[Elecraft] K3 DATA A vs USB for JT65/JT9

[Joe Subich, W4TV]

On 2015-03-17 12:41 PM, Fred Jensen wrote:
 > Can you 'splain the difference between AFSK and DATA A?

AFSK A and DATA A are both audio modes.  AFSK A uses LSB
and FC is set to MARK - 85 Hz (the center of the two RTTY
Tones).  DATA A is USB and FC is set to 1500 Hz (the center
of the transmit audio passband [200 - 2800 Hz]).

AFSK A also allows use of the AFSK transmit filter (a tight
filter around the Mark/Space tones to eliminate hum/pops/etc.)
and the use of the Dual Tone filter on receive.

73,

   ... Joe, W4TV