AA6YQ comments below.
-Original Message-
From: digitalradio@yahoogroups.com [mailto:digitalra...@yahoogroups.com]on
Behalf Of AC TALBOT
Sent: Tuesday, August 03, 2010 5:46 AM
To: digitalradio@yahoogroups.com
Subject: [digitalradio] Direct RTTY Generation
A back-to-basics question for once...
Is there any modern RTTY datacomms software that gives a single wire digital
output for driving an FSK transmitter? Looked in the MultiPSK and MMTTY
setup menus and nothing.
MMTTY provides this FSK signal via the TxD pin of the serial port
specified in the PTT FSK panel on the Setup MMTTY window's TX tab.
Since using this signal requires a serial port capable of 45 baud operation,
which some USB-to-serial-port-adaptors can't do, you can set the PTT FSK
panel's port selector to EXTFSK, which displays a window that lets you
configure the generation of an FSK signal on a serial port's RTS or DTR
pins. In this latter configuration, the timing of the FSK signal is
software-generated, and thus less accurate than that generated by a 45 baud
serial port.
Digital mode applications that use MMTTY as their RTTY Engine --
WinWarbler, HamScope, etc. -- thus offer this capability.
While I realise there may be little call for such a one-wire drive now
Not true! Modern transceivers provide RX filtering for RTTY that is only
availalble when the transceiver is operated in RTTY mode, thus requiring the
FSK signal when transmitting. Icom's ic-7200, ic-7600, ic-7700, and
ic-7800 all provide a very nice twin-peak filter that is only available in
RTTY mode.
73,
Dave, AA6YQ
