When considering an SWR meter, pay
attention to its frequency range. For VHF use,
it must able to operate in the 162 MHz fre-
quency range. (Not all SWR meters do
because most are used by CB and ham radio
operators who only need a frequency range up
to about 30 MHz.) The Vectronics unit has a
range from 1.8 MHz to 170 MHz, and the
frequency-operating range on my ancient
Micronta unit is 144 MHz to 440 MHz.
SSB Antennas
SSB antennas are key to the effectiveness of
SSB radios—perhaps more so than with other
radio installations—because the goal is very
long range communication capability. Rather
than being concerned with a 20- or 25-mile
range, here we’re thinking in terms of hun-
dreds, and even thousands of miles! They are
also more complicated, since an SSB antenna
system has two parts: the abovedeck part, and
the belowdeck (generally in the bilge) counter-
poise part (see below). There are three types of
SSB antennas commonly used on boats:
1 Vertically mounted whip antennas are com-
mon in most powerboat installations.
2 Wire (or whip) antennas are common on
sailboats. The standing rigging (most
often the backstay) makes up part of the
antenna.
3 Halyard antennas are a new style catching
on among some cruising sailors. Here the
antenna is a rope halyard with a wire core of
a specific length. They are reportedly quite
effective and can be raised and lowered easily
when not in use.The Counterpoise
Thecounterpoise, also called a ground plane, is a
conductor or system of conductors used as a
substitute for earth or ground in an antenna
system. It is unique to wire or whip antennas
and is a necessary component for the antenna
to be effective. It allows the antenna to “see” an
image of itself; i.e., to effectively reflect and
transmit the radio signal. If the radiating por-
tion of the SSB antenna system doesn’t see its
reflection, it simply won’t work. Consider the
counterpoise the second part of the antenna
system. An inadequate counterpoise will most
often manifest as poor range reception for the
radio, especially at lower frequencies.
There are several ways to create a counter-
poise:- Use the hull of a metal boat.
- Add metal to the hull of wooden or fiber-
glass boats. - Install a copper screen on the inside of a
nonmetallic hull with a resin overlay to
keep it in place. - Tie into a ground plate that is in contact
with the water. - Use flat copper foil “tape” and attach it to
metal through-hull fittings. (According to
the NMEA, the tape should be at least
2 inches wide, but some manufacturers,
coaxial cable and antennas 177ART-2, Shakespeare, http://www.shakespeare-marine.com
SWR-584B, Vectronics, http://www.vectronics.com
AT-400, Bird Electronic, http://www.bird-electronic.comSWR METERS