[600MRG] SlowJT9 frequency limits

[Rik Strobbe]

Hi Andy,

the current upper frequency limits are 1400Hz for JT9-1 and JT9-2 and 840Hz for JT9-5.
The limits for JT9-1 and JT9-2 were set just to avoid unintentional  JT9 transmissions in the WSPR band (for 474.2kHz or 136.0kHz dial).
The JT9-5 limit os due to the resampling in combination with the 5kHz upper limit of the JT9 decoder.
Meanwhile I learned that on 136kHz several stations use a lower dial frequency to avoid the DCF39 QRM, so I intend to lift the current upper frequency limit of JT9-1 (will be 5000Hz then) and JT9-2 (will be 2250Hz due to the resampling) in the next release of SlowJT9.
Together with Markus, DF6NM, and Wolf, DL4YHF, I will try to find a way to allow higher frequencies (above 840 Hz) for JT9-5 and JT9-10 as well.
At this moment the lower frequency limit is 400Hz, but that will be lifted too.

73, Rik  ON7YD - OR7T

________________________________________
Van: Andy - KU4XR <ku4xr at yahoo.com>
Verzonden: zondag 30 december 2018 2:14
Aan: Rik Strobbe
Onderwerp: Maximum Audio Frequency for each Mode

Hi Rik:

I was not aware of a frequency limit for each mode.. Will you post to the lists the Maximum Audio Frequency
for each mode ? I think this will be useful information for other operators also.. Thanks for your work on SlowJT9..

73:
Andy - KU4XR