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

Robert Chudek - K0RC k0rc at citlink.net
Sun Jun 6 13:09:40 PDT 2010

Glenn, et. al.,

You are correct. Using the AFSK mode of MMTTY will work just fine. The 45.45 
Baud TX limitation is not within the MMTTY program itself. The limitation is 
imposed IF you are using the EXTFSK driver. Some operators use EXTFSK while 
many others do not. So "it depends" and this was the reason for my alert to 
check your configuration before the contest.

Because the 45.45 Baud rate has been considered the "amateur radio standard" 
(totally discounting the fact that some Model 15 Teletype operators had and 
used alternate gear sets to run at 75 Baud), not much consideration was 
given to providing a mechanism to change TX speeds from the "standard".

I'm kind of excited about the "EXTFSK discovery" because this forced me to 
rethink my own station setup. I am looking at many options in order to get 
ready for some BARTG SPRINT 75 fun next weekend.

Don Hill and Joe Subic worked through the steps of getting WriteLog running. 
You can visit Don's new setup page here: 

For N1MM Logger users, MMTTY can be used in AFSK mode at higher speeds. 
Also, the MMVARI and FLDIGI engines are options within N1MM Logger that you 
can use.

A standalone version of MMTTY can be used in AFSK mode. It can also be used 
when it is directly driving a COM port in FSK mode. The COM/FSK solution is 
typically limited to older computers running Windows 98 or older.

If you have a DOS machine, the original RTTY contesting program "RTTY by 
WF1B" is an option as well as the high performance "RITTY" program by K6STI.

Many of the AEA, Kantronics, MFJ, and HAL hardware decoders can RX/TX higher 

"It would be nice" if the EXTFSK.DLL would be updated to provide higher FSK 
TX speeds. But with all the alternate methods of generating 75 Baud RTTY, it 
is not likely to be a high priority item.

One thing is for certain, getting your station ready to operate at 75 Baud 
RTTY will challenge your "status quo" status!

73 de Bob - KØRC in MN

----- Original Message ----- 
From: "Glenn Anderson" <wb5tuf at earthlink.net>
To: "'James Colville'" <jimw7ry at gmail.com>; "'Robert Chudek - K0RC'" 
<k0rc at citlink.net>
Cc: <N1MMLogger at yahoogroups.com>; <rtty at contesting.com>; 
<cq-contest at contesting.com>; <writelog at contesting.com>; 
<MMTTY at yahoogroups.com>
Sent: Sunday, June 06, 2010 8:28 AM
Subject: Re: [CQ-Contest] [RTTY] MMTTY and EXTFSK at 75 baud...

I plan to use AFSK. It should work just fine.

Glenn WB5TUF

-----Original Message-----
From: rtty-bounces at contesting.com [mailto:rtty-bounces at contesting.com] On
Behalf Of James Colville
Sent: Saturday, June 05, 2010 8:30 PM
To: Robert Chudek - K0RC
Cc: N1MMLogger at yahoogroups.com; MMTTY at yahoogroups.com;
cq-contest at contesting.com; writelog at contesting.com; rtty at contesting.com
Subject: Re: [RTTY] MMTTY and EXTFSK at 75 baud...

Sounds like the contest is a bust then.... If MMTTY wont work.

MMTTY is the most used RTTY program.

Jim W7RY

On Sat, Jun 5, 2010 at 9:04 AM, Robert Chudek - K0RC
<k0rc at citlink.net>wrote:

> 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
> see if there is an EXTFSK 1.05 button displayed on the Windows task bar.
> 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
> to investigate other options if you are currently using the EXTFSK driver.
> 73 de Bob - KØRC in MN
> _______________________________________________
> RTTY mailing list
> RTTY at contesting.com
> http://lists.contesting.com/mailman/listinfo/rtty

Jim W7RY
RTTY mailing list
RTTY at contesting.com

CQ-Contest mailing list
CQ-Contest at contesting.com

More information about the WriteLog mailing list