[GreenKeys] Hoffnet crystal source

[Roy Morgan]

At 03:09 PM 11/9/2004, Russmill47 at aol.com wrote:
>  ...
>I did check and found that I still have my original crystal from the
>original "Hoffnet" on 20M.  I think the original autostart net frequency  was
>14075.00 KHz.
>
>What is the new net frequency?  I'd like to order a crystal for that
>frequency as well.

Russ, and all,

Bry Carling has been selling (presumably new) FT-243 crystals, and may have 
or be able to get a batch of them for our Hoffnet frequency.  Here is his 
recent post:

>From: "Brian Carling" <bcarling at cfl.rr.com>
>To: baswaplist at foothill.net
>Date: Wed, 10 Nov 2004 05:52:16 -0500
>Subject: FOR SALE: FT243 Crystals
>
>FOR SALE: FT243 crystals as follows:
>160m CW and AM:
>1815, 1822, 1825, 1850, 1885, 1900, 1930, 1945, 1970, 1985
>kHz
>
>80m CW:
>3510, 3520, 3528, 3530, 3535, 3540, 3548, 3558, 3560, 3573,
>3577, 3579 kHz 3606, 3610, 3622, 3615, 3643, 3686, 3700,
>3702, 3703, 3705, 3712, 3715 kHz
>3721 kHz
>
>75m AM:
>3837, 3855, 3870, 3875, 3880, 3885, 3890 kHz.
>
>40m CW:
>7000, 7014, 7015, 7018, 7028, 7030, 7032, 7035, 7037, 7040,
>7043 kHz
>7044, 7045 7047, 7050, 7052.7, 7058, 7065, 7073, 7075,
>7100, 7123, 7143, 7146 kHz
>7150 kHz
>
>40m AM:
>7175, 7159(S), 7200, 7225, 7250, 7252.5, 7255, 7260 kHz
>7273, 7275, 7280, 7285, 7290, 7293, 7295, 7300 kHz
>
>30m and 20m AM and CW Fundies:
>10106, 10108, 10112, 10120, 14060, 14150(S), 14286 kHz
>
>These are all $9.00 each plus shipping.
>
>I have a few other Ham Band HC6U and FT171 and DC34 crystals
>plus a bunch of oddball frequencies.
>
>http://www.af4k.com/crystals.htm


Note that your transmission/crystal frequency may well depend on the mode 
of TTY generation you use:
- AFSK fed to a SSB transmitter needs the proper offset.
- Schemes such as used by TMC and Northern Radio need a fundamental crystal 
that multiplies up but is offset from the fundamental by a mysterious 
amount (often 200kc.)

I'd be interested in hearing how other folks managed this in the past, and 
also some comments on the designation of the frequency:
  - Is the specified frequency the center of the mark-space shift 
transmitted signal?
  - or is it the mark frequency?
  - or is it the non-present "carrier" offset by the 2050 cps or whatever?

Roy


- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
7130 Panorama Drive, Derwood MD 20855
Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
roy.morgan at nist.gov --