John,
I think your group has done a fantastic job getting UK amateurs the
first general operating permits for 500K in Europe.
I'm interested in aerial experiments but, to make this offer some
returns on the effort, I would favour a power limit at the aerial input,
as we have on the higher bands. That way I will be motivated to make my
electrically small aerial as efficient as possible within its domestic
setting.
I don't really mind what that power limit is. Although 20W or more might
be nice for DXing, it doesn't seem necessary for inter-UK contacts. I
would be happy with 4 or 5W, which is what most people seem to be
running. Once other countries gain access to the band I think there will
be stronger case for higher power.
I'm a newcomer to the band, so treat these comments as "from a novice".
73,
Alan G3XAQ
In message <[email protected]>, John W Gould
<[email protected]> writes
Thought that I had better respond to Laurie's e-mail, now a few days ago.
This is because the matter of the power level is to an extent under
review by Ofcom. If you recall we, RSGB, asked back in 2004 for a 1W
ERP limit as that was consistent with experience at 136kHz. A ERP
limit also gives Ofcom a real view as to what the likely coverage would
be at any particular bandwidth. That we were offered -10dBW ERP
reflects both a bold step by Ofcom and also some caution, given that
they have to an extent taken an interesting view of ITU Radio
Regulation 5.58 to our benefit. RR 5.58 defines 500kHz as an
international distress and calling frequency for Morse radiotelegraphy.
Ofcom may have taken the decision as they may expect to be withdrawn at
WRC07, and on knowledge that in this part of the world 500kHz is no
longer used as an international distress calling frequency. Other
authorities have not been so minded, as Dick, PA0SE, recently
discovered; they prefer to wait until such time as RR 5.58 has been deleted.
Whilst we are currently limited to -10dBW RSGB/Ofcom are keeping the
matter under review and it may be timely, now that we have a good body
of experience to request that the limit be reconsidered. As far as I
am aware no interference complaints, or even local RFI problems have
been received, and our operating and conformance to licencing
conditions have been exemplary. From comments on this group it may be
better to request say a 10 or 20W power limit at the aerial feed-point,
for reasons mentioned by Laurie. Whatever change to the limit is
agreed, if indeed any in the near term, it will have to be a cautious
change until such time as the Radio Regulations are more helpful in
allowing administrations to consider proper secondary allocation to the
Amateur service. This may or may not happen for a while, as we are
only really working at present to get the matter firmly on the WRC2011
agenda, such is the speed of the ITU. There is good practical reason
for making a request of this nature as one of the reasons why the ITU
process seems so slow is that for normal protocol to be followed one
needs to have had technical studies completed that relate to the new
proposals for the part of the spectrum in question. Our activity
between 502 and 504kHz, along with that by the US, Germany and Sweden
may qualify as such a study, so continuing the experiments at a higher
power, with the added challenge of maximising ERP from a fixed
feed-point power limit would add some breadth to our work.
Of course, the unexpected could always happen, and we get something
sooner in the margins of Agenda Item 1.14 at this year's WRC. However,
as Agenda Item 1.14 is to review the operational procedures and
requirements for GMDSS and other related provisions our chances are
slim, as the Maritime service is likely to want to reuse the frequency
around 500kHz. However, it is an agenda item concerning this part of
the spectrum so the possibility, however distant, must be there.
I'd be interested in any further views to Laurie's proposal; I'am open
to suggestions as to the power level, but it will be important to hit a
target that is both challenging to the experimenter, helpful for
continued propagation research and also one that will not provide too
much risk for Ofcom in terms of coordination with the primary user service.
73 John, G3WKL
RSGB HF Manager
IARU Region 1 LF Coordinator
--
Cheers,
Alan G3XAQ
[email protected]
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