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Message-ID: <003701c6a6cf$ad7e1440$0300a8c0@lark>
From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
References: <001901c6a6cc$bf0801b0$6501a8c0@eagles>
Date: Thu, 13 Jul 2006 23:57:07 +0100
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Subject: LF: Re: DFCW TS450  FSK shift adjustment   HELP?
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Status: O

Hi J, Is it stable enough for that ??
Even at 60 sec dots you dont need go so low. 1Hz shift is quite readable if
you are not bothered about fitting into a narrow slot. I dont know the
TS-450 but I think the FSK may be produced by adding DC keying to the PLL
Loop so it may be a soldering iron mod. If it is, one thing to watch is that
you dont want to be conveying small keying signals (for a small shift) over
long lengths of wire. So put a potential divider right at the addition point
in the PLL loop and feed a bigger DC shift to it for keying. That will give
you a better noise margin.

Cheers de Alan G3NYK

----- Original Message -----
From: J. Allen <vy1ja@northwestel.net>
To: LF (RSGB) <rsgb_lf_group@blacksheep.org>; <lowfer@lwca.org>; Scott
Tilley <sthed475@telus.net>; Steve McDonald <jsm@gulfislands.com>;
<nccc-announce@kkn.net>
Sent: 13 July 2006 23:36
Subject: LF: DFCW TS450 FSK shift adjustment HELP?


> To All my Friends,
>
> Does anyone have a TS450 service manual and know how to explain how to
> modify or adjust the FSK shift down to10 Hz. on the 450?  Ideally, the
> change should be reversible.
>
> To speed communications in the VY1JA 137 kHz experiment with the low level
> of received signal in the south, DFCW will be essential.  The TS450 has
FSK
> provision with a minimum of170 Hz. shift. Since the frequency is divided
by
> 100, the shift must be reduced to 10 Hz., so that the DFCW has a 0.1 Hz.
> shift after division.
>
> For my friends in NCCC,  I know this message does not relate to
contesting,
> but I was hoping to find someone, somewhere who would help and it would
> greatly help if the change could be completed as soon as possible.
>
> Help?
>
> Thanks,
>
> J. Parke Allen,   "J." (given name)
> VY1JA,             "JA"(sign)
>
>
>
>
>