[UK-CONTEST] Antennas

[Ray James]

--- On Sun, 8/5/11, Ray Hills <g3hrh at btinternet.com> wrote:

> Rather OT but we need some
> advice.  The group responsible for the GB3MCB 
> beacons in Cornwall is looking to replace the antennas (6,
> 4, 2 and 70) 
> which have been up for a long time.  The site is very
> exposed so physical 
> ruggedness is the main consideration.  Any
> recommendations would be welcome.
> 
> Ray G3HRH 


Hi Ray,
Your group are very fortunate with that substantial tower.
Possibly too large for 6m/4m but a flat panel/dopple quad for 2m and 70cm sealed into a rectangular enclosure has numerous advantages.

1. Gain
2. Wide Beamwidth for improved UK coverage
3. Antenna completely protected from the elements
4. Enclosure can have multiple rear mounted anchor points on your mast to offset any additional wind loading.

I was actually hoping 23cm might have been included in that list as the current antenna (15/15el) beamwidth is very narrow which is a limiting factor for the beacons wider UK reception possibilities though I appreciate it has been heard under exceptional lift conditions well over 1,300km away. Unfortunately, such openings are rare and therefore 99% of the time it is UK based reception that matters.
As an example, our local 23cm/13cm GB3CSB beacons both use flat panel antennas with a beamwidth of 67 degrees and therefore provide the potential for coverage throughout all of southern Scotland, the whole of England and Wales and under lift conditions all of northern France and Germany plus the whole of Holland and Belgium.

Hope that helps.

73 Ray GM4CXM

For those interested in reviewing all European beacons from 6m through to microwaves, the beacon and reception details including bearing and distance for registered uses, the UK Microwave Group provide a superb facility at http://www.beaconspot.eu/home.php with much of the work and updating carried out voluntarily by Robin Lucas G8APZ/F1VJQ.