[RTTY] TS-570 Freq offset

[Dick Kriss, AA5VU]

Wolf,

You are correct.  I thought you were talking about AFSK.  When Kenwood
designed the TS-570, they assumed all RTTY would be run in FSK and operation
in AFSK for RTTY was not even a consideration.  The rig was designed before
sound card technology became popular.  When the TS-570 is in FSK mode, the
mark frequency is the displayed frequency.  For those of us that can only
transmit in AFSK, we operate RTTY in LSB and have to subtract 2125 Hz (if
using that tone) from the dial frequency to determine the mark frequency.

An  easy example is copying the W1AW RTTY bulletins that are broadcast in
AFSK to come out on the mark frequency of 14.095.00.  The TS-570 copies W1AW
at 14095.00 in FSK mode but if I put the rig in LSB for AFSK I have to tune
the dial display to 14097.125 or 14.095 MHz + 2125 Hz.

Since most RTTY operators 'tune-to-print' most of the time the offset is
only really important when spotting a station on the cluster or knowing
where to set your display to find a spot on the cluster.

Yes, I know modern (more expensive) rigs do the mark offset for you and some
software and logging programs also handle the offset.

73, Dick AA5VU


> Subject:  Re: [RTTY] TS-570 Freq Offset
> From:  "Wolf (DL6JZ)" <dl6jz at t-online.de>
> Date:  Wed, 11 Jan 2006 12:34:52 +0100
> List-post:  <mailto:rtty at contesting.com>
> 
> Sorry Dick,
> 
> my posting was not exact enough. The radio is able to correct the mark
> frequency offset only if you operate FSK (mode selector = RTTY)!!
> 
> 73 + 55
> Wolf, DL6JZ