From: "Dave Sergeant" <dave@davesergeant.com>
To: rsgb_lf_group@blacksheep.org
Date: Thu, 06 May 2010 07:00:07 +0100
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Subject: LF: =?UTF-8?Q?Re:_500_Permit_emission=E2=80=99s_bandwidth=3F__EU_and_Global_=3F=3F?=
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On 5 May 2010 at 22:39, Graham wrote:


> Can any one indicated  what is the  permitted  ~telegraphyTM  bandwidth=
=20
> of the various ~newTM 500KHz  licences or  special  permits issued round
> the  EU and now the  rest of the  Globe ?=20
>=20
> 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 ?. =20
>=20
> Norway  is CW only  ? what is the  Dutch  allocation ? Southern Ireland
> ? ... etc=20

> Are  Beacons defined by  mode or  bandwidth  ?

It is important to differentiate between 'permitted' as a licence=20
requirement or 'actual' bandwidth. The UK has never had bandwidth (for=20
any mode) specified in its licence for any band, only a general note=20
(note (a) on p. 14) that it should be the minimum that the technology=20
and nature of transmission permit. My 500kHz NOV says nothing=20
whatsoever about bandwidth (only spurious emissions), and for what it=20
is worth at my request is for CW (A1A) only, ie no data. Norway I think=20
is the only country with a permit that does stipulate 100Hz as a=20
licence condition.

100Hz may be the 'actual' bandwidth of a typical CW signal at normal=20
speeds - though will be higher at >60wpm or so, which I have not yet=20
heard on 500kHz. The IARU Region 1 bandplans stipulate that the=20
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=20
be using 300-400Hz filters, occasionally going to 100-200Hz to=20
eliminate QRM problems. Much has been said about the very narrow=20
bandwidth of some of the data modes, but this is largely irrelevant to=20
the CW op who will still be using much wider filters. A point to be=20
taken into account when deciding which parts of the bands to put CW and=20
data (on any band, not just 136/500).

73 Dave G3YMC

http://www.davesergeant.com