[UK-CONTEST] Reflections

[Ken Eastty]

John,

The reflections come from the airframe at least that's all that 23 or 
3cm primary radars see,
Watson Watt's 1935 experiment used a lumbering Hayford, that wouldn't 
have left much of a trail!

However...An interesting idea, it does at times seem to me that at VHF 
the reflected path does not always decay as soon as an aircraft has 
passed, when you think about it a 'heavy' jet generates disturbed volume 
in the atmosphere whether or not there are any visible trails.

I see that some wind shear radars operate at low VHF like the 64MHz one 
up in the Hebrides (&  54 MHz elsewhere) but these do run real QRO  like 
100kW peak power (ERP?) see: www.atrad.co.au/node/12/hebrides.

If (when?) Eyjafjallajokull  blows its top again (assuming there's 
another 'grounding' panic) perhaps a VHF contest could be quickly 
arranged to see if there's any significant difference to what's worked 
compared to 'Normal' conditions (whatever they are).

There's still quite a lot that we (or at least I) don't understand about 
the anomalies of V/UHF propagation much of which really only seems to 
show up in contests perhaps that's because these days there's so little 
activity the rest of the time. Sadly so many stations are only ever 
heard either during contests or when there might be an opening.

73...

Ken

G3LVP


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Message: 2
Date: Fri, 24 Feb 2012 22:34:54 -0000
From: "john  reynolds"<g3rsd at btinternet.com>
Subject: [UK-CONTEST] UK Contest re 23cm.
To:<uk-contest at contesting.com>
Message-ID:<B8353CBA858545D0A3FDDCE7BECCF5E4 at itsb11665>
Content-Type: text/plain;	charset="iso-8859-1"

I keep reading about the contacts made using reflections from aircraft and the advantage gained if this is a large aircraft.

Surely the most reflection comes from the trail left by the aircraft much more than the aircraft itself..........or, have I got it wrong??

John G3RSD