Rich,
Does your SGC-2000 suck that bad. My boat came with
one and a tuner. I have not had much time to play with
it so I don’t know how “good” it is. Although I have
talked to some guy from Texas and have listened to
one of the cruisers net when the weather is right and
the stars are aligned. I have purchased a pactor
modem this winter and plan to start messing around.
alan
— wrote:
owned a few dozen HF radios over the years. One of
my hobbies is restoring them. Each have advantages,
receiver performance, ease of use, filters, band
coverage, operator interface, frequency stability,
and optional features. None of the marine radios
that I’ve owned or seen can compete with a good HAM
radio, but HAM radios are not type-approved for use
on the marine bands. There are some marine radios
that are type-approved for amateur use, but this is
not the same thing. I keep two HF rigs on the boat,
and ICOM-706 and an SGC-2000. The 706 is a decent
radio, but is not outstanding. You can buy a good
used one for about $400. The SGC works OK on the
marine bands, but is really not a very good radio.
The matching tuner is nice however. Some folks use
their amateur radio on the marine bands. This is
technically illegal, though some amateur radios have
stability specs that are as good as the marine
radios.
So what’s the best radio? It all depends on what
you want to do with your HF radio and how much you
are willing to spend. If you just want to get on
the marine bands when offshore, a contemporary
marine SSB would work fine. If you want to keep in
touch with your cruising buddies over long
distances, you would probably find a HAM radio to be
of more value (along with the license to go with
it).
So what’s a band? Frequency allocation is done by
the FCC in what are called bands. The FCC will
grant use of a contiguous set of frequencies to a
radio service. This is called a band. In the case
of both the marine and amateur services, there are
band allocations scattered in the HF spectrum.
Because of the odd behavior of radio waves over long
distances and the influence of sun light and sunspot
activity, different bands can be used for
communication over different distances at different
times of the day.
So what’s the difference between marine bands and
amateur bands? Marine bands are channelized much
like a marine VHF radio. You dial in a channel
number. While you are probably aware of the band
you are working on, the actual frequency is of
little consequence. Marine radios are designed for
appliance operators. These are folks who just want
to make a contact with another station and don’t
want to be bothered with making adjustments to the
radio to make the received signal sound better.
Traffic on the marine bands is usually specific to
marine operations, though you may hear private
conversations at times. Amateur band traffic is
usually of three types, contest operations, net
traffic, and private conversations (aka
rag-chewing). Transmissions are done on random
frequencies within assigned bands. Contests are
what they sound like. You enter a contest and get
points for making contacts with other stations.
Points are awarded based on rules like where the
other station is. Net operations are done at
pre-arranged frequencies and times for a specific
purpose. The marine mobile net is a good example.
Here cruising folks can check in to see if anyone
has left a message for them.
So what makes one radio better than another?
Receiver sensitivity, selectivity, and noise
suppression (filtering) are probably most important.
The difference between two radios connected to the
same antenna can be quite dramatic. My SGC is deaf
in comparison with the ICOM-706 next to it. I can
receive and copy stations on the 706 that I can’t
even hear on the SGC. The 706 is deaf when compared
with an Elecraft K2 I have at home.
Wefax is usually transmitted on a band that is
neither in the marine bands nor the amateur bands.
The transmission is in a government allocated band.
The US has discontinued wefax transmissions because
it cost a few hundred grand each year to keep the
stations on the air. You can still receive wefax
broadcasts from Canada and overseas under the right
conditions. You can also receive precise time of
day. Most but not all marine and amateur radios can
be tuned outside their approved bands to receive
wefax and time. You can copy wefax, navtex, and
other digital mode broadcasts using either free
software or purchased software. Although you can
probably connect your laptop microphone jack
directly to your radio speaker output, I would
recommend buying an interface box to isolate the two
pieces (approx $150).
—
Rich Carter – BlackSheep #47
Original message
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