I also wish the oscillator could be replaced with an aftermarket unit, maybe
one like this:
http://www.greenrayindustries.com/library/yh1420.pdf
I don't know what those cost, but I would pay $200 to get better stability.
I know a lot of folks don't really care, but for ESSB, 10 Hz off frequency
starts to get noticeable. Besides, I just like being accurate!
Ron N6IE
www.N6IE.com
----- Original Message -----
From: "Martin Ewing AA6E" <aa6e@ewing.homedns.org>
To: "tentec-list" <tentec@contesting.com>
Sent: Tuesday, May 20, 2008 5:27 PM
Subject: Re: [TenTec] Orion 565 Oscillator frequency problem
> Rob / Jim,
>
> You could check my blog entries at
>
> http://blog.aa6e.net/2005/08/orion-frequency-calibration.html and
>
> http://blog.aa6e.net/2005/11/orion-recalibrated.html .
>
> The TCXO can be tweaked with difficulty so that it comes to equilibrium
> after warm-up a little closer to the correct frequency, but basically it
> is a +/- 3 ppm unit, and you can't tweak it much better than 0.5 ppm or
> so, and it won't stay set forever. Seasonal room temperature changes come
> into play at that level in my shack.
>
> Too bad the oscillator can't easily be replaced with a better one. You
> need one that is custom made for 44.55 MHz.
>
> 73 Martin AA6E
>
> K4CGY wrote:
>
> Hi Rob,
> Rig is within spec . Spec is ± 3 PPM which is 45 Hz @ 15Mhz
> and 60 Hz @ 20 Mhz. You have a maximum drift of 32 Hz @ 15 Mhz
> and 42 Hz at 20 Mhz. However the frequency starts off at 32 Hz
> low so if the TCXO has a trimmer it likely can be touched up a
> little to be closer.
>
> 73 Jim K4CGY
> --- Rob Santello <K6DQ@drumon.com> wrote:
>
>> Hello group,
>>
>> I've lately noticed my Orion 565 is way off frequency and
>> drifting
>> during warm-up. These measurements were taken at 80 degree room
>>
>> temperature beating against WWV on both 15 and 20 MHz.
>>
>> Initial turn on:
>> 15 MHz WWV: 14.999.968
>> 20 MHz WWV: 19.999.956
>>
>> 45 Minutes into warm-up:
>> 15 MHz WWV: 14.999.946
>> 20 MHz WWV: 19.999.928
>>
>>
>> 1hr 30 Minutes into warm-up:
>> 15 MHz WWV: 14.999.939
>> 20 MHz WWV: 19.999.919
>>
>> 3 hours into warm-up:
>> 15 MHz WWV: 14.999.936
>> 20 MHz WWV: 19.999.914
>>
>> So my questions are:
>> 1. Does it look like the TCXO has a problem or might it be
>> something else?
>> 2. Will adjusting the oscillator fix the frequency problem and
>> somehow positively affect the drifting as well?
>> 3. If the TCXO is bad, can the TCXO be replace at home or do I
>> need
>> to send it to Ten-Tec (and hopefully get any needed updates
>> too)
>>
>> Thanks for any help, suggestions and information.
>> --rob--
>> K6DQ
>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec@contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>
>>
>
>
>
>
>
>
> --
> Martin Ewing, AA6E
> aa6e@ewing.homedns.org
> +1-203-315-5160
>
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
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