Thread: 4Mtrs
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Old September 5th 05, 08:19 AM
Dave Piggin
 
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Hi All. Any good links for building 4Mtr beams for portable work or
permanent. TIA Dave.


4 Meters is not available for amateur radio usage in North America. RSGB
would be a logical reference source ... or adopt existing 6 meter or
commercial FM broadcast (88 - 108 MHz) designs. A standard 1/2 wave
driven element will be approximately 6 feet (or 2
meters) in length.


Uhm -rec.radio.amateur.antenna is a world-wide newsgroup


I find RSGB antenna designs to be disappointing. FM broadcast antennas
are too broad band. There is more mileage in scaling 6m designs, but you
can do your own better optimised design for 4m since it is only 500KHz
wide. I've an 11 element on a 15m boom -but its bandwidth is only
200KHz.


There is a good design here with construction details.
http://www.g1ogy.com/G4ZTR/4Mbeam/G4ZTR4mbeam.html


There are others if you search.


73 Brian GM4DIJ


Brian Many thanks for your link. As above, Yes I did understand that
70MHz wasn't available in yankland, but part of the authors answer was
irrelevant and as It's an antenna Ng, well. I have sourced a brand new
(bit dusty) Ex Military trombone 3 element yagi that doe's 50MHz to
100MHz, just got to do a few checks/calculations and suss it out, then
I'm away. Not a bad swop for a gutter mount Eh? Bomb proof material as
well as you'd expect from the MOD. Should last a bit longer than their
desert boots.

LOL Cheers Dave.

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