Rubber duck antenna x Smiley

B

BrentB

New member
I have a SH HX851 handheld VHF radio and last night , was shopping online and visited Smiley Antenna site which has a replacement antenna with 3db gain. I don’t know the SH antenna specs and wondered if anyone has used a Smiley antenna and have any comments. I plan to contact SH and ask about their antenna specs.

https://www.smileyantenna.com/Default.asp[/i]
 
I have not used this antenna supplier. Brent asked the correct question--what is the gain of the standard Horizon antenna, which comes with the radio? My guess is that hit is 3 dB gain.

I have used several after market antennas, on 2 meter and 2 meter 440Mhz hand held ham radios. They seem slightly better than some of the antennas which come with the radios. One of the Smiley' has extensions to go from 1/4 wave to 5/8 wave so that the antenna is higher.

The radio is 6 watts, and limited by approximately line of site. No antenna, except one which gets it higher (maybe pick up one mile of range) will make a 6 watt radio on the deck, perform better than a 25 watt radio, with an antenna 10' above the deck.
 
Hi Brent


Thank you for contacting us with your email. What comes with the marine radios is a no gain omni directional antenna. A +3 dB gain antenna will most certainly give you better performance. However the antenna will be more rigid to from the base to the tip. Any damage to that antenna will cause a decrease in performance vs the stock no gain antenna.

Best regards,
Juan Hernandez
j.hernandez@yaesu.com

Yaesu USA
Standard Horizon
6125 Phyllis Drive
Cypress, Ca 90630
Ph: 714-827-7600
Fx: 714-527-9472

www.yaesu.com
www.standardhorizon.com
 
I'm not sure that the Smiley antenna covers the entire marine VHF band. The weather channels and some other operate at up to ~162.5 Mhz. The spec on the antenna is 150 to 160 Mhz. Depends on what the roll off of the gain is.

On the other hand, it does have a 3 db gain over the stock antenna, which would give added range. With the normal output of 5 watts, I understand that a 0 db antenna will get you 5 mi and 3 db more should increase that the 7.5 miles. At that range the horizon shouldn't be a problem.

They do offer a flexible 3 db antenna for $19. So they're cheap and should be worth a try.

Boris
 
The radio frequencies used in the VHF marine band lie between 156 and 158 MHz with NOAA Weather stations available between 161 and 163 MHz.
 
Here's a list of the VHF channels: USA Marine VHF channels. All the public correspondence channels are above 160, plus channel 20, port ops, and AIS. Granted that one does not use ATS on a handheld, but the others might come in handy. That can be as much as 20% of the advertised bandwidth of 150 to 160 Mhz.

If you want greater range or better reception, buy a smiley and and try it. You're only out $20.

Boris
 
The antenna will be at max "efficiency" where the SWR is the lowest--and if that is in the 157 MHz frequency area, this will be were most of the marine VHF frequency is located. 156.800 is Channel 16. Channel 70 DSC is 156.525 MHz.

The weather channels will come in fine and I doubt that you can tell the difference between the standard and any additional antenna. It is on transmit that any difference will be noticed.

AIS is slightly above this near 161 MHz--but that is not an issue with hand held antennas.

Boris, I am not sure where you are getting the 5 miles from 5 watts. But if the the conditions are good you can hit high repeaters or receivers from many miles away. If there is man made or natural interference, the radio with higher power will push thru better. But generally there is a "radio horizon" and that is slightly more than the optical horizon: For VHF radios held at 6' above the sea, this will be about 6 miles. Having 3 dB gain will not change that significantly. Now if the receiver is up 500 feet, then the range would be theoretically 35 miles, and you are more likely to get thru with a 3 or 6 dB gain antenna. But the radiation pattern is flattened with the increase of gain.

EPRIB or PLB transmitters are only 5 watts: Satellites are over 12,000 miles high. Their frequency is 406 MHz--also line of site.

Most of the information on VHF is from ham radio and military use. But the frequencies are close enough that it should be the same. In late Nov. of 1983, I was confined to our boat in Norfolk, VA. recovering from back surgery for a paralyzed leg. I had made contact with the local ham club on my 2 meter hand held (output 5 watts). Several members dropped by to visit. They decided it would be a news worthy if I could make contact with Owen Garriott (W5LFL) on STS 9, during his "open first ham in space" pass overhead. We had an acknowledgement of reception of my KA6PKB call. That was 155 nautical miles above our boat. In direct line of sight with 5 watts. I have worked repeaters 20 miles away with 5 watts on 2 meter ham radio a number of times.

There is an exception to the line of site with VHF frequencies; that is Tropospheric Ducting ducting. It is an atmospheric condition where the VHF radio waves are reflected back and forth between layers of atmosphere. I have talked clearly at a distance of over 325 miles at sea with a 25 watt VHF radio.

Now if you get the longer antenna, where you gain 2 feet, you probably will get mile or 2 miles more range. But then how "portable" is that radio-where does that antenna stick, when the radio is clipped onto the belt.
 
BrentB":soecgdc6 said:
Alas not waterproof
Click to expand...

I was wondering about that. If the antenna is "rubber" all except the connection end, maybe a good coating of liquid tape, or Rescue tape would do the trick -- at least make it splash proof.

Harvey
SleepyC :moon

9_Sept_Seq_2019_Cal.thumb.jpg
 
BrentB, I will be fascinated to hear how that Smiley antenna works.

I would not expect a great increase in range. This article, Antenna Range says that two antennae 12' above sea level has a range of 4.5 mi. That's reasonable on 2 C-Dorys. Doubling the power (3 db) doesn't increase the line of sight, but might help in marginal cases. The power received decreases by the square root of the distance, since it's a surface. So one may assume your range is now ~7 1/2 mile. Or since it's LOS limited, it may stay at 4.5 mi, but with better communications.

Boris
 
From the article that Boris cited:
Power output is often thought to increase range, but really, the difference in range between a 25-watt fixed marine VHF radio and a 5-watt handheld is due to the fixed mount's antenna being taller, and therefore it can "see" farther. More power will allow you to punch through static and other radio traffic better, but only within the range dictated by antenna height. Marine VHF radios work on a line-of-sight basis. That is, they can transmit and receive to and from another antenna as long as that antenna is above the horizon. How far is that? Standing in the cockpit of a boat, the distance to the horizon for most adults is about
Click to expand...

Since the line of site to the horizon is about 3 miles--communication between two boats, both at about 6 feet is 6 miles. But when you to to 12 feet off the water, the line to the horizon is about 5 miles, when you have two antenna's each 12 feet off the water, the total range is about 10 miles.

Say your buddy has an antenna mounted atop his large cruiser at 18 feet above sea level. Combined with the 12-foot height of your antenna, the two of you could converse while about 6.7 miles apart.
Click to expand...
. That is incorrect: The VHF range will be about 11 miles. The 12 foot antenna is about 5 miles, and the extra 6 feet only gains you a mile, or 6 miles, combine the two--11 miles.

Antennas do not alter the power. 5 watts out is all you get (if that) from a 5 watt radio.


From a ham radio site:
Unity gain (equivalent to 0 dB gain) ¼ wave antennas propagate RF in an omnidirectional, or circular pattern. Since an antenna does not make power, increasing gain in one direction will decrease propagation in another. Typically, antennas with gain will lose the vertical propagation or “roundness” of the pattern and become flattened and elongated with the higher gain antenna you choose. As you can see in the illustration, using a gain antenna may cause poor performance in a hilly environment.
Click to expand...

The images below are in ref to a land based vehicle on roads, but equate directly to a rolling boat. If you have a high gain antenna and the boat rolls or heels, you may actually have less of a signal in the direction you want. That is why on sailboats one uses lower gain antennas.
propagation.jpg.

Smiley notes for the collapsible antenna:

usable in 2 positions. Fully extended or fully collapsed. It is a true 1/4 wave when collapsed & 5/8 wave when extended
Click to expand...

So it is unity (1/4 wave) collapsed, and should be 5/8 wave extended, but here it gets a little dicey: There are other factors: ground plane (base loaded), also the question of impedance (which is a better match at 3/4 wave length)...

When used as a vertical radiator against a ground plane this translates to a length of 5/8 wavelength. It is found that a five eighths wavelength vertical antenna has a gain of close to 4 dBd, i.e. 4 dB gain over a dipole.

To achieve this gain the antenna must be constructed of the right materials so that losses are reduced to the absolute minimum and the overall performance is maintained, otherwise much of the advantage of using the additional length will be lost.
Click to expand...

The question is how are you going to measure any improved performance of the radio? It would be of interest to see where the resonate frequencies of the standard and Smiley antennas are? I see that the Simley is made of copper plated steel. It it is not waterproof, how will that hold up? Bring your radio to Hontoon, and we can put an antenna analyzer on it...but the problem may be connection to the SMA Male fitting. Would need a SMA male to BCN or PL 259 fitting. Putting an adaptor in costs about one dB. It would be interesting to do analysis on all of the Smiley antennas--because they have them for Marine 150 to 160, Air: 125 to 132 and 132 to 136, Commercial: 150, 160, 170 (plus a spectrum of the 440 to 460 public service range) and the ham 146.25 "tuned". and the 220 and 440 bands. At that price they are not hand tuning each antenna. I find a fair variation in the off the shelf Shakespeare VHF antennas resonate frequency which are far more expensive; which makes me a bit skeptical. I hope I am proven wrong. There is only. so much one can do with antennas on a small hand held radio, with multiple factors to consider.
 
Back
Top