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


Hi Matthew,

I do not think of JS8 as a normal keyboard to keyboard mode like psk31 or Olivia. There is rather a community of users that use the features of the JS8Call program. The program uses a derivative combination of the WSJT-X FT8 modem and the chatting, relay and messaging features of the FSQCall program. Has robustness of the FT8 modem and multiple decoding but also has multiple speeds that let you trade speed and width versus robustness, program decodes all the speeds at the same time, allows you to relay via intermediate stations that are left on to provide a service, lets you issue a "heartbeat" to see whose station can hear you, and so on. You have a common USB dial frequency then many narrow band stations chat in the 2-3KHz above that dial frequency. Sometimes joining in ad hoc nets.

PSKreporter's map includes JS8 and most JS8 users do spot other stations.

I take it you have not tried JS8? Please go to and read the documents then download the program. Just like WSJT-X you pick a band and the program tunes to the common dial frequency for that band. Also has several other features like relay and messaging.

Would be incompatible I think trying to put the JS8 watering hole where psk31 and Olivia et al stations are expecting to find space for operating. Thus the chosen area where the WSKT-X users had mostly left.

73, tom w7sua

On 6/1/2020 6:33 PM, Matthew Chambers NR0Q via wrote:
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 < <>> 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
> 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
> 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
> 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
> 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
< <>
> <
<>>> 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
>     points made in this discussion.
>     73 de Tomas, NW7US <> dit dit
>     +
>     + Space weather and radio propagation
>     <> editor for CQ Amateur Radio Magazine
>     <>, and The Spectrum Monitor
>     <> magazine.
>     + YouTube: <>
>     + Social Media:
>          - Twitter: @NW7US <> =
>          - Facebook (As NW7US):
>          - Facebook (As Space Weather and Radio Propagation Page):
>          - Blog:
>     ..

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