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Unfortunately, the old people who run the system still mandate CW idents. I see no point whatsoever in them, but whatevs...
The period of plain carrier, also mandated, is essential as it gives a constant measure for any beacon.
But the proper modulation type is a free-for-all. So a combination of fast mode plus slow mode is quite possible. JT9 woul dbe good for that as it can have a lot of generator code in common, just changing the symbol rate and tone shift . In fact for uWaves, the same tone shift for fast and slow mode could even be maintained.
On Wed, 22 Jan 2020 at 17:25, Neil Smith G4DBN <neil@...
Something like the sound of a pump key with a CO/PA two-valve
transmitter circa 1956 would do the job. Decent click, bit of
droop, gradual drift, good amount of chirp, and a few character
spacing and symbol length errors to add some idiosyncratic
"swing". Instant recognition of the "fist" without hearing more
than a couple of characters.
Is a CWID actually required at all under the beacon licence? The
beacon could have a theme tune instead. Local folk song melody,
or a nice short ID like the Radio Tirana ident from the 70s.
I'd certainly be keen to have a decent slow mode like JT4F/G or
PI4 which would work via rainscatter as well as weak troposcatter,
but also a fast mode like JT9F-fast that would work off aircraft,
and some plain carrier to look at the shape of the troposcatter
spectrum over 20s or so.
On 22/01/2020 17:09, Andy G4JNT wrote:
you're saying, for the olde-mann ident stage, it would be
preferable to introduce a carefully designed, non-linear chirp
along with a bit of PR noise. That can be done with a PIC /
DDS combination, so a direct upconversion based beacon
should be able to manage it. But a PLL or RDDS based one
can't hack it
the use the CW ident is, might as well do something special
and use some artistry for its sound.
there's a thought for any GB3SC# update - a custom CW ident
On Wed, 22 Jan 2020 at 17:01,
Neil Smith G4DBN <neil@...
It is a GLORIOUS sound Adrian, expecially after it has
travelled 342km to reach here, which, as you know, it does
quite often. I like PI7RTD as well, and all of the others
the whoop and slide and chirp. Perfection is boring, at
least for the CWID.
On 22/01/2020 15:56, Adrian G4UVZ via Groups.Io wrote:
Whilst the idea of keying the 5Mhz
sounds interesting ..I fear that the df/dt of the keying
by the time it had gone through the PLL would be pretty
poor..as you can hear the exisiting keying is no