From: "Mike Dennison" <mike.dennison@rsgb.org.uk>
Organization: Radio Society of Great Britain
To: rsgb_lf_group@blacksheep.org
Date: Wed, 3 Mar 1999 09:20:21 -0000
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Subject: LF: Success with small antennas
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Reply-To: rsgb_lf_group@blacksheep.org

>    First of all please let me introduce myself. My name is Des (M0AYF) and
> am currently a qrp H.F. operator (just a hint of qro :-) with an interest in
> L.F. I have only been on the mailing list for a few days since I only
> learned of its existence quite recently.
> 
>  If I may I should like to ask one very important and practical question, is
> it possible to make contacts effectively at 160 kHz with a proposed antenna
> which would only be about 25 feet high and about 50 foot long (horizontal
> wire or "T" resonated against ground) as this is about as much as I could
> ever manage within the garden of my town semi. In other words are there any
> operators on the list who are currently working with an antenna system with
> these sort of dimensions.

Des,

Several successful LF operators use small antennas, though it can 
be frustrating when listening to the big boys working DX. A Marconi 
T antenna will work well when tuned against a good earth. If you 
are able to get a light weight loading coil at the top of the vertical 
section this will help (use a 3 litre coke bottle). You will benefit 
from running high power - the beauty of the limit being ERP is that 
you can compensate for an inefficient transmit antenna by 
increasing power. The BK Electronics amps are useful for instant 
QRO, though the G3YXM and G0MRF amps are more elegant.

Although a basic T will work, there is lots of scope for ingenuity in 
bending an antenna to get the maximum amount of wire, carrying 
the maximum amount of current. Mine is triangular!

Also, spend as much time on the Rx system as the Tx. The most 
successful stations can hear well - and there are lots of 'deaf' 
stations out there - and some of those with smaller antennas have 
succeded by being able to hear lots of possible QSO partners. 

You are unlikely to do well from Day One, but patience and 
persistence in gradually improving your station will bring great 
rewards. I have twice heard people describe LF contacts from small 
antennas as "the most exciting in years of operating" and this is 
my experience, too.

My own antenna is bent into 60ft long by 40ft high - bigger than 
yours but smaller than many - and I have had more than a year of 
very exciting experimenting, making improvements and ultimately 
working several countries.

Good luck and I look forward to working you.

73

Mike, G3XDV (IO91VT)
http://www.dennison.demon.co.uk/activity.htm