________________________________
> 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