Re: Affecting the use of digital modes... #qrm

Matthew Chambers NR0Q

But isn't JS8 a keyboard to keyboard mode, why couldn't it slide down to just below the FT8 allocation say to 14.073-14.074, it would fit in alongside PSK?
Matthew Chambers, CBT, NR0Q
M Chambers Communications Engineering LLC
PO BOX 855, Moberly, MO 65270
Mobile (660)415-5620

On Mon, Jun 1, 2020 at 8:19 PM Tom W7SUA <tom@...> wrote:
That will not work Matthew.

JS8 is active and occupies the space between FT8 and FT4.

73, tom w7sua

On 6/1/2020 11:11 AM, Matthew Chambers NR0Q via wrote:
> Personally I think they should have moved upwards rather than downwards
> as the x.070 to x.074 slice is still sometimes occupied by older
> narrowband digital modes such as PSK31 and it's variants and narrower
> versions of Olivia, along with MFSK. Why couldn't FT8 occupy x.074 to
> say x.078 with an overlap with FT4 from x.076 to x.078 and FT4 only up
> to x.080 for example. I recall that JT65 and JT9 had an overlap area
> with JT65 occupying the lower half and JT9 the upper half of the
> spectrum which worked well. A contiguous block of spectrum would make
> more sense for FT8/FT4 due to the nature of how those modes operate
> where we decode the whole swatch of spectrum at once. And with newer SDR
> technology, we could have a digital-USB bandpass that is 4-6 kHz wide vs
> the 2.8 kHz of most traditional radios, allowing us to see the whole
> FT8/FT4 suband at once. I'm not sure if the direction they were moving
> would allow for that contiguous block. As the number of digital modes is
> only going to continue to increase, finding ways for modes to share
> spectrum is going to need to become a higher priority.
> Matthew Chambers, CBT, NR0Q
> Owner/Engineer
> *M Chambers Communications Engineering LLC*
> PO BOX 855, Moberly, MO 65270
> Mobile (660)415-5620
> <>
> On Mon, Jun 1, 2020 at 6:21 AM Tomas, NW7US <nw7us.heliophile@...
> <mailto:nw7us.heliophile@...>> wrote:
>     Please see my two articles regarding an urgent issue involving all
>     digital modes on HF, including FT8 / FT4.
>     Part 1:
>     Part 2:
>     More parts to follow...
>     Be sure to read the comments left on each post, as there are great
>     points made in this discussion.
>     73 de Tomas, NW7US <> dit dit
>     +
>     + Space weather and radio propagation
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