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Date: Thu, 19 Jul 2007 10:22:01 +0100 (BST)
From: John GM4SLV <gm4slv@sighthound.demon.co.uk>
To: rsgb <rsgb_lf_group@blacksheep.org>
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Subject: Re: LF: 500 v 136
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On Wed, 18 Jul 2007, hamilton mal wrote:

> Hi All
> It looks like 500 is going the same way as 136. If Beacons and QRS are the
> trend then the band will fizzle out when the novelty wears off.
> QRS does little to encourage improving antennas or more efficient PA
> systems, or perfecting the basic skill of using CW, which has always been
> the traditional mode on the band.
> G3KEV

Unfortunately I think the ERP restriction on 100mW may be what drives 
the use of QRSS modes. Certainly from this QTH a lot of the active 
stations are over 900km away and QRSS gives much more chance of getting 
a contact, albeit not a "real one".

If we stick the the letter of the law then there is little to be gained 
from improving antenna efficiency since that then requires a 
commensurate reduction in transmitter power to maintain the ERP within 
the limit and nothing is gained except (for single antenna 
working) that RX performance may improve, although that's often limited 
by external band noise anyway.

PA efficiency is also a moot point when just about anything up to 20w RF 
can generate 100mW ERP form even the simplest MF antenna and even at 50% 
efficiency we aren't going to worry about dissipation in the PA at that 
power.

I do agree that perfecting the skill in CW is a help to operating, 
especially at low S/N ratios that we have with the low ERP. I can't 
speak for the stations who are clumped together in the SE of England, 
where seemingly S7-9 signals are regularly received, by up here I've 
never heard a CW signal that has been stronger than RST 339 (and that's 
not sn S-Meter 3, it's a real S3 in the old money - no S-meter 
deflections have been seen on any signals) so it does make you try 
harder to read CW under weak signal conditions.

Another aspect that seems to drive the beacon/QRSS is the low number of 
active stations and therefore low probability of any of them being 
active at the same time. We all have other calls on our time. Perhaps 
some form of "Inverse Silent Period" is needed to try and clump together 
the activity.

At least if someone has a beacon transmission running it's a chance to 
receive reports and for there to be a visible presence on the band for 
anyone new (like me) coming into the LF/MF world for the first time. 
Better to hear a beacon and think "gosh I've heard something on 500, 
let's get involved" than to think "I can't hear anything, is it because 
my set-up doesn't work or becuase there's no-one on the band?"

I've had some correspondance this week with Brian GM4JYB who is on 
Dunnet Head in the far north of Scotland and has been able to copy 
Finbar's beacon and as such is interested in going further, time 
permitted.

I think what I'm trying to say is that any RF radiated on 500 has to be 
beneficial, but hopefully the intention will always be to get on the key 
for real QSOs when possible.

Just my thoughts while I wait for OFCOM...

Cheers,

John


-- 
G-GRP-Club 2377, QRP-ARCI 12384, SKCC 3214
Member : RSGB, ARRL
Shetland Islands (EU-012) IP90GG
Lerwick Radio Club : http://www.gm3zet.org