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[TenTec] High stability frequency reference oscillator for the Orion II

To: tentec@contesting.com
Subject: [TenTec] High stability frequency reference oscillator for the Orion II
From: Linwood Davis <linbdavis@earthlink.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 30 Dec 2009 22:16:55 -0500
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
Hello folks,

Primarily for the reason below, I've been considering drastically 
reducing the frequency drift over temperature that my Orion II 
experiences.  So I contacted Abracon Corp to see if they'll make a few 
44.55 MHz high stability oscillators to replace the original one with. 
I'm interested in the AOCJY  series oven controlled crystal oscillator, 
which has remarkable stability. Try 5 parts per billion stability! (over 
0 to 50C). That'd be three orders of magnitude better than the original! 
Anyway, I know they won't make just one for this mere hobbyist, but 
hopefully, they'll consider making 10.

So I'm here to see if any Orion owners would be interested in also 
purchasing one. I got a informal quote of $135 a piece so far.

Also, I don't know, but does the Orion (565) also use this frequency 
reference? Or any other Ten-Tec radio? I see from the O II schematic 
that the Sub Rx uses a divided-down signal from this same oscillator. If 
I remember right, the Sub Rx design is the same as the Jupiter Rx. 
(Please correct me if I'm wrong.) If so, are there any Jupiter owners 
that may be interested in joining this oscillator purchase?

So here's where the drift becomes annoying:

Recently, I begain "watching" meteors with my Orion II and DL4YHF's 
Spectrum Lab software. What I do, actually, is tune to 14.670 MHz (CHU 
Canada), and observe CHU's signal. Using Spectrum Lab's waterfall to 
display a 50 Hz swatch of spectrum around the carrier, I can see when 
micrometeors and not-so-micro meteors strike the ionosphere between 
here, NH, and there, Ottawa. Normally, the signal is fairly weak, so 
when a meteor ionizes a trail in between here and there, the signal 
strength significantly increases. What's more, the resulting spectrum is 
often composed of curves and lines above and/or below the carrier 
frequency. I believe these are created by the doppler shift due to 
ionospheric winds. (Why do I do this? Hey, I'm a curious guy, what else 
can I say?)

The trouble is, especially just after turning the Orion on (and for the 
next 30 to 45 minutes), the frequency drifts by as much as 10-15 hertz. 
Normally, you probably don't notice this, but when narrowed down to a 50 
Hz display, it looks bad! (See AA6E's site, 
blog.aa6e.net/2005_08_01_archive.html, or N6IE's site, www.N6IE.com, for 
addition drift info.)

Let me know,

Thanks,

Lin
WB1AIW

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