[Elecraft] XV Transverter Local Oscillator -- GPSDO?

[Carol F. Milazzo, KP4MD/W6]

As I added the insulation and fan modifications just to stabilize the
internal 116 MHz local oscillator, I feel certain that they are not
necessary when using a GPS disciplined LO like N5AC's VHF ApolLO.  That was
an alternative I did consider before our own group project GPS10 became
available.  I would have fed the 10 MHz signal through the AUX BNC
connector to a VHF ApolLO installed inside the Elecraft XV144 case.
 Anyway, I have left the fans running as I like to see the Elecraft
transverter run cool.

Carol

On Tue, Jul 2, 2013 at 8:59 AM, Bill Schwantes <bill4070 at gmail.com> wrote:

> Carol,
>
> You've done some nice work here, by identifying XV temperature sensitive
> oscillator components other than the crystal.
>
> I'm curious to see if the demonstrated stability could be reproduced
> without the insulation and fan modifications you made...... just the GPS
> disciplined 116 Mhz injection.  If that works, one could package a GPS
> disciplined PLL synthesized oscillator board directly into the XV144.  A
> board such as this is available from Steve Hicks, N5AC (and other sources).
> There are a number of approaches to minimizing PLL phase noise.  If you are
> interested in those references, let me know.
>
> Bill, W7QQ
>
>
>
> On Mon, Jul 1, 2013 at 4:21 PM, Carol F. Milazzo, KP4MD/W6 <
> kp4md at cfmilazzo.com> wrote:
>
>> I have achieved frequency stability to 1 Hz with the Flex-1500 & Elecraft
>> XV144 transverter combination, using a GPS disciplined OCXO on 116 MHz. I
>> have documented the XV144 frequency stability and drift data comparing the
>> GPS control against the stock crystal oven option with enhanced thermal
>> insulation here
>> https://picasaweb.google.com/114032640816757126398/XV144FrequencyStabilityModifications
>>
>> The stock FLEX-1500 TCXO is sufficient to hold the frequency to within 1
>> Hz. Enabling the 10 MHz sine wave external reference on the FLEX-1500
>> should increase the frequency accuracy and stability to the millihertz
>> range.
>>
>> Carol, KP4MD
>>
>>
>>
>>
>> *Bill Schwantes* bill4070 at gmail.com <elecraft%40mailman.qth.net?Subject=Re:%20%5BElecraft%5D%20XV%20Transverter%20Local%20Oscillator%20--%20GPSDO%3F&In-Reply-To=%3CCAFyNi86U3UyF%2Bu2eTUX0oG3pE%3D7zXb0VgjbijP8_xzgZGxXh%3DQ%40mail.gmail.com%3E>
>> *Thu Oct 20 00:57:06 EDT 2011*
>>
>>
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>>
>> ------------------------------
>>
>> Hi Guys and Gals,
>>
>> Does anyone know of a mod to the Elecraft XV transverters that provides for
>> 10 Mhz GPS disciplined oscillator control of the transverter local
>> oscillator?
>>
>> I think that would be a popular feature for Elecraft to consider on future
>> versions of XV transverters.  It would be similar to the K3EXREF Frequency
>> Lock Option for the K3, which works flawlessly.
>>
>> Bill, W7QQ
>>
>>
>