2 M Transverter Stabliization

[Edward R Cole]

Chuck,

You may have read that I am waiting delivery of a new 144/28
transverter from DEMI (maybe this week).  It is a prototype
dual-receive unit and there is a possibility it will include an ext.
ref. locking LO.  DEMI is using me as alpha-tester of this
transverter so putting a lot of new stuff in it.

I asked to be a beta-tester for the K3 ext. ref. modification, but
have not received anything.

73, Ed - KL7UW
------------------------------

Message: 22
Date: Sat, 12 Feb 2011 14:51:03 -0700
From: Chuck Smallhouse <[hidden email]>
Subject: [Elecraft] 2 M Transverter Stabliization
To: [hidden email]
Message-ID: <[hidden email]>
Content-Type: text/plain; charset="us-ascii"; format=flowed

Wayne, Eric,

I'm referring to some concerns described by inputs to the Elecraft
Reflector, about not only the stability but also L.O. calibration of
the 2 M xvrtr, K144XV and probably the XV144.   I wonder if in the
near future you might consider phase locking their L.O.s to a 10 MHz
OCXO.  I understand that there are some Beta units in the field that
are locking the K3's TCXO to 10 MHz (when can I get one?).  It would
also be great if you could do the same for your 2M xvrtrs, so that
they could be synched to the same stable source.

Many of us VHF/UHF/Microwave weak signal and EME
experimenters/operators, are now phase locking (via a 10 MHz source)
our xvrtrs to those upper bands, most of which use a 2 M IF.  At
present I don't believe that there are any other manufactures or
vendors doing this yet, for 2 M xvrtrs.  It would really be a boon to
have a self contained, ultra stable and accurate, 2M IF system the
quality of a K3.

Chuck,  W7CS



73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 144-1.4kw*, 432-100w*, 1296-testing*, 3400-winter?
DUBUS Magazine USA Rep [hidden email]
======================================
*temp not in service
______________________________________________________________
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

[W7CS]

Wayne, Eric,

I'm referring to some concerns described by inputs to the Elecraft
Reflector, about not only the stability but also L.O. calibration of
the 2 M xvrtr, K144XV and probably the XV144.   I wonder if in the
near future you might consider phase locking their L.O.s to a 10 MHz
OCXO.  I understand that there are some Beta units in the field that
are locking the K3's TCXO to 10 MHz (when can I get one?).  It would
also be great if you could do the same for your 2M xvrtrs, so that
they could be synched to the same stable source.

Many of us VHF/UHF/Microwave weak signal and EME
experimenters/operators, are now phase locking (via a 10 MHz source)
our xvrtrs to those upper bands, most of which use a 2 M IF.  At
present I don't believe that there are any other manufactures or
vendors doing this yet, for 2 M xvrtrs.  It would really be a boon to
have a self contained, ultra stable and accurate, 2M IF system the
quality of a K3.

Chuck,  W7CS

______________________________________________________________
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

[David Pratt]

As far as I know, Chuck, Wayne has this in hand.

My own K144XV is unusable because of the amount of frequency drift I am
getting.  If I do use my K144XV I find that I am repeatedly having to
apologise for Elecraft. It drifts almost 100Hz for every 5 minutes I
transmit. This might be okay for FM, but certainly not for other modes.

73 de David G4DMP

In a recent message, Chuck Smallhouse <[hidden email]> writes
>
>I'm referring to some concerns described by inputs to the Elecraft
>Reflector, about not only the stability but also L.O. calibration of
>the 2 M xvrtr, K144XV and probably the XV144.   I wonder if in the
>near future you might consider phase locking their L.O.s to a 10 MHz
>OCXO.  I understand that there are some Beta units in the field that
>are locking the K3's TCXO to 10 MHz (when can I get one?).  It would
>also be great if you could do the same for your 2M xvrtrs, so that
>they could be synched to the same stable source.



______________________________________________________________
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

[John Ragle]

     I recently built an XV144, and the LO was badly out of calibration.
The crystal is marked 116.000, but the offset was about 15 kHz, totally
uncorrectable with the K3 --> CONFIG --> XV 1 OFS, which manages +/-
9.99 kHz. Elecraft quickly shipped me a "mod" which consists of a small,
variable, inductor that goes in the RF circuit board at L19. In
addition, I invested in the crystal oven, since my experience with the
crystal oven in my ICOM910H has been quite satisfactory. This adds < $50
to the purchase price of the XV144 kit.

     With the inductor at L19 (remember to remove the jumper by C65!)
and with the oven in place, the offset is well within range of the K3
adjustment. My casual observation is that the drift in the LO frequency
is completely negligible. This observation stems from the fact that I
was checked in to a New England net for about 45 minutes at 144.250 and
noticed no change in dial setting for reception of the NCS. The
instructions that come with the mod kit L19 suggest beginning with the
top of the tuning slug flush with the top of the coil form. I found this
setting to be quite critical, and ended up about 3/4 of a turn further
out than suggested, with K3 --> CONFIG --> XV1 OFS set to 2.50 and a
frequency counter reading of 144.25000 when the K3 dial was set to
144.250. I have the J9 jumpers set so that the oven is ON when ever the
K3 is on, and my K3 is on from about 6 AM to about 10 PM continuously,
every day.

     I think the oven and L19 solve the two problems of drift and
offset, at least in my XV144. I get ~20 W maximum from this XV144.

John Ragle -- W1ZI

=====

On 2/12/2011 5:18 PM, David Pratt wrote:

> As far as I know, Chuck, Wayne has this in hand.
>
> My own K144XV is unusable because of the amount of frequency drift I am
> getting.  If I do use my K144XV I find that I am repeatedly having to
> apologise for Elecraft. It drifts almost 100Hz for every 5 minutes I
> transmit. This might be okay for FM, but certainly not for other modes.
>
> 73 de David G4DMP
>
> In a recent message, Chuck Smallhouse<[hidden email]>  writes
>> I'm referring to some concerns described by inputs to the Elecraft
>> Reflector, about not only the stability but also L.O. calibration of
>> the 2 M xvrtr, K144XV and probably the XV144.   I wonder if in the
>> near future you might consider phase locking their L.O.s to a 10 MHz
>> OCXO.  I understand that there are some Beta units in the field that
>> are locking the K3's TCXO to 10 MHz (when can I get one?).  It would
>> also be great if you could do the same for your 2M xvrtrs, so that
>> they could be synched to the same stable source.
>
>
> ______________________________________________________________
> 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

[David Pratt]

Like you, John, I find the XV144 to be extremely stable after allowing a
few minutes for the oven to attain its operating temperature. I get the
correct offset without the need for any additional inductance to pull
the crystal.

A modification I have made though is to add a cooling fan similar to
that fitted to the XV432.  My XV144 is an early model, so I also drilled
vent holes in the top and bottom covers. I believe these are now
standard in later XV144 kits.

73 de David G4DMP

In a recent message, John Ragle <[hidden email]> writes
>
>     I think the oven and L19 solve the two problems of drift and
>offset, at least in my XV144. I get ~20 W maximum from this XV144.
--
 + - - - - - - - - - - - - - - - - +
 | David M Pratt, Kippax, Leeds.   |
 | Website: http://www.g4dmp.co.uk |
 + - - - - - - - - - - - - - - - - +



______________________________________________________________
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