[UK-CONTEST] Monobanders and height

[David G3YYD]

You will have noticed that the super stations have stacks of Yagis 
starting at about 30/40 foot and going up to as much as 200ft. The 
operator will select the Yagi "mix" for the best signal. Different 
heights will give different angles of radiation and so the operator will 
select the Yagi(s) to match the radiation angle. Ideally need both for 
optimum result. Don validates this with his observation as West Coast is 
generally a low radiation angle and the 100ft will have a significantly 
lower angle than 60ft.

Of course working stations a lot nearer than the West Coast could be 
better with a Yagi well below 100ft, may be below 60ft.

The different Yagis will have the same radiation angle for the same 
height, the forward gain will not be much different although the front 
to rear/side may be.

Some dual feed two Yagis and have them pointing in different directions 
say one on the US and the other on JA, if both directions are open at 
the same time.

Best answer is you need both and select one or other or both for best 
signal/coverage!

Some one said you can never have too many antennas and I agree. (The XYL 
has a different view).

David G3YYD

On 02/05/2010 13:33, Don Field wrote:
> Don't know about a 3-ele monobander, but I have vivid recollections of a
> situation on 20m at G0KPW some years ago. I was running West Coast long-path
> on the main antenna (5-ele monobander at 100ft). Dave G4BUO was bored at the
> mult station and decided to listen to my pile-up - mult station was a very
> respectable TH-5 at 60ft. I recall Dave telling me at the time that he was
> hearing very few of the US stations I was working. Distance between run and
> mult station antennas can't have been more than maybe 50 yards or so, so the
> difference was down to the antennas and/or their heights.
>
> Don G3XTT
>
> On 2 May 2010 13:07, Callum MØMCX<callum at mccormick.uk.com>  wrote:
>
>    
>> Our team is trying to establish the likely real-world difference on
>> 20m band, in extreme field-day style contesting, between an A3S at 60
>> feet and a full-sized 3 element  monobander with 16 foot boom at 100
>> feet.
>>
>> Does anyone have experience of these variables?
>>
>> Callum McCormick
>> Via iPhone
>> 07976 631881
>> http://www.m0mcx.co.uk/
>> http://www.barclayanderson.com/
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