jg wrote:
I have done some reading about balun transformers and how I can connect
my existing flat antena cable to 75 ohm cable.

However, my questions is this... what if I replace the 30 year old flat
cable all the way to the antenna. Will this yield better reception?
(It is pretty good as it is.) The exiting flat cable is starting to
fall apart at some places.

When moisture gets into flat cable (300-ohm twinlead) it degrades the
signal. If the insulation is cracked and the wires are exposed, it
should be replaced all the way to the antenna. Don't use cheap twinlead.
The good kind has foam insulaton under the plastic outer insulation.
Connect the new twinlead just like the old one at the antenna. Clean the
antenna terminals with some electrical cleaner spray and a plastic scrub
pad. It might be better to replace the terminal screws, nuts and washers
with new ones made of brass or stainless steel. This may require cutting
and/or drilling the old screws off. They usually get corroded on an old
antenna.


Currently I just have it directly wired to
my coax cable (just before it enters the house) with out any type of
transformer. The coax is properly grounded (to the circuit breaker
box.)

If you decide to continue using twinlead to the antenna, you should
install an impedance matching transformer where the twinlead connects to
the existing coax. (See next paragraph below.) Twinlead has less signal
loss than coax so it's preferred in reception areas where signal
strengths are low. This may not apply in your case. Coax has greater
signal loss than twinlead but better immunity to noise reception from
home appliances. This is a consideration when deciding which kind of
antenna lead wire to use. If coax is used all the way from the antenna
to the TV it might require an antenna amplifier to make up for the
signal loss in the coax. The amplifier is installed on the antenna mast.
The power supply for the amp' is located near the TV.

So my questions are these:

1. How do I connect the coax directly to the antenna? Or should I?
Do I still need a balun transformer?

If you want to connect 75-ohm coax to a TV antenna which only has two
screw terminals for twinlead, you'll need an impedance matching
transformer. This is the kind which is used on the back of older TV's
that have antenna screw terminals instead of a female coax connector.
The matching transformer has a coax connector on one end and two wires
(pigtails) on the other. The pigtails would be attached to the two
terminals on the antenna and the coax goes to the female connector on
the matching transformer. You should use a transformer made for outdoor
use. You can buy one at Radio Shack or home improvement stores that have
a TV hardware department. The labeling will say that it's made for
connecting coax to a TV antenna which has screw terminals.

2. If I need a balun transformer, does anyone know of a heavy duty
outdoor one? (Or should I build my own.)
3. Will reception improve?

Matching transformers for TV use are not expensive, so it's not worth
the effort to make one. It's also not easy to make one that works well
at TV frequencies, especially UHF. Proper impedance matching between
antenna and lead wire is important for getting the best signal quality
to the TV.

Thanx to all who reply.

jg