[RTTY] FSK interface circuit troubles

[Kok Chen]

On Dec 10, 2008, at 12/10    6:43 AM, k0bx at arrl.net wrote:

> The kenwood TS-940 uses a reverse FSK from everyone else.

The FSK polarity in the Omni V and VI were "correct."  In their  
"normal" setting, the Yaesu transceivers I have used are also  
"reversed."   But the Yaesus have a way to change the transmit FSK  
polarity (a switch in the 990, a menu item in the 1000MP).

In this case, couldn't the polarity switch be done from the modem end  
instead of at the keying driver?  The software that I use has  
provision for reversing the FSK keying (although being an AFSK user,  
I've never had to actually use it).

73
Chen, W7AY