[Yaesu] RE:FSK/AFSK (Summary of Responses)

[Bill Brannick]

Sandy Lynch wrote:
> 
> I was kinda hoping to see the answer on the reflector.  Would
> you mind sharing your responses with me?  I had the same question
> as you.
> 
> 73, Sandy W7BX
> slay@netcom.com

I didn't save them Sandy.. but the bottom line is: 
(And I will will also copy this to the list, just in case someone thinks
I have misinterpreted anything)

If the FT-990 and Kam Plus are wired in accordance with the pin out data
provided by Kantronics... (I can share that info if you do not have it)
with just a single wire running to the RTTY  jack on the 990 (FSK) and
all other required paths going to the Packet jack...

RTTY/LSB puts you in  FSK with the shift (170, 425 or 850 Hz) determined
by the positioning of the dip switches 6 and 7 (Page 21 in my FT-990
manual). I use 170 Hz.

PKT/LSB will be AFSK (tones determined by SHIFT, MARK and SPACE
parameters in the KAM.  I use 2110/2310 with SHIFT set to MODEM. You
should also set dip switches 2 and 3 in the 990 to match these settings.
If you don't do this,  you will be unable to zero-beat or be "on
frequency" with the other guy. Also set the FSinv parameter in the Kam
Plus to ON.


IMPORTANT... I found that my 990 manual (circa 1991-92) had a  major
error in the Packet FSK Tone Pairs Table on Page 20. The settings of
switches 2 and 3 are reversed with respect to the 1070/1270 and
2110/2310 pairs.... to get 2110/2310 both switches 2 and 3 need to be
OFF!

There seems to be little difference in using FSK vs AFSK. No one has
suggested that it was better to use AFSK. I have been told that, if you
use more then minimal power (40 - 60 watts), there is less of a chance
of getting RFI into the audio lines of the TNC if you use FSK. I have
also heard that the FSK tones are "cleaner". Another outlook.. "purists"
say that Baudot and Amtor were designed for a 170 Hz shift and that 200
Hz is best for Packet and Pactor and Gtor. Well... you can't get a FSK
shift of 200 Hz out of the FT-990.. so if you want to be a "purist" I
guess you have to use AFSK to get the 200 Hz shift. I have been using
FSK  with a 170 HZ shift for the last 24 hrs in all modes and see no
problems whatsoever. I plan to continue using FSK exclusively, but I 
suspect that it does not make a huge difference either way..

Hope that helps.. let me know if you need the pin out info.. Kantronics
faxed it to me. They have data sheets for several different rigs.

Bill.. KN6FJ





> 
> >
> > As is almost always the case, I asked a question and almost immediately
> > got lots of knowlegable responses. Thanks to all who took the time to do
> > so.
> >
> > Bill

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