BoatingLAB Tests: VHF Antennas | Boating Magazine

BoatingLAB Tests: VHF Antennas

Everything you need to know about your boat's antennas.

Longer broadcast and reception range is definitely better than shorter range, and longer antennas definitely give better reach.

That was BoatingLAB’s conclusion after lining up five popular antennas and calling to a mobile station at one- and five-mile ranges. Eight-footers, installed seven feet above sea level, all reached our mobile station five miles away, but shorter units lost their reach quickly after one mile. That’s only logical since a VHF signal travels via line of sight and antennas are made to polarize their signals on a horizontal plane.

But we wanted to know if you could hear a distinction between the signal and sound quality of a higher-priced antenna and that of a lower-priced antenna. The answer was an inconclusive “not really.”

Aside from signal reach, we found important differences in components that justify the added expense.

We tested two high-end VHF antennas ideally suited to a ­powerboat from 20 to 40 feet long. We also took a look at one value antenna and two short antennas suited to small boats or sailing vessels.

Pricing for our test antennas came from online retailers whose price points often reflected ­bargain prices on premium products. The ­slider bars on price/value are not influenced by those prices but by our assess­ment of quality components and manufacturers’ product positioning.

Here’s our test.

VHF Explained
Gain Average
Gain is the degree of polarity, or horizontal focus, of the signal. The more gain, the thinner the horizontal beam. A 6 dB gain is quadruple a 3 dB gain. A 9 dB gain is eight times the 3 dB gain and should be reserved for land-based stations. On a rocking boat, the signal would be aimed too high and too low to be received.

SWR
Standing wave ratio is the amount of resistance to the signal an antenna exhibits. An SWR of 1:1 is ideal but usually unattainable. Your installation should reflect an SWR meter reading equal to the radio’s specifications.

Max Input
Recreational VHF radios are limited to 25 watts of output, but land stations can be permitted for higher transmission power.

Termination
RG8/X is the higher grade of coax used on VHF antennas in our tests. The higher grade better resists signal interference.

Length
Since the VHF signal is line of sight, the taller antennas reach farther over the curve of the earth.

Radio Horizon
Range for one antenna with a 15-foot height.

Tested Range
This is the range at which the signal in our tests began to deteriorate.

Coax Supplied
Each connection in the cable adds resistance to transmission. A longer cable means fewer connections and better transmitting and receiving dynamics.

Ferrule
Stainless steel is better than chromed brass, which will pit. Plastic ferrules should be used where short-term life expectancy is acceptable. Polished stainless steel won’t pit or corrode as readily as chromed brass.

Radome

This is the fiberglass shaft that supports the antenna elements and protects them from ­weather. The better ones are finished with a durable polyurethane coating that protects the resins from the sun and prevents fiberglass shards from splintering on hands and deck.

Shakespeare Galaxy 5225-XT
Twenty feed of higher-quality RG8/X coax is a plus on larger boats. It also has a high-quality gloss finish to protect the radome from the elements. This was the only antenna with a stainless-steel ferrule, which will be much more resistant to corrosion, pitting and UV degradation.

Specs
Gain Average: 6 dB
SWR: 1.5:1 at 156.8 MHz
Max Input: 100 watts
Antenna Length: 8 feet
Radio Horizon: 5.3 miles
Tested Range: 5 miles
Termination: RG8/X
Coax Supplied: 20 feet
Ferrule: Stainless steel
Radome: Solid fiberglass laminate has a 22 mm diameter at the base and 11 mm at the tip. The composite core is heavily coated for protection and good looks.
Warranty: 5 years
$134 plus shipping;
amazon.com

Glomex RA1225
A high-gloss finish protects the thicker radome fiberglass, but the coax supplied was RG-58 and only 15 feet were provided, possibly requiring a costly power-robbing splice. The chromed brass ­ferrule is adequate for the challenge of the elements, but not as ready for it as the Galaxy 5225’s stainless-steel ferrule.

Specs
Gain Average: 6 dB
SWR: 1.3 at 156.8 MHz
Max Input: 100 watts
Antenna Length: 8 feet
Radio Horizon: 5.3 miles
Tested Range: 5 miles
Termination: RG-58
Coax Supplied: 14.7 feet
Ferrule: Chromed brass
Radome: The two-layer laminate has a base of 24 mm and tapers to a 9.5 mm tip. It has a glossy coating for protection of the composite core.
Warranty: Lifetime
$78.99;
amazon.com

Shakespeare Centennial 5101
The only value-point antenna we tested is not the cheapest, but a midrange model. It worked well in our tests and was audibly, at least, as effective as the premium 8-footers. It sports a shorter length of less-expensive-grade coax, is not as glossy as the others, and bears a shorter warranty period.

Specs
Gain Average: 6 dB
SWR: 1.5:1 at 156.8 MHz
Max Input: 50 watts
Antenna Length: 8 feet
Radio Horizon: 5.3 miles
Tested Range: 5 miles
Termination: RG-58
Coax Supplied: 15 feet
Ferrule: Chromed brass
Radome: This antenna has a thinner radome of 20 mm at the base and 6 mm at the tip.
Warranty: 2 years
$60 plus shipping;
amazon.com

Shakespeare 5241-R
The lower-gain antenna is best used in a smaller boat apt to rock excessively or at the top of a sailboat mast. Lower gain means a wider-focused beam that is less impacted by rocking.

Specs
Gain Average: 3 dB
SWR: 1.5:1 at 156.8 MHz
Max Input: 50 watts
Antenna Length: 3 feet
Radio Horizon: 4.5 miles
Tested Range: 2 miles
Termination: RG-58
Coax Supplied: 15 feet
Ferrule: Chromed brass
Radome: Stainless-steel whip
Warranty: 2 years
$60 plus shipping;
amazon.com

Glomex RA106SLSPB6135
Slightly longer than the other “short” antennas tested, this one came with a mount, the height of which we subtracted from the specifications below. It’s still the longer of the shorties. It came with 19 feet of coax, several feet more than the 14.7 feet listed in the specification sheets.

Specs
Gain Average: 3 dB
SWR: 1.3 at 156.8 MHz
Max Input: 100 watts
Antenna Length: 3 feet 7 inches
Radio Horizon: 4.5 miles
Tested Range: 2 miles
Termination: RG-58
Coax Supplied: 19 feet
Ferrule: Chromed brass
Radome: Stainless-steel whip
Warranty: Lifetime
$60 plus shipping;
amazon.com

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