Hello
Mal,
What
size and type of wire do you use in your loop??? Do you know the AC resistance
of the loop??? These are very important parameters, as Wild Bill would point
out. Maybe your loop has a very high Rac and this is why it performs poorer
than your huge vertical. Anyhow, let us know the wire size and such and we can
understand a bit more what you are using.
Thanks
es 73’s,
Hi
Mike and all
My
loop uses the same wire as the vertical antenna and radials. I use multi
strand 2.5 mm insulated electrical wire.
The
loop is vertical and the top wire is up abt 70 ft and its natural resonant
freq is 90 metres.
It is
about 20 db down on my vertical array on 136 khz.
The
loop is a good size by any standard but small relative to the frequency of 136
khz.
If I
went to a lot of trouble and used 3mm litz the RAC might improve but not
substantially and would not catch up on my vertical.
I
understand that under some circumstances like living on a small city lot, or
having a poor earth beneath the qth then maybe the only alternative to a
vertical would be a loop but does a loop not take up a lot more space than a
vertical.
In my
opinion if you want a big potent signal on LF then the only antenna is a
vertical configurated system. If you do not have the real estate for such an
antenna then you cannot do it, and will have to make do with what ever you
have.
I have
worked quite a lot of stations around EU and those using verticals are away
above the loops by a big margin.
For
anyone that is serious about LF then you need the acreage for the
antennas to make an impression. If you just want fun then try anything and
hope for the best.
Having
been interested in radio long before I reached my teens and got a licence in
my teenage years and was brough up in the countryside I always had the antenna
space and have always bought a suitable property for amateur radio purposes.
When I
lived in Hongkong/VS6HI I made sure that I picked a property with
about an acre for amateur radio acty in the New Territories and the same when
I lived in Singapore 9V1OY.
Not
interested in town or city lots - no good for amateur
radio.
73 de
Mal/G3KEV
Mike>WE0H
http://www.we0h.us/lf.html
185.3026kc QRSS-30 &
CW@15wpm
ID is "WE"
-----Original
Message-----
From:
[email protected]
[mailto:[email protected]]On Behalf Of hamilton mal
Sent: Monday, October 07, 2002 11:46
AM
To:
[email protected]
Subject: LF: Lasso alias
loop
What us
folks in the UK and Europe must remember is, that the USA boys are biased
towards loops(lassos). They were brought up on the ranches lassoing cattle and
naturally when it comes to radio this is the way they think, and its hard to
convince them otherwise.
Although my 90 metre
loop (natural resonance) is good it is not a patch on my vertical
system.
The
loop also has the disadvantage of being bi-directional, whereas the vertical
captures signals from all directions.
I find
on receive the loop is well down in its favourite direction from the vertical
and on transmit poor.
I am
not exactly comparing like with like because the loop is 90 metres and well
elevated, but my vertical is well over 100 ft and supports 3 x inv L antennas
each one 100ft plus, vertical and at least 300 ft horiz. Total inductive base
loading is less than 0.5 mh on 136 khz. I intend to improve on this
configuration when I get the time. The ground system consists of several 300
ft plus insulated radials. Both the vertical and loop are matched to 50 ohms
and fed with 50 ohm cable to the shack where all the equipment is designed for
50 ohms.The antennas and base feed are some hundreds of feet away from the
shack, away from any possible domestic electrical noise.
I think
the roundup days are over in America and they ought to try some verticals on
LF
The
next steamer leaving Belfast for Baltimore/Philadelphia is in 3 weeks time and
I might send over some verticals. This service has been operating since 1823
and is reliable, still using sails.
73 De
Mal/G3KEV
