[WriteLog] MMTTY and EXTFSK at 75 baud...

Robert Chudek - K0RC k0rc at citlink.net
Sat Jun 5 09:04:16 PDT 2010

This is a FYI message...

Operators planning to participate in the 75 Baud contests this weekend and next should be aware IF they are using the popular EXTFSK driver, this driver is hard coded to transmit at 45.45 Baud. Typically this driver is used to generate FSK & PTT keying (not AFSK) by RTTY software, MMTTY in particular.

Dave Bernstein, AA6YQ, verified this (documented) limitation. He maintains the MMTTY source code.

How do you know whether you are using the EXTFSK driver? Bring up your software configured for a RTTY contest. Look at the bottom of the screen to see if there is an EXTFSK 1.05 button displayed on the Windows task bar. If it is shown, you are using the driver and will only be able to transmit at 45.45 Baud.

There are many other RTTY packages that will allow 75 Baud TX speeds. If you were planning to participate in high speed RTTY, it would be a good time to investigate other options if you are currently using the EXTFSK driver.

73 de Bob - KØRC in MN

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