My thanks to you all

Does MFJ make anything that will balance the line and tune without
amplifying the signal ? I've had an active antenna in the past but was very
disappointed with results - so I really don't want amplification.

"Robert Jeffares" wrote in message
...
In a balanced line you have two wires running in paralell between [in your
case] the receiver and the antenna. Depending on the size of the wires and
the distance apart you have a nominal impedance of 300 ohms or 600 ohms
which is fine for the input to the radio, but not so hot when you are
trying
to match into a centre fed dipole which is about 75 ohms.

There are ways of matching into a dipole from balanced line. The ARRL
antenna handbook is a great place to start learning about this sort of
thing. Your local library will have a copy.

The big advantage of balanced line is low loss. You can run it a long way
and have relatively low loss. A balanced line is not interference free.
It
should be less interference prone, but proximity to metal pipes or metal
in
walls can affect the "balance". Running balanced lines "on the twist" can
reduce these external effects.

It is called "balanced" because the same signal runs in both conductors
equal and opposite.

In some cases balanced line is used in an unbalanced configuration. Don't
get hung up on it.

Co-ax is unbalanced because the signal is conducted down the central
wire,
and the shield is connected to earth, and surrounds the centre core
supposedly stopping any radiation. Well that's the theory!

You can run 50 - 75 ohm coax from the centre of a dipole antenna to the
aerial input of your receiver but the further you have to go the more
signal
you lose. Purists use a balun at the dipole feed point because the dipole
antenna is a balanced device and the co-ax is unbalanced [ bal - un ] .

Coax is good because you can run it almost anywhere without having to
worry
about what it is next to as the earth shield surrounds the signal wire
[remember that's the theory]. Good co-ax costs. The stuff they sell at
Radio
& TV stores is rubbish. Pay the extra $ and get RG 58 or something as good
from a reputable supplier.

To get the best result from any antenna you need a GOOD EARTH. Now
depending
where you live this is easy. Bury a metre of copper pipe in the ground and
connect a copper wire to the pipe scraping the oxide off and making some
kind of soldered connection or using a brass fitting made for the job and
running the earth line in to the radio. A good earth connection will
eliminate a lot of noise. the reasons are too complex to deal with here.
The mains earth in your house is NOT good enough if you actually have one.
You need a Radio Earth. if you live on level 10 of an apartment complex
getting a decent earth may be harder to achieve. Water pipe is good, if
there are no plastic sections.

In any location the property you have access to determines how big an
antenna you can put up. Get the wire high and clear. If you can arrange a
centre fed dipole all the better, but end fed is ok for Rx. Coax is fine
in
most applications unless you have a really low signal from the station you
want to listen to. But spend time getting a good earth connection. When
you
have noise from flouro's and computers try hooking a good earth connection
onto the radio.

If you really want to get the best match try and find an antenna tuner at
an
amateur supply store, or hang around amateur radio junk sales. You will be
surprised how much of a difference a simple tuner can make. You can make
something that works from junk parts.

Happy listening

I have read that an unbalanced line can
be rid of most intereference if it s balanced, but not being an amateur
radio operator, I am at a loss to undesrstand the difference between
balanced and unbalanced lines

A lot of hams don't know the difference either!

Robert