Joe,

Thank you very much for your explanation.

I will ask detail analysis about available bandwidth to digital processing experts like you while developing the software including SDR program for this application.

Therefore, I will left the following comments as my inputs to your proposal.

1. As the congested JT65 HF bands in Japan, available spectrum is 42kHz at 20m (14.070-14.112MHz) and 70MHz at 40m (7.030-7.100). Therefore, I welcome you will pick up the bandwidth to match to Japanese spectrum allocation. This number has the magnificent impact for the negotiation with the regulators.

2. Your proposal will break the wall for SDR application program development. We will see $100 QRP SDR transceivers will dominate HF bands soon.

Regards,

take

de JA5AEA


*Re: [wsjt-devel] JT65 HF bands capacity, spectra allocation, and software support <https://sourceforge.net/p/wsjt/mailman/message/35684824/>*
From: Игорь Ч <c_igor@in...> - 2017-02-23 18:26:55
*Attachments:*Message as HTML <https://sourceforge.net/p/wsjt/mailman/attachment/1487873341.632950398%40f40.i.mail.ru/1/>
Hello Tsutsumi san and All,
.
Limitation is coming from sound card sampling rate:
.
48kHz -> 20kHz
96kHz -> 40kHz
192kHz -> 80kHz bandwidth.
.
We getting a bit less than 50% bandwidth of reliable data after the Fast 
Fourier transform.
.
73 Igor
.
>Re: [wsjt-devel] JT65 HF bands capacity, spectra allocation, and software 
support
>From: Takehiko Tsutsumi <take.tsutsumi@...> - 2017-02-23 12:19:36
>Attachments: Message as HTML
>
>Joe,
>
>Thank you for your quick response.
>
>I understood your basic approach.
>
>However, I have an impression that your indicated bandwidth 20kHz at initial 
stage and 80kHz as goal are humble and modest. This limitation would come from not 
only JT software but also come from RF receiver hardware. As you said you will 
assume it is SDR architecture, then, it can realize 48kHz with low-tier soundmodem 
based SDR such as SoftRock. If it is DUC/DDC type, 192kHz is a piece of cake to 
realize.
>
>If the bandwidth is 192KHz, it covers entire CW and RTTY chunk up to 12m band 
and we can negotiate incumbent at strong position from the beginning.
>
>Would you explain the reason why you pick up 20KHz number?
>
>Regards,
>
>take
>
>de JA5AEA


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