You are certainly NO EXPERT at amateur radio never mind LF/MF and especially
antennas.
I have worked the world on LF/MF using Inv L antennas with the far end just
above ground , and in normal CW mode.
Some time ago it was Comics, elevated lemonade bottles as coil formers,
thought an AR88D was a diversity fly catcher.
What is coming next? The diversity UMBRELLA!!!!
My current MF antenna is a full 1/4 wave inv L, 100 ft high and performs
well but for some this might be difficult, therefore use what you can get on
your property and let the far end tilt down if necessary.
G3KEV
----- Original Message -----
From: "Mike Dennison" <[email protected]>
To: <[email protected]>
Sent: Tuesday, May 12, 2009 10:29 AM
Subject: Re: LF: Re: Re: 500kHz Portable
You do not need 2 masts for an inv L or T antenna.
The so called horizontal wire(s) can slope down and the far end tied
to a bush or tree, or a stake in the ground via an insulator, as far
away as possible from the vert section, the longer the better. Keep it
simple. mal/g3kev
This is quite wrong. Any slope downwards will reduce the effective
height of a Marconi. Since ERP is a function of the square of the
effective height this is extremely important. An umbrella is far
preferable to an inverted-L in a single mast situation because a
large amount of capacitance to ground can be achieved without much
reduction of effective height.
Based on my experience of LF portable (both on 73 and 136kHz), my
advice is to make very sure that the remote ends of a Marconi are
very well insulated as they carry large voltages. Keep well away from
wet trees. This is not just a safety issue; any voltage leaked is
power lost.
Mike, G3XDV
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