Re: [Paddlewise] VHF questions

I had been planning on staying out of the recent rounds of the handheld
VHF debate, but the advice that Dave Kruger and others are putting out
is, IMHO, just plain wrong.

First, I should make it clear that my recommendations are based on the
assumption that the number-one priority is to have a radio/antenna
combination that provides the best possible chance of getting through in
an emergency.  Maximizing your chances requires a good antenna, maximum
achievable power, and minimizing the risk of water damage. Dave's
recommendations will deprive you of all three, as I explain below.

(1) The antenna issue:

The use of a waterproof baggie precludes the use of a decent antenna
during an emergency. The rubber-ducky antennas have very limited range
in comparison with a telescoping antenna. Assuming that you are not in a
position during the emergency to safely remove your radio from the
baggie (a reasonable assumption!) you are stuck without the ability to
use a decent antenna just when you are in the greatest need. On the
other hand, a submersible radio can be fitted and used with a
telescoping antenna, even if you are in the water and subject to
periodic dousings.  This will greatly extend your range.

(2) The power issue:

The maximum transmit power for handhelds is 5 watts. But you cannot
achieve this with alkalines unless they are brand new, since they suffer
from significant voltage drop during use. Icom, for example, does *not*
claim that the M3A is a 5-watt radio when used with alkalines. See their
website--they make it clear that the 5-watt rating applies *only* when
using NiCads. I have two Icoms that can use alkalines (an M7 and an
M15), and I have spoken to Icom on this issue. They have made it
perfectly clear to me that they do not rate their radios as 5 watts when
used with alkalines. They ought to know. There is a reason that NiCads
are used in all high-end handhelds. They have consistent power output. 

Dave is absolutely correct, however, regarding the need to "babysit"
NiCads. They have to be carefully maintained and tested! With modern
equipment, however, this really is not all that difficult to do, and it
is worth it given their superior voltage performance. Dave is also
correct that NiCads have lower energy density, but he greatly overstates
the extent of this problem. The energy density of alkalines is about
one-third higher than for NiCads.  Adding 33 percent (or even 50
percent) to the weight of the batteries that you carry for your trip is
not an issue for sea kayaking.  As for the frequency with which you have
to change your batteries on a trip, it should be noted that not all
NiCads are the wimpy-capacity things that Dave has described. The
high-capacity NiCads that I use in my M15 have three times the capacity
of the standard NiCads used in older-generation handhelds. In short, if
you are willing to expend some effort in terms of maintenance and
testing, NiCads provide superior performance. (They also produce a lot
less waste, and are cheaper if you use your radio often.)  

If you decide that you do not want the hassles of NiCads (in spite of
their superior performance), this does not mean that you can't get a
submersible radio. I really don't understand the point that alkaline
battery packs are harder to seal.  Every alkaline (AA) battery pack that
I have seen seals in exactly the same way as the NiCad packs that they
replace. (See, for example, the very latest "submersible"--not
"waterproof"--designs by Standard and Apelco, both of which have a
manufacturer-supplied alkaline battery pack.) For most of these radios,
there is essentially no difference in the case itself or in the sealing
mechanism between the NiCad pack and the AA pack. For those radios that
do not have a manufacturer-supplied AA-battery pack (such as the M15),
the conventional approach to building one makes use of the case and seal
from the NiCad pack, simply replacing the "innards".  There are some
radios, such as the Icom M1, that have an usual battery pack that cannot
replaced with a AA-pack, but these are the exceptions. 

(3) The issue of water damage

I have used many different baggies from various manufacturers for
various electronic devices (VHF, cell phone, GPS), and a majority of
them have developed leaks. While some "submersible" radios also seem to
have an unacceptably high failure rate, others (such as the M15 and the
Navico handhelds) have excellent reputations in this regard, with
performance significantly exceeding the manufacturers' minimum standards
for submersibility. With either approach, you need to test your
equipment prior to a trip by dunking it for a significant period of
time. Make sure that the water is very cold, so that the radio is
subjected to a large temperature swing (this is necessary to really test
the seals). The first time you do this with an expensive radio there is
some trepidation, but it must be done. (Better to find out before you
need it.) If you do this, then whichever approach you take (submersible
baggie or submersible radio) you know that it isn't leaking at the start
of the trip. The question then becomes, which is more likely to develop
a failure subsequent to testing, the baggie or the radio seals? In my
opinion, based on the number of baggie failures that I have had (many)
versus radio-seal failures (none), I will go with the latter. I do
believe that my M15 is more rugged than a plastic baggie. If you really
want security, carry a back up. This is what I do. It doesn't add all
that much weight. 

Well, that's the case for submersibles and for NiCads. (Which are two
separate issues.)  To each his or her own.

Dan Hagen
Bellingham, Washington
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