Would you like to be able to hear more stations on
AM and Short Wave with your old radio?
If so there are several possibilities. First you want to decide if you want an Inside Antenna or an
Outside antenna. If an outside one.. be sure to make provisions for unhooking and grounding the
antenna when not in use. Don't take a chance on a lightning strike blowing up your radio.
First a simple 20 foot wire attached
to your radio
work and receive stations on
your old radio... Adding a ground wire to the radio will usually improve the
signals and reduce some of the noise your hearing.
In this next section you will be able to see an inside antenna that works well.
If you can get
a long wire up in your attic... you can have
a nice inside antenna...
This is a grid type of antenna that is simply stapled up to the roof
rafters in your attic... wire size is not important...
a #20 stranded wire works well... simply take your staple gun and a few hundred feet of wire up into your
attic and go back and forth as in the example picture above. Spacing between wires of one to two feet is fine.
In the above illustration you see Impedance Transformers ... Your old radio needs a high imedance antenna.. and a simple long single wire
is just that .. a high impedance antenna..... you can just drop one end of the antenna down to your radio... Or if you have
a noise problem with all sorts of noise generators in your home... perhaps you want to try to keep the antenna
away from the noise sources? If so, you can change the impedance of the antenna over to low impedance
using a small transformer... then use a coaxial shielded cable to get the antenna down into your radio... if you do this then
you have to put another transformer on the radio end of the coax to get the impedance back up for the radio.
These transformers are available in pairs from a local Ham Radio friend of mine who makes them up for
the Ham Radio guys who also use them ... we refer to them as Beverage Transformers as they are used by
Hams to correctly feed a "Beverage Antenna" ... Whats that you ask? .. well it isn't something you drink...
The antenna was invented by a guy named Dr. Harold Beverage ...
The antenna is simply a very long wire that is first of all close to the ground.... yes they work best if
installed between 4 feet and 10 feet above ground... the idea behind this antenna is that by keeping
it close to the ground and making it long enough... it will receive long distance radio signals and NOT
receive the atmospheric noise .... all those crashes and bangs you hear... they will be greatly
reduced in strength vs the desired signal your trying to listen to.... These antennas can be either a single
direction .... or bi-directional.... if you want a single direction.... then we put a carbon resistor of about 600
ohms at the far end of the antenna connected to a ground rod... if the antenna is left Un-Terminated then it will
be Bi-Directional.... to be really effective on the AM radio band a Beverage Antenna should be at least 500 feet
in length... and 1000 feet is a whole lot better... I have three of these Beverage Antennas ... mine are about 400 feet
in length because thats where I ran out of room on my property.. they run in three different directions... there are
times that I can listen to two different AM radio stations by simply switching from one directional antenna to
one of the other directions... with both stations on the same frequency. Here is an illustration of a beverage
By bringing the shielded coaxial cable in to the house you too will
no longer have to listen to all the
noise generators in your home.... Computers, Monitors, TV sets, VCR's, Variable Speed Ceiling Fans, Light Dimmers
and a whole list of other devices we all have in our homes...
John k9uwa and Gary kd9sv
The Impedance Matching transformers are available for $45 for a
of them.. Please add $4 for USA
Shipping. Outside USA email us and ask for postage quote...
One transformer is an inside design the other is designed for
outside use transformer... weatherproofed...
Type "F" connectors for easy installation of cable tv type coax
Contact Information for the above transformers
Gary Nichols KD9SV
email: "Gary Nichols" <email@example.com>