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Old 06-05-2006, 08:06   #1
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H/H VHF

Whats the word on these? Icom has come out with a 6 watt while most of the ones I see on sale are 5 watt. Is the extra power worth paying for?

Most of the ditch bag lists include a h/h vhf as part of the contents. Are most cruisers equipped with 2 h/h vhf's, one for every day use and another in the bag with fresh batteries?

Whats the real world life span of these? Are the waterproof ones really able to stand up to being in the cockpit and dinghy over a long period?


The reason this question came up in the first place. Our VHF is equipped with a RAM mike which just failed after 2 yrs so I know its not that waterproof.

My question really boils down to should I buy a couple of sale priced units with the idea of replacing them fairly often or buy one high quality/power unit for daily use plus storing it in the ditch bag when on passage.

Thanks,

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Old 06-05-2006, 09:49   #2
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The prime factor, limiting com’ range ( 3-10 miles*) with Handheld VHFs, is antenna height, so I don’t anticipate any significant advantage in the extra (theoretical) watt (6W output vs 5W).

* A handheld VHF radio with antenna height 6 Ft , communicating with a receiving base station with a mast-top antenna mounted at 45 Ft.
Maximum Range = (1.22 x root6) + (1.22 x root45) = (1.22 x 2.449) + (1.22 x 6.708) = 1.768 + 8.184
Maximum Range = 9.952 Nautical Miles
VHF RADIO RANGE

FWIW, “Powerboat Reports” has an online test report on Handheld VHFs:
http://www.powerboat-reports.com/sample/vhf.html
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Old 06-05-2006, 15:37   #3
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Potential hazard

In addition to Gord's comments regarding practical range of a handheld operated near the surface of the water there is a power hazard beyond about 5 Watts operating near your front part of your head. The optic nerve is the tissue most susceptible to high levels of rf energy.

I feel that a 5 Watt (VHF and higher frequencies) level is a max safe one to use with an antenna right near your head. The ICOM 6 Watt handhelds are safe to use with their miniature plug-in mics (lapel speaker/mic) so that the antenna is over 18 inches away from your head OR// if you plug a coax to your masthead antenna into a 6 Watt handheld unit for greater range.

In general, one will not benefit greatly in an increase of power rating unless doubling (or more) the power when comparing units. Therefore, without other mitigating factors, do not concern yourself with an argument between 5 or 6 Watts. You are very unlikely to be able to tell the difference.
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Old 07-05-2006, 09:23   #4
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biggest problem with the h/h is battery. if you keep it for the grab bag, very likely that the battery will be flat when you need it. Some have a spare battery set up allowing use of standard AA batteries . Alternatively, you can get a very small solar panel designed to be portable, thus you can reckon on some power in the h/h

personally, I dont bother
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Old 07-05-2006, 13:25   #5
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Talbot, it's good to have one as a back up. I have needed once or twice and glad I had one.
There is another way of working out power and I won't go into boring detail, sufice to say, the difference between 5W & 6W in reality, works out to be marketing hype. You will get little difference in distance and a huge amount of battery drain for the result.
We are lucky here in the Sounds to have repeater stations high up on mountain tops. So the coverage is awseome.
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Old 07-05-2006, 15:05   #6
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jemsea-
The difference between a 5 and 6 watt rating may not exist in the radio. That's the maximum you will get from it, and unless the radio has been hand-tuned by a service tech it is not a perfect measurement but one that "average" components will have during an "average" build.
I'd be more concerned with the quality of the unit itself, i.e. whether it has a solid chassis and is physically robust, with water-resistance ratings and a warranty that backs them up. Cheap will work--but often, not as long. My h/t is a (gulp) 18-year old Standard Horizon, now part of Yaesu, but you can drive nails with it. Probably not as watertight as new radios, but it has lots of audio volume (cheap tiny radios often don't) so you can hear it clearly above all sorts of background noise. That's something most people don't look at in the store.

As Gord notes, the real range will be largely determined by antenna heights, but with most ht's they are also made to be convenient with a "rubber ducky" antenna. If you can get a tuned quarter-wave antenna to use with them, you can often increase the effective power. It may not buy you more range, but it can buy you a clearer signal even at the same ranges. The drawback is they'll be about 19" long and not so easy to protect or pocket.<G>

The comment about AA cells is also right on track. You can buy AA alkalines and expect them to stay reasonably fresh and not leak for two years. (Don't ask me how often I've found brand names leaking by 4 years.) Or, AA Lithium batteries at 4x the cost but with 2x the power and a 5-10 year shelf life. A great investment for the ditch bag, keeping a set of them in it.
Radios with rechargeable lithium (different chemistry) batteries get a lot of power out of them--but the batteries are expensive. Radios with NiMh batteries, most common, have less capacity and sometimes self-discharge inside of a month. Panasonic's NiMh batteries, made in Japan, seem to hold for six months. Generic Chinese cells used in lower-priced radios? Uhuh.
Radios with older NiCad batteries (if you can still find them) can hold a charge all winter, like my dear old clunker does.<G>
You'll also find that buying a 12-volt charging cord for the radio is a great idea, that way you can recharge it in the car/boat and while at sea.
If I were replacing mine, I think I'd want a radio with a battery tray that took AA but also offered a NiCad or Lithium tray to swap with it.
And then there is "DSC" which is still not common--but IS here to stay. It would be nice to have a h/t that also had DSC, dual or triple watch, and did all the rest. ICOM is a good brand and a major player but they're not really a "consumer mass market" company, so their products probably will carry a premium price.
If you can afford a dedicated ht for the ditch bag, great. If not? Just make a habit to keep the h/t somewhere near the hatch, near the bag, and make sure to grab it on the way out. It also helps to buy a waterproof pouch for the radio, and keep THAT in the ditch bag, since a radio in a raft is going to get wet at the least convenient time.
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Old 07-05-2006, 22:04   #7
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I have a Standard Horizon waterproof handheld. I think the number on it might be HX-350. I've been using it for nearly 10 years.

It is waterproof. I left it in the dinghy one night. It had the 6 x AA battery case installed. It rained heavily overnight and in the morning I found the radio submerged in the rain water that collected in the dinghy. It was a little wet in the battery case, but there was no sign of water incursion in the rest of the radio. I never really wanted to do that test on purpose...

The actual standard calls for surviving at a depth of 1 meter for 30 minutes, so overnight sounds pretty good to me. One of the dealers that comes to the boat show in Annapolis turns on a radio and leaves it in a transparent bucket on his table.

I can't speak for Icom, but the basic technology is rubber gaskets, so I don't expect they could have a problem.

It came with some special battery and charger, but that battery did not last very long before it wouldn't hold a charge. I only use the AA battery case with disposable alkalines. Rechargeable NiMH AA batteries work ok for receive, but unless they are fully charged, they don't have high enough voltage for transmit.

I agree with Rick's comments, with the exception that I would not be concerned about RF exposure from just 6 watts and a rubber ducky antenna.


I prefer to use the handheld for marina and bridge-to-bridge traffic when I can. My fixed VHF antenna is 53 feet above the water, so it can hear for miles. With the antenna so much lower, you don't get so much interference from distant boats. If the marina is only a mile or two away, I don't need the antenna height to talk to them.

I only have the one handheld, but I normally store it in the "cockpit box" with all the other stuff I take on deck when underway (bearing compass, horn, dividers, sunblock, etc). I would take that with me if ditching.
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Old 07-05-2006, 22:38   #8
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Many thanks!

I think my priorities now are being waterproof and able to use AA batteries.

John
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Old 07-05-2006, 22:52   #9
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Depending on your coverage a mobile phone is a good back up instead of a handheld vhf. We now have coverage from Wellington to the South Island all the way across the cook strait. A handheld vhf wouldn't have that.
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Old 08-05-2006, 01:07   #10
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Still no coverage around the top from Jacksons, Port Gore and on around for some way though Darryl.
Interesting though, I would have thought a H/H would still have triggerd the 1, 63 and 65 repeaters from way up where they are situated. Certainly once you trigger them, the coverage is simply staggering.
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Old 08-05-2006, 08:54   #11
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Mark, rubber gaskets and o-rings literally ARE always a problem, the question is not whether they will leak but only "how long until they leak". Which is why the warranties and pressure on them (depth) are limited. Also, if they are bumped (creating g-forces) or operating (flexing the rings) while wet, water is more likely to get past the seals. The seals will degrade from ozone, petrochemicals, and plain aging in any case. Knock wood, a good set of seals will last longer than cheap ones.<G>
AA batteries start out at 1.5V against 1.4~1.3 for NiMh which gives the AA an advantage, but NiMh and NiCd cells can supply more amperage during transmit mode, so in theory, if a radio is designed properly (and typically it may have more cells in the rechargeable pack than in the AA holder) it can be compensated or regulated and work well either way.

I don't know about Canada, but in the US cell phone users can dial *CG to connect directly to a local USCG dispatcher. Most of the cellco's have forgotten this number exists, but it starts you with USCG instead of a 911 center. If your carrier says "Gee, we never heard of that" as mine did, well, you can always call to find out.

Alan, you folks have repeaters on marine VHF?? I have no idea if that's legal for any use of it in the US. I suspect that if Congress knew the USCG had radios, they'd remove them from the budget in order to save more money. (USCG gets the short end of the budget here.)
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Old 08-05-2006, 15:34   #12
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Quote:
Rechargeable NiMH AA batteries work ok for receive, but unless they are fully charged, they don't have high enough voltage for transmit
The latest AA batteries designed for cameras have a much higher amp/hr rating than earlier, and some of the best are better than proper alkaline AA. Dont buy cheap ones

The best thing about alkaline batteries is their long shelf life.
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Old 08-05-2006, 16:46   #13
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Forget ones that need batteries. Buy the low end Uniden waterproof one for approx $100. It charges from 12v, so you can wire it directly into your system for charging. I have mine wired into an accessory panel so it is always fully charged up and ready to go. Using it as I would my standard ship's VHF (on all day, calling bridges with no end in the Erie Canal), I only had to plug it in every other night. It transmits in 5W and 1W ranges, does the intl. frequencies, WX, etc...

Now that I read what Rick wrote here... I will probably use it less often at 5W right next to my head.
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Old 08-05-2006, 22:04   #14
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Quote:
Originally Posted by hellosailor
Mark, rubber gaskets and o-rings literally ARE always a problem, the question is not whether they will leak but only "how long until they leak".
Of course. My point is just that I have no reason to expect that Icom is light years ahead of or behind Standard/Yaesu in their rubber gasket technology.

Quote:
AA batteries start out at 1.5V against 1.4~1.3 for NiMh which gives the AA an advantage, but NiMh and NiCd cells can supply more amperage during transmit mode, so in theory, if a radio is designed properly (and typically it may have more cells in the rechargeable pack than in the AA holder) it can be compensated or regulated and work well either way.
Yes, the radio could have been designed to work correctly at the lower voltage you get from using NiMH batteries in the AA pack, but this one wasn't. The batteries have the current capacity and work fine when fully charged. As the batteries discharge, the voltage drops. Eventually it gets low enough to trigger the low voltage detector in the radio, which triggers an alarm and shuts down the transmitter.

I guess the lesson here is this: If you think you might use rechargable batteries in the AA battery clip, check it out before you buy. If you will only use the special battery that comes with the radio, don't worry about it. My special battery doesn't work any more, so I would rather use regular batteries than spend a lot of money on a special battery for this radio.
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Old 09-05-2006, 01:42   #15
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Hi Alan,
If you listen to the trs from Mana you will notice that half the time we can't hear Malborough Marine from the Marina. It isn't until we get past mana island that we start to get the benefit of the repeaters. The mobile has 4 bars of service most of the way across the strait and inside mana. Around Komaru the vhf plays up a little too yet the mobile is superb. Telecom is improving the coverage all the time for the mobiles. A couple of years ago it was nowhere near as good.
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