[SCCC] NAQP RTTY This Saturday - SCCC Teams

[John Rotondi, W6JBR]

Hello Ryan,

I see that you have recommendations for a logger such as N1MM+, which I also highly recommend. However, I think that you may have been asking about a RTTY modem program? 

Besides N1MM+, you will need an RTTY modem app. Several can be integrated within N1MM+, including the general digital modes app FLDIGI, and the RTTY-specific MMTTY. I recommend installing both, and interfacing them within N1MM+.
I do strongly recommend using MMTTY for RTTY.

Note that there are two variants of RTTY transmissions:
Historically, RTTY has been accomplished by the use of Frequency Shift Keying (FSK), which is a CW signal shifted between two frequencies to create a Mark and Space, at a specific rate. The standard amateur RTTY shift is 170 Hz, with 850 Hz used by military, and in some other applications. The standard amateur baud rate is 45.45 baud.

With the use of computers, modern transceivers accomplish transmitting Mark and Space tones using soundcard audio modulation transmissions in Lower Side Band (LSB) mode. This variant of RTTY transmission is Audio Frequency Shift Keying (AFSK).
The receiving station generally cannot tell the difference between the two, unless the AFSK signals are over modulated- which of course cannot occur with FSK, being a shifted CW signal.

So, AFSK is probably easier to accomplish if you have been operating any other soundcard modes. However, the setup requiring audio I/O levels, and possible modulation frequency offsets, makes FSK more reliable and easier to set up, IMHO.

If your rig has an FSK Keying Input, this, coupled with a PTT signal, can allow you to do FSK. You will need to provide a simple hardware interface from the computer to provide these two signals. An additional software module may need to be added to MMTTY in this case. OR, you can use the second set of outputs from a Winkeyer3 USB keyer using firmware v3.1 to generate FSK and PTT, alleviating the need for any interface hardware or additional software modules. I operate RTTY in this fashion using my Winkeyer3 USB.

I hope this information is helpful. 

Good luck in the contest!

73 de John, W6JBR


de W6JBR’s iPad
_..  .    ._ _   _ ....  ._ _ _   _...  ._.

> On Jul 17, 2024, at 12:40 PM, Ryan Huggins via SCCC <sccc at contesting.com> wrote:
> 
> I have not done RTTY yet, but it's been on my to-do list.  What software do you recommend for it?
> 
> 
> -73
> Ryan, KI6BTY
> 
> 
>> On Wednesday, July 17th, 2024 at 10:03 AM, Dennis Younker NE6I <NE6I at cox.net> wrote:
>> 
>> Hi all,
>> 
>> If you'd like to on an SCCC team for this Saturday's NAQP RTTY contest,
>> please let me know. So far, we have:
>> K6MUG
>> KF6RY (W6ZL)
>> 
>> 73, Dennis NE6I
>> 
>> -----Original Message-----
>> From: SCCC sccc-bounces at contesting.com On Behalf Of Dennis Younker NE6I
>> 
>> Sent: Monday, July 15, 2024 2:44 PM
>> To: sccc at contesting.com
>> Subject: [SCCC] NAQP RTTY This Saturday - SCCC Teams
>> 
>> Hello all,
>> 
>> The July edition of the NAQP RTTY contest is this Saturday. If you'd like to
>> be on an SCCC team, please let me know.
>> 
>> 73, Dennis NE6I
>> 
>> 
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> 
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