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Re: [TenTec] poor audio on OMNI-V

To: John Graves <jh.graves@verizon.net>
Subject: Re: [TenTec] poor audio on OMNI-V
From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
Reply-to: geraldj@storm.weather.net, Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sun, 29 Mar 2009 16:31:47 -0600
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
On Sun, 2009-03-29 at 18:12 -0400, John Graves wrote:
> 
> 
> Dr. Gerald N. Johnson wrote:
> > On Sun, 2009-03-29 at 16:36 -0400, John Graves wrote:
> >> If I may jump in with a question.  I have a jupiter but my Drake 2B rcvr 
> >> might need this, after I recap it.
> >>
> >> I have a MFJ 259B antenna tester, which will work as a frequency counter 
> >> that does resolve to 1 Hz.
> > 
> > Resolution is distinct from accuracy. What is the precision of the
> > counter's clock? It can be as bad as 100 ppm which is a 100 Hz error at
> > 1 MHz or 900 Hz at 9 MHz which is disastrous when aligning a BFO to a
> > filter.
> 
> Jerry,
> 
> The manual claims 1 ppm at room temperature.  It is an old (or at least 
> semi-old) MFJ piece of equipment.  But if it is 10 times worse than 
> spec, it sounds as though it is close enough to bring the adjustment in.
> > 
> John Graves
> WA1JG
> jh.graves@verizon.net

10 ppm at 9 MHz is 90 Hz. I thought the object of the task was to
resolve the difference between 200 and 300 Hz from the filter corner. A
potential error of 90 Hz is nearly all of that.

1 ppm takes care and annual calibration against a better standard. And
to do that at HF WWV takes a month of quiet propagation days to achieve
1 ppm.

73, Jerry, K0CQ

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