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LF: MF/630M ANTENNAS

To: "rsgb" <[email protected]>, <[email protected]>
Subject: LF: MF/630M ANTENNAS
From: <[email protected]>
Date: Mon, 11 Jun 2018 17:04:31 +0100
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REF recent discussion about MF antennas
I have 3 antennas to choose from on MF/630M
 
For TX i use a 1/4 wave inv L, vertical section 32 metres and rest horizontal.
 
Next best RX antenna is MF/160M 1/4 wave inv L 26 metres vertical and rest horizontal again good capture area
 
Third antenna is a 1 metre magnetic loop and not as good as the above two antennas because of smaller capture area.
 
My experience on MF indicates that the larger the antenna the better the signal because of the large capture area
 
Smaller antennas do work after a fashion ie loops with suitable rf amps but some signals I cannot hear or are very weak compared to the larger antennas as described above
 
My QTH is out in the countryside well away from local urban noise and no overhead power lines, all utility services to the property are underground.
 
QTH is an important factor when determining suitable antennas.
 
Conclusion:-
 
Where possible use the largest antenna for the desired frequency , antennas with a large capture areas. Small loops, active antennas even with appropriate amplifiers are no substitute for the full size resonant wire antennas on MF or LF
 
Fortunately I have several antennas and can switch amongst them for received signal comparisons ie sensitivity, signal over noise etc
For TX a 1/4 wave inv L as high as possible with suitable insulated radials is a good performer also a full size 1 wavelength vertical quad loop, or a full size dipole inv V
Smaller antennas with loading coils for resonance and matching although functional are inefficient.
 
 
 
 
 
73 de MAL/G3KEV/IO94SH
 
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