SSB, Halyard Rope
JG-1 Antenna has been developed over the past 5 years by Dr. John Gregory, a
RF designer, with a specialty in marine RF communications. The antenna has
been tested extremely successfully on many different sizes and models of
original idea was developed when the Swedish Whitbread team required an SSB/HF
antenna that could be used during a race, with both minimal effort and high
gain for reliable communications. The design immediately became very
attractive to catamaran cruisers, as they have no backstay capabilities. The
convenience and compactness of the JG-1 Rope Antenna has now become so
popular that monohull vessels use it as either a backup antenna or as a
replacement /alternative to a very costly insulated backstay.
with Conventional Backstays:
Conventional backstays are installed by rigging companies that have little
or no knowledge as to the necessary electrical RF design length for the
all backstays are
entirely too short
Neglect of a necessary second insulator at the top end on the backstay, to
prevent skin RF effects when covered with salt from the air and ocean mist.
Stainless stays are a poor conductor of RF energy.
possibility the insulator to breaks loose under extreme torque, (during a
rough passage). The backstay carries more weight and “g” forces then any of
the other stays, so why risk altering it?
Rope Antenna uses a strong Staystat halyard line manufactured by New England
precisely measured length of copper wire, with a tinned coat of silver
nickel and an outside insulator is carefully inserted into the core of the
the key successes of the JG-1 Rope Antenna is that this precise length of
wire floats inside the halyard, and thus is never being stretched, under any
conditions. Even when the mast sways, only the halyard stretches, leaving
the copper antenna line always the same precise and correct length. This
means any antenna tuner will not be hunting for new RF resistance at the
given frequency throughout the day due to the continual stretching of a stay
or other antenna.
are 3 major variables that are necessary to the design of any antenna to
work with all-major automatic antenna tuners on today’s market.
variables for antenna matching are RF resistance, reactance, and good RF
grounding for the antenna counterpoise.
model of the JG-1 Rope Antenna is precisely designed for the correct
resistance and reactance for the length that will fit your boat, but the
grounding you require inside your boat is equally important no matter what
antenna you install.
part of the antenna cannot be more emphasis. The importance of taking the
time and effort in the constructing of a good ground, and most important,
the counterpoise radials.
years of extensive testing, here how we address the grounding and
counterpoise system for your vessel.
Normally, the antenna tuner is located in the stern lazarett or locker. It
should be mounted in an area that would be dry and easy access to maintain
it often. Maintenance to an tuner is making sure that the radiating terminal
is always clean, the wires are not pinched, bent, and are free from other
electrical, and control circuits cables that are near equipment, such as the
auto-pilot control lines.
main ground lug on the tuner should be connected via a 1-2 inch copper
strap, and within 5-7 feet of a ground shoe. This ground shoe should be a
copper/ bronze plate mounted outboard. There should be NO other electrical
lines connected to this plate from the inside, other than RF related
electronics. This ground is the electrical ground return from earth ground,
except that your earth ground is now the salt or brackish water.
same grounding terminal on the auto tuner you now layout the counterpoise
lines for your antenna.
recommend that 2 lines be constructed on both port and starboard under the
floorboards, in the bilge area, below the water line.
counterpoises become the reciprocal to the antenna that is above the deck
and connected to the top of the mast or mizon.
counterpoise lines for the antenna are connected to the same wing nut on the
antenna tuner as to the grounding to the ground shoe.
past 2 years, we have experimented using 450-ohm twin lead antenna line,
which performed with outstanding results. The following is what takes place.
counterpoise lines for the tuner and antenna is twin ladder 450 ohm ladder
side of the vessel either port or starboard, we cut the ladder line at
approximately 42-47 feet. This counterpoise has good RF resistance for
frequencies in the low marine bands, which also support the amateur bands.
opposite side of the vessel, again below the water line, the same 450 ohm
ladder line material, is cut to 32 feet from the start of the autotuner.
This line gives a good RF resistance and reactance to the auto tuner for the
bands below 12 MHz.
best to have the lines on the port and starboard side separated by at least
ladder line should be any length from 32 to 27 feet for the one side of the
ladder line and the second side of the ladder line is cut to 17 feet. This
side supports the higher frequencies, from above 12 MHz.
auto tuner feels comfortable as to tuning the JG-1 or a basic well-cut
instrument to check the output of the antenna tuner is using a simple SWR
meter. Simple does not have to be expensive and covers the entire HF bands.
find by adding the counterpoise and a good grounding system that not only
you lower the noise level of the radio, but also you will get better
reception, more power output, and signal reports.
JG-1 Halyard antenna works exceptionally well with the following tuners,
120,130,140, Icom AH 2,3,4. LDG, all tuners, SCG 230.
our extensive testing the entire above antenna tuners worked exceptionally
JG-1 has been on the market for the past 12 years, and with great
2 Coils of ladder line, ready to install