[WT-support] RTTY

[Rudolf Schwenger]

Good evening to the group,

Is there anybody out there who would be kind enough to help me to choose the correct settings for RTTY. I get lost trying to configure MMTTY, microKEYER/USB-Device Router, WinTest and the IC-7800 with the intent to copy and transmit clean FSK (not AFSK).

By far the best reception of FSK is by means of the built-in Decoder of the IC-7800. There is also no problem at all to transmit clean FSK by using the IC-7800 as a stand alone Radio with a keyboard connected to it. Although this setup works perfectly alright for random QSOs it is of course a hopeless proposition if one wants to take part in an RTTY contest: No auto-numbering, no logging, no comfort at all.

The best I could achieve so far - using the combination of WinTest V 3.14, USB Device Router V. 4.0.10, and an unknown version of MMTTY (app. 2 years old) - is the following

(a) RTTY-reception clearly worse than with the built in decoder of the IC-7800, i.e. I need stronger signals with less qrm/qrn to read a clear message

(b) if I press the F1-key for CQ for the first time, the radio seems to send the correct CQ-message. If I press it thereafter a second or third time I only hear diddles with an occasional burst of RTTY-info. The same is true for all other F-keys: First time they seem to perform ok, thereafter only diddles with occasional bursts of RTTY.

All of this has nothing to do with RFI: Even when outputting 5W only I still get the very same results.


Since I would like to participate at least for some hours in the forthcoming CQ WWDX RTTY contest I wonder whether there is anybody out there with a similar setup, who would be willing to share with me his MMTTY-, WinTest- and microKeyer/USB-Device-Router settings for perfect RTTY.

I know that I could deal with the subject by changing over to AFSK. That worked ok for me about a year ago - but only in very low qrm-level environments, i.e. not in contests. In other words I would like to make use of the excellent selectivity of the IC-7800 by using FSK rather than AFSK.

Thanks in advance for any help, which is much appreciated. 

vy 73 de Rudy, DJ3WE

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