Brought to you by PCS Electronics, www.pcs-electronics.com
42
Appendix A: DIY antenna and improvement tips
Simple GP antenna design
You can build an inexpensive 1/4 wave antenna from 1 so-239 chassis mount rf connector and 5 - 3' bronze welding rods,
cut to the proper length. Here is how it looks:
Fig. 19: »Do it yourself« GP antenna
For other antenna designs check our web site here: http://www.pcs-electronics.com/guide_antenna.php
Some more improvement tips
Think about purchasing SWR meter to tune and align your antenna. A good antenna system is extremely important and can
make up for a lot of power. For a suitable SWR meter check:
http://www.pcs-electronics.com/cn101l-daiwa-power-meter-p-347.html
If you can’t get much range with your homebrew antenna, have a look at these:
http://www.pcs-electronics.com/antennas-c-38.html
Still not enough range? Well, how about a 750W amplifier?
http://www.pcs-electronics.com/750w-digital-amplifier-19inch-rack-p-1295.html
Appendix
A
If you have a SWR meter,
leave a bit longer radiator
and adjust it later by
cutting
to
achieve
minimum SWR.
Most designs on the web don't compensate for the fact
that GP antennas are not wideband antennas. Here is a
Freq/element length chart for this simple GP antenna, all
element lengths are in millimeters:
Frequency
Radiator - B
Radials - A
108MHZ
660mm
693mm
104MHz
684mm
720mm
100MHz
713mm
749mm
90MHz
792mm
819mm
