[RTTY] Icom FSK interface

[iw1ayd - Salvatore Irato]

As the last kid of the block, may I suggest to add two potentiometers, 
easy to be reached and used, on any home made interface. I have done 
this several times, before to switch over ready made boxes. But I still 
like and use commercial boxes only with the same feature. One knob is 
for the AUDIO IN and the second is for the AUDIO OUT. This second one 
will be useful for other digital, hiss and whistle, modes, not for RTTY 
when FSK is in use. Don't care of the second one for FSK. use it for 
JT65, WSPR and other exotics modulations.
Adding those levels control, IMHO, is really useful. As levels, bot IN 
and OUT, changes for any different programs used to hiss or whistle into 
any radio and to receive the same noisy signal, are much more easy 
managed via two external analog controls than with the "digital" 
controls inside the any PC. That's for some different factors. Leaving 
out that usually those PC level control just strip some bit to decrease 
the output levels. For our purposes and ours maxed out 2.X KHz bandpass, 
this isn't a real problem.

Simply, having and using by hands, the two level knobs, RX and TX, will 
help a lot when changing programs, modes and even radios for the luckiest.

    CU all on air, next weekend.

               73 de iw1ayd Salvo