Ok Dave,
Yes , My Permit is the same , with all modes except speech, there
is a possibility that after the Ros tests in the week, that Jose ,
may code a faster version of the eme mode as a live chat mode, but I
have advised him that there is a problem with the mode bandwidth, so
any system coded may have to fit into a 100 Hz slot.
There are other issues which are well aired , however assuming at some
point these are resolved, then it should prove to be a viable data
mode for 500 and possibly 137 (assuming 100 Hz is ok on 137) He has
indicated , quote ' 100 HZ at 6.25 baud. Speed it would be about 150
characters/minute, half of PSK31, and 8.5dB better than PSK31.' this I'm
sure would be most useful and being single carrier /phase-c is suited
to the E/D pa's in use and would not suffer from the phase problems
on 500 that psk has.
Lets hope this is a positive outcome from the Ros tests last week !
G ..
--------------------------------------------------
From: "Dave Sergeant" <[email protected]>
Sent: Thursday, May 06, 2010 7:00 AM
To: <[email protected]>
Subject: LF: Re: 500 Permit emission’s bandwidth? EU and Global ??
On 5 May 2010 at 22:39, Graham wrote:
Can any one indicated what is the permitted ~telegraphyTM bandwidth
of the various ~newTM 500KHz licences or special permits issued round
the EU and now the rest of the Globe ?
I have the impression that 100 Hz is the maximum ~telegraphyTM
transmission bandwidth, in some cases, eg , Belgium at 100 Hz . Others
appear to be some what wider or not defined ?.
Norway is CW only ? what is the Dutch allocation ? Southern Ireland
? ... etc
Are Beacons defined by mode or bandwidth ?
It is important to differentiate between 'permitted' as a licence
requirement or 'actual' bandwidth. The UK has never had bandwidth (for
any mode) specified in its licence for any band, only a general note
(note (a) on p. 14) that it should be the minimum that the technology
and nature of transmission permit. My 500kHz NOV says nothing
whatsoever about bandwidth (only spurious emissions), and for what it
is worth at my request is for CW (A1A) only, ie no data. Norway I think
is the only country with a permit that does stipulate 100Hz as a
licence condition.
100Hz may be the 'actual' bandwidth of a typical CW signal at normal
speeds - though will be higher at >60wpm or so, which I have not yet
heard on 500kHz. The IARU Region 1 bandplans stipulate that the
telegraphy only parts of the bands have a bandwidth of under 200Hz.
Also needs to be considered is the receiver bandwidth. Most CW ops will
be using 300-400Hz filters, occasionally going to 100-200Hz to
eliminate QRM problems. Much has been said about the very narrow
bandwidth of some of the data modes, but this is largely irrelevant to
the CW op who will still be using much wider filters. A point to be
taken into account when deciding which parts of the bands to put CW and
data (on any band, not just 136/500).
73 Dave G3YMC
http://www.davesergeant.com
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