Re: [wsjt-devel] WSJT-X: Working frequency suggestions

[Bill S. <g4...@cl...>]

On 06/07/2017 09:14, Takehiko Tsutsumi wrote:
> Finally, it is a great idea to allocate "JT9 on same frequency as 
> JT65" on 2200m and 630m. I really wish you to expand this idea up to 
> 6m band as it is a first step to obsolete JT65 and replace to JT9 
> today and FT8 later.  It is the time to deploy this transition to 
> encourage newly developed frequency spectrum efficient code usage by 
> the recent rapid increase of the traffic. I do not think we will see 
> the side effects sharing the spectrum between JT65 and JT9. Am I right?

HI Take san,

thanks for your other comments, that is helpful as we have little 
experience or data modes usage in region 3.

There is a down side to sharing JT9 and JT65 allocations, the JT9 
decoder gets confused by JT65 signals and has to spend a lot of time 
trying to synchronize them as one or more JT9 signals. This detracts 
from the JT9 decoding turnaround. This is why the dual mode JT9+JT65 
decoder expects to decode JT9 signals above the blue separator line. If 
you move that separator down to zero on a band full of JT65 signals you 
will probably see the problem.

73
Bill
G4WJS.