[RTTY] FSK is bad?

Thom ki8w at ki8w.com
Tue Oct 25 21:00:35 EDT 2016


You all are throwing so many good ideas around that I am starting to get 
confused.

> Unlikely. To the best of my knowledge, the only rig manufacturer who makes
> a serious attempt to reduce key clicks in FSK is Elecraft (and even then
> only after K0SM pointed the issue out). I hope someone like Chen or Andy
> who really knows (not someone just knee-jerk defending their rig because
> they have dropped a lot of money on it) will correct me if I am wrong.

well then I guess you are saying I spent money on the wrong rig. My rig 
is,  what it is.  I cannot change it.

>
>
>
> Your RTTY software should compensate for that. Any program that has CAT
> control of the radio so that it knows what the dial frequency is should be
> capable of subtracting the audio offset from the dial frequency and
> displaying and logging the correct Mark frequency. Most RTTY software has
> the ability to turn this offset calculation on (for LSB) or off (for FSK)
> as the user chooses. In MMTTY this setting is in the Radio command window
> under "Frequency offset". If you are running MMTTY under the control of a
> parent program like N1MM+, the setting will be in the parent program. In
> N1MM+ it's in the DI window's Setup menu - it's called AutoTRXOffset.
I have not seen anywhere to do that in Writelog or MMTTY.  Maybe you can 
enlighten me on how to do it.

Writelog has a "LSB is really FSK" selection but it does not change the 
radio frequency displayed in Writelog.

> The difference is not really in the transmitter, its in the receiver.
> For years I have used 1275/1445 because like Jeff says it sounds
> better. The RF transmitted signal is exactly the same, only the
> receiver is different.
>
> No, the offset frequency in FSK is set by the transmitter. MMTTY can only
> control the received frequency in FSK. Some transmitters allow you to
> choose different tone pairs for FSK via a radio menu option, in which case
> you can choose the one that sounds best to you. Regardless, you need to
> ensure that your software (receive) and your transceiver (transmit) agree
> on what tone pair you are using, otherwise your transmit and receive
> frequencies will be different.
>
>
Think I am going with 1275.  I like the sound better.  I have set my 480 
to that frequency.

73

Thom KI8W


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