[RTTY] Self spotting question

Phil Sussman psussman at pactor.com
Tue Jul 12 08:43:20 PDT 2011


When an AFSK signal is properly adjusted it is not possible to determine
whether the signal was generated by using AFSK or FSK. The probability of
mis-adjustment, of course, is far greater with AFSK than with FSK and that
contributes to the myth that AFSK is inferior to FSK.

Other advanced modulation schemes, (eg. Pactor, Clover, PSK-31, etc.) do
require modulating the rig. My contention is that we ought to be educating
the proper adjustment of rigs rather than bemoaning the quite frequent
misadjustment of same.

The complaints of poor (overdriven) adjustment are not limited to digital
modes.

I believe in the 50% rule, where a 100w rig will operate best when
properly adjusted and operated at 50w (50% of rated power). In addition,
the duty cycle is reduced and the life of the equipment is extended.

The use of linear amplifiers on digital modes is overkill to me. If one
fellow decides to run RTTY with 1500watts then others complain that it
forces everyone to run power as well. One thing for sure, nothing
amplifies an overdriven signal (and creates a worse situation) other than
a full power output liner. Heavens to burnout, eh?

73 de Phil - N8PS

-----

Quoting Tom Osborne <w7why at frontier.com>:

> AFSK is probably OK for the newer radios, but for the older ones like my old
> TS-450SAT's, I need FSK so I can use the CW filters.  Otherwise I'm running
> RTTY in the 2400 cycle bandwidth.  73
> Tom W7WHY
>
>
> One of the questions that this brings up is -
>
> Is FSK still the dominate or do the Majority of RTTY users use AFSK?
>
> With Programs like FLDIGI where you use USB for everything becoming the
> norm?
>
> Dave Greig
> N3BUO



More information about the RTTY mailing list