Icom iM604A Review Manual page 7

The test group ran the gamut as far as front panel controls—from dedicated buttons and soft keys to traditional rotary knobs.
The displays on the Garmin 200 (#1), Icom 504A (#2), and Raymarine 218 (#3) all were rated Good.
After seeing the acknowledgement "Able
to comply" on the 500TR screen, users
key up the VHF and talk.
The IC-M424 performed well over-
all. It had the lowest power draw of the
group and had Good transmit power
stability. Both audio level and quality
were rated Good.
Bottom line: The IC-M424 offers very
good overall performance and a long list
of desirable features. We'd recommend
it as an affordable VHF for those who
already have an AIS or those not seeking
a VHF with built-in AIS.
icom ic-m504a
The IC-M504A is a compact, robustly
constructed radio well suited for the ma-
rine environment. It's the only radio of
our test group with a waterproof rating
of IPX8 (continual submersion in con-
ditions identified by the maker). It per-
formed well compared to the other test
radios, garnering an Excellent for trans-
mit power stability and a Very Good for
receiver sensitivity and frequency error.
The MM504A can connect to one re-
mote mic and can operate as part of an
intercom system. When interfaced with
a compatible GPS, it will display time
and position data, boat course, and boat
speed. Like all DSC Class
D radios, it will make
distress, individual, all
ships, and group calls.
Own ship and other ship
position data can also be
exchanged easily us-
ing the position re-
12 july 2012
e l e c t r o n i c s
1
quest or position report functions. The
received position info can be transferred
to external navigation equipment. The
polling (request reply) function checks
whether a specific ship is within the
communications range.
The M504A can store up to 100 MMSI
numbers and as many as 40 incoming
messages. Coupled with an Icom MA-
500TR Class B AIS transponder, calls
can be made to an AIS target using the
transponder without entering the tar-
get's MMSI number.
One-button control is available for
transmitter power, toggling between
weather and voice channels, and making
a quick channel 16/9 selection. Volume,
squelch, and channel selection are knob
controlled. Scan modes include dual-
watch, tri-watch, normal, and priority.
A low-battery icon blinks when input
power drops below 10 volts. The M504A's
large screen shows customizable chan-
nel comments, time and position, fre-
quency group, transmitter power, scan
tag, and transmit/receive icons. The unit
can accept a voice scrambler and comes
with a three-year warranty.
Bottom line: A good performer and
moderately priced, the IC-M504A offers
a number of useful and some unique
features. It gets a solid
Icom IC-M604A
Recommended.
icom ic-m604a
Icom's most so-
phisticated ma-
2
features an alphanumeric keypad, large
display, and a $512 price tag, making it
the second most expensive test radio.
The only test unit with a keypad, the
M604A had the largest footprint.
It can connect to two optional remote
mics and can operate as part of an in-
tercom system. When interfaced with a
compatible GPS, the M604A will display
time and position data, boat course,
and boat speed. Like the M504A, it will
transmit and receive position data, and
can store up to 100 MMSI numbers and
40 messages. Users also can call an AIS
target without entering its MMSI num-
ber when the VHF is coupled with the
MA-500TR AIS transponder.
The IC-M604A has the same scan
modes, one-button and knob controls,
low-battery warning, and displayed in-
formation as the IC-M504A.
As for performance, transmit power
stability was rated Good, while fre-
quency stability and receiver sensitivity
were Excellent. Audio quality was also
top notch, with an output of 97 decibels,
tying it with the Garmin VHF 200 as
the loudest unit.
Bottom line: This radio has very good
overall performance and numerous
user-friendly features. It gets PS's Best
Choice for a fixed VHF with a keypad.
raymarine 218
The Raymarine 218 offers a host of use-
ful features, including a moderately
sized display and a mount-anywhere
rine VHF radio, microphone option. It can also connect
the IC-M604A, to an optional remote mic to be operated
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