Topband: ARRL Board Requests Member Comments About Digital Modes

Mike Waters mikewate at
Mon Mar 3 19:37:57 EST 2014

Thank you. I forgot that in Region 1 (essentially Europe, Asia, & Africa),
160m starts at 1810.

Here's a couple of thoughts for discussion:
- Since two-thirds of the world --including North and South America--
starts at 1800, why not consider region-specific band plans? Is digital
popular in other places?
 - How about 1840 to ~1845 for digital in lieu of --or even in addition
to-- below 1810?

As for bandwidth, here's what K1JT says about the significant bandwidth
advantages of JT9 vs. JT65:
"JT65 was designed for EME ... in contrast, JT9 is optimized for HF and
lower frequencies.  JT9 is about 2 dB more sensitive than JT65A while using
less than 10% of the bandwidth. ... A 2 kHz slice of spectrum is
essentially full when occupied by ten JT65 signals.  As many as 100 JT9
signals can fit into the same space, without overlap."

73, Mike

On Mon, Mar 3, 2014 at 5:37 PM, Joe Subich, W4TV <lists at> wrote:

>  IMO, digital should go below 1810, AND it should preferably be a narrow
>> band mode such as the superior JT9 mode.
> Unfortunately, "below 1810" is never going to fly because of the lack of
> access below 1810 in many countries.  Further, JT65 although wider than JT9
> is certainly less than 200 Hz and should not be a concern to users of other
> narrow bandwidth modes. ...

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