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Head to head of fixed VHF Marine Radios

Head to head of the fixed VHFs

Last month we tested hand held VHF radios. This month David Kerr reports on seven fixed VHF radios from GME, Icom, Navman, Oregon Scientific and Raymarine.

Nearly every cruiser I have spoken with has been positive about his/her VHF. They are generally reliable and work well. Over the past few years, the major changes to VHF radios have been better waterproofing and the addition of Digital Selective Calling (DSC). Most of the radios tested came with DSC.

Do you need DSC?
The Australian Government supports HF DSC in Australia through its Wiluna and Charleville stations. There is no equivalent State or Federal Government support for VHF DSC. However, the Volunteer Marine Rescue organisations are beginning to equip with VHF DSC and all ships over 300 Tonnes  monitor the DSC channel while under way. Mandatory VHF voice watch for ships was to cease in January of this year, but has now been extended, perhaps indefinitely. A good quality fixed VHF marine radio should last up to 10 years; so, if you already have a good non-DSC VHF, I would not rush out to change it for a DSC unit. On the other hand, if you are in the market for a new radio, I would definitely buy a radio with DSC capability. This will also be necessary if you plan to cruise to the US, Canada or Europe.

If you and friends have DSC radios, you can set up to digitally call each other. With some radios, you can even poll your friends automatically for position reports and track them on a chart plotter! As you might imagine, this is a current fashion in the US, particularly amongst power boaters. As more VMRs equip with DSC, more people will call them on DSC thus avoiding congestion on channel 16. In practice,  I have found that calling ships using DSC is more successful than voice. As you'll see later in this article, I accidentally transmitted a DSC Distress Call and the response was swift.

Installation
VHFs are much easier to instal than HF radios.  All the user manuals gave good advice and templates are provided for flush panel mounting (which is normally an option at an additional $11-$30). Many are mounted using a simple bracket which enables overhead, side or bottom mounting with easy swivelling of the unit. Current drain of all tested radios is less than 6 amps, so power wiring is relatively uncomplicated. However, I have observed two chronic installation problems which are worth highlighting here:

All but  two of the tested radios came with crimped connections. One of these crimps even fell apart as I removed the radio from its box! One of the instruction manuals urged the reader not to use crimped power connections but they were still provided on the radio. Crimped connections have no place on any boat and will likely give trouble- usually when you could do without it. The solution is simple- cut off the manufacturer supplied crimp connections and solder everything and/or use quality, plated plugs and sockets (which were supplied on the GME GX600 and Raymarine 240e).

b. VHF is usually line of sight. You can experience �Troposcopic Ducting� which allows communication over hundreds of miles, but this is not common. For this reason, the best place for a VHF antenna is usually on the top of the mast. The distance (and any obstructions) usually have more influence than the amount of power used. However, more power is still best and will make your signal more readable in poor conditions. As an analogy, you rarely use the full power of your car engine, but it's useful for hills and other situations. Would you knowingly reduce the power of your engine to a quarter or less? No! Unfortunately many marine VHF installations DO suffer an equivalent loss of power due to inadequate coaxial cable necessary to carry the signal to and from the masthead. One expensive production yacht I inspected, was putting 5 watts (from its 25W radio) into the antenna! If the cable distance from your VHF to the antenna is 15metres, you'll lose half your power if you use the common 6mm RG58U. Beyond this length of cable, I strongly recommend using 11mm RG-213 cable. Yes, it's heavier, larger and more expensive but you'll get far better performance as the power loss is only a third of RG-58U.

What's important?
Modern VHFs tend to be solidly built and work well. In general, reputable manufacturers are reasonably honest in their specifications. However, transmitter performance is often measured at 13.8V which is unrealistic on the average yacht unless some sort of generator is being run or a stabilised supply is in use, so I used 12.5V. I also tested the minimum voltage at which the radio would still work- lower is better if you're in trouble and the batteries are damaged. Standby current drain is also important as a cruising boat frequently needs the radio on all the time.
The following were tested:

Power output (versus voltage).
Receiver sensitivity.
User manuals.
Ease of use.
Standby current drain under different conditions.
Audio quality.
Manufacturer/Distributor support.
User and Installation manuals.
Scan options and speed.
DSC capability.

Made in China
Four of these radios are manufactured in China. Exceptions are Icom which is made in Japan, one Raymarine made in the UK and GME manufactured in Sydney. Many electronic components are now made in China and I have printed circuit boards made there with excellent quality. So, is the quality of a Chinese radio as good as from elsewhere? The jury is still out, but the final quality of a product depends mainly on the design, the build specifications, the components, testing and quality controls. In our new global economy, country of origin is far less important than 10-20 years ago.

Navman Antenna
Navman kindly lent me a large fiberglass VHF antenna to assist with testing. This is the sort of antenna you would mount on the deck as it is approximately 2.5metres high. It came equipped with swivel mounting, cable and all appropriate connectors. Performance was impressive and for the technically minded, the antenna was beautifully matched with almost zero reflected power across the entire VHF marine band when mounted 1 metre above the ground/water. Effective radiated power in the horizontal direction will be approximately twice that of a smaller mast head whip antenna but you'll lose the height advantage. RRP is $89.

Common features and performance
All of these radios have low power settings of 1W which they achieved in practice. All achieved their specified 25W high power performance. However there were differences in my "real world" voltage tests.
All squelches worked well and were easy to set, 'though I still prefer a rotary knob. Channel changing was by rotary knob or direction keys (the 240e also allows direct channel entry). Some provided an alphanumeric channel display.
All had usable scan facilities, but there were big differences in scan speed and also the number of available scan modes.
All radios came well equipped with cables, screws, fuses etc and could be bracket or flush mounted.
For the technically oriented, there was only 5decibels difference in receiver sensitivity between the best and least sensitive radio receivers. See "Features at a glance"for the ranking.
All DSC radios had the basic necessities such as a protected and lit Distress button, loud alarms and the basic DSC call types. However, some radios had more complete functionality than others. In particular, the International Telecommunications Union  DSC specification calls for VHF DSC radios on ships to be able to initiate a Distress Relay call, but this was not possible on some radios (see detailed descriptions).

Summary
What you choose depends upon your budget and what's important to you. I would be happy to sail on a yacht equipped with any of the tested units. My personal preferences are shown in the "Features at a glance" box.

GME GX600
RRP $325. Made in Australia.
Size (mm): 164Wx77Dx65H. Weight: 730 grams.
Strengths: Structural strength, sensitivity, intermodulation performance (i.e. the ability to reject adjacent channel interference), size, different back light colours. Good waterproof power connection.
Weaknesses: No GME DSC radio (but see the new model when released).
Knobs: One, for volume/power.
Standby drain, scan and no back light 0.151A.
Standby drain, scan with max back light 0.217A.
Lowest operational voltage 8.0V
Power @ 10.5V=19W; 12.5V=25W;14V=25W
Current at 12.5V/25W=3.73A.
Scan: 10 chan/sec
External Speaker: Yes
Waterproof to IP67
This is a well engineered non-DSC radio. It is far and away the smallest and lightest of the radios tested with excellent technical specifications and good audio quality. With a metallic body, the radio has far less plastic than other radios. The display has three different back light colours (green, red and orange). Squelch is 10 level digital with override. The radio has dual and tri watch, programmable memory channels and programmable working channels (A and B). It also has Normal, Proiority and an enhanced Priority scan. By the time you read this, GME will be close to releasing a new VHF-DSC radio. Their chief design engineer told me exactly what is in this new radio. Based upon my testing of the GX600 and what I understand will be in the new one, it will certainly be worth evaluating. GME will be basing the new radio upon the GX600 innards and aiming for a competitive (i.e. low) price point.
Icom M302
RRP $396. Made in Japan.
Size (mm): 153Wx132Dx67H. Weight: 872g.
Strengths: Fast scan. Good back lighting, DSC address book size, overall display, manual, low volt warning.
Weaknesses: 5 character DSC/channel display area. No call log for received DSC calls.
Knobs: Two for volume/power and squelch.
Standby drain, scan and no backlight 0.162A.
Standby drain, scan with backlight 0.217A.
Lowest operational voltage 6.5V.
Power @ 10.5V=21W; 12.5V=25W;14V=25W
Scan: 11.4 chan/sec (Priority 6.7).
External Speaker: Yes
Waterproof: JIS7.
There are four Icom VHF radios and the 302 is the low end unit at the lowest price. The 402 (RRP $654.50) allows the addition of a second station (e.g. at the helm). The 502 (RRP $874.50) permits scrambling and has larger knobs plus a much better display than the 302 for DSC and channel labels. The 602 has two command mics, loud hailer and other functionality.
The microphone has backlit buttons for high and low power, Ch16 and channel up/down. There is also a neat facility to lock out these buttons which are sometimes a nuisance when you inadvertently press one.  The radio has dual and tri watch with  Normal and Priority scan. The (programmable) Ch9 key should be renamed as this the second priority channel is not 9 Internationally...
Channels can be labelled with 10 characters of information (which scrolls in the 5 character area on the screen). Icom has a range of extras available, including a front dust cover.
DSC. The address book holds 30 entries with MMSI and five character name. Five characters is a little limiting but 30 entries is more than any of the other radios. The radio handles distress, grounp and individual calls as well as position requests and reports. It will not initiate a Distress Relay call nor is there a call log.
Navman 7000
RRP: $299. Made in China.
Size (mm):161Wx75Hx147D. Weight:  1250g.
Strengths: Excellent display.  Receiver sensitivity. Good controls. Manuals.
Weaknesses: Slow scan. Lack of lighting for the buttons makes night use difficult without a torch.
Knobs: Two for Power/volume and squelch.
Standby drain, scan and no back light 0.170A.
Standby drain, scan with max back light 0.220A
Lowest operational voltage 7.5V.
Power @ 10.5V=19W; 12.5V=25W;14V=25W.
Current drain at 12.5V/25W=4.9A.
Scan: 3.7chan/sec
External Speaker: Yes
Waterproof: JIS-7.
The microphone has channel up/down buttons, Hi/Lo power, favourite three channels and a channel 16 button. Even though this is not a DSC radio, a GPS can still be connected and the radio will display position and time information.
Navman has done a particularly good job on its manuals for the 7000 and 7200- there is a quick guide, an installation manual and an operations manual. The user can program names and channel descriptions for each channel. The unit has dual and tri watch. The (programmable) Ch9 button should be renamed.
There is a Distant/Local switch, which is useful for reducing inter-channel interference from strong stations in crowded harbours or  close to powerful transmitters. Just remember to reset the switch when you leave harbour! This radio and the 7200 come with a dust cover as standard.
Navman 7200
RRP: $499. Made in China.
Size (mm):161Wx147Dx75H. Weight:  1200g.
Strengths: Excellent display.  Receiver sensitivity. Good controls. Good DSC. Manuals.
Weaknesses: Slow scan speed. Lack of lighting for the buttons makes night use difficult without a torch.
Knobs: Three for volume/power, squelch and menus.
Standby drain, scan and no back light 0.175A.
Standby drain, scan with back light 0.22A
Lowest operational voltage 7.6V.
Power @ 10.5V=19W; 12.5V=25W;14V=25W.
Current drain at 12.5V/25W=4.95A.
Scan: 3.7 chan/sec.
External Speaker: Yes
Waterproof: JIS-7.
The 7200 is an enhanced version of the 7000 so those comments also apply.
The 7200 microphone has inbuilt temperature and barometric pressure sensors. The data from these can be displayed on the radio, including 24hrs of barograph data plus �good fishing� indicators and weather icons. The icons won't be meaningful in the tropics. The barograph is particularly useful if you do not have a recording barograph or do not do a good job regularly logging barometric pressure. It continues to gather data even when the power switch is off with 0.012A drain or a miniscule 0.3 amp hours per day.
DSC is well implemented on this radio. It logs the 20 most recent DSC calls received as well as the most recent 10 distress calls. There is the usual GPS disconnected alert plus the ability to manually enter GPS data. The �Buddy List� stores 20 MMSIs and alphanumeric descriptions which are used on incoming as well as outgoing calls. There is an automated �Buddy Track� feature for automatically polling another vessel and obtaining its lat/long. This data is output on Navman's bus connector. The radio has a GPS simulator for training or practice purposes.
Oregon TM338
RRP $299. Made in China
Size (mm): 168Wx175Dx72H. Weight: 1245g.
Strengths: Price, controls, display. Best standby current drain.
Weaknesses: Manual. Soft white knobs get dirty easily. No DSC position requests or reports. Non programmable "Ch 9" button.
Knobs: For channel, squelch and volume.
Standby drain, scan and no back light 0.145A.
Standby drain, scan with max back light 0.192A
Lowest operational voltage 10.5V.
Power @ 10.5V=15W; 12.5V=20W;14V=25W
Scan: 5.2chan/sec.
External Speaker: Yes.
Waterproof: JIS7.
This unit has a large display with a good controls and layout. Back lighting of display and keys is good. Scan is Priority Mode only. However you can scan the 10 programmable channels to get something like the normal scan mode of other radios. The �Channel 9� button can not be re-programmed for Australia. The manual is okay, but the English needs some work. You'll see from the photographs that the microphone is not a traditional shape, but it works well and has useful functions such as high/low power, Ch16 and channel up/down.
One caution. The crimped power connectors were made up to be the reverse of the industry standard! No problem if you cut them off but I had to be doubly careful on the workbench with all those �normal� connectors around!
The backlit display is good and shows longitude, latitude and time as well as the normal channel display. Time can be UTC or local. The back light is adjustable. The channel selector is a knob.
The DSC was easy to use. The in built log stores 20 individual calls and 10 distress calls. There is a �buddy list� which uses a 12 character alias instead of the 9 digit MMSI. This is used on transmit and receive. The radio successfully handled Distress, all-ships, individual and group calls. There is a �Call back� facility for received individual calls. There was no facility for DSC position reports or requests. I could not initiate a DSC Distress Relay call.
Raymarine 240e
RRP $1479. Made in the UK.
Size (mm) 273Wx178Dx67H (Main unit). Handset 120x99.5x46
Weight:  1900g. (Without the supplied external speaker)
Strengths: Ease of use, handset/keyboard design, receiver sensitivity, excellent display, manual, DSC, low voltage performance.
Weaknesses: Price, need for separate on/off switch, high standby current drain.
Knobs: One for speaker.
Standby drain, scan and no back light 0.33A
Standby drain, scan with back light 0.427A
Lowest operational voltage 7.4V.
Power @ 10.5V=25W; 12.5V=25W;14V=25W.
Current drain at 12.5V/25W=5.81A.
Scan: 5 chan/sec.
External Speaker and cable provided. Extra speaker option.
Waterproof: Handset IPX7.
This is a �Rolls Royce� of VHFs but at a high price tag. The 240e is designed for the main unit to be installed behind a bulkhead. The control unit is somewhat like a telephone handset with a small in built speaker that can be used like a hand held VHF or as a telephone for privacy. The handset has an alphanumeric keyboard, greatly simplifying setup and use. Alternatively,  the audio can be piped to the supplied external speaker. There is also provision for connecting another speaker and another handset. Raymarine supplies many metres of cable and a foghorn capability is an extra.
Scan can be Normal, Priority or Memory and can also be forward or reverse.
The only think I did not like about the 240e was the fact that it consumed 0.33 amps when turned off as well as on standby. Admittedly, the excellent user manual does point this out and recommend fitting an external switch. I believe that users could well forget to turn off the external switch, resulting in a constant 8 amp hours drain per day.
There are three back light levels and 10 squelch levels. Unlike all the other radios tested, this one detected  when my GPS was running in simulator mode- a good safeguard. There is a Distance/Local switch. 
DSC: The DSC was easy to set up and use. Menus and controls were intuitive and easy to use. All DSC functionality is supported. 25 entry address book with 15 character names. The log holds up to 20 calls.
Raymarine 54E
RRP $553: Made in: China
Size (mm) 167Wx171Dx79H. Weight: 1486g.
Strengths: Separate DSC receiver, excellent DSC menus, crisp & comprehensive display, comprehensive scan modes, good audio, excellent manual, low volts warning.
Weaknesses: Back lighting varies across the screen.. The time does not increment when there is no GPS and time has been manually entered.
Knobs for power, volume, squelch & channel.
Standby drain, scan and no back light 0.181A
Standby drain, scan with back light 0.229A
Lowest operational voltage 7.3V
Power @ 10.5V=;22W 12.5V=25W;14V=25W.
Current drain at 12.5V/25W=5.55A.
Scan: 10chan/sec.
External Speaker: Yes and cable provided.
Waterproof: IPX-7.
This radio had just come onto the market when I performed the testing. The controls are well laid out and intuitive to use. Buttons are backlit on the radio and microphone. As sold in Australia, the radio can't access US or Canadian channels. However, if you are travelling to these countries, they can be quickly unlocked by the supplier. This is a more satisfactory arrangement than the majority of other radios which can (illegally) transmit on U/C channels in Australia. The large display would be better lit from two sides or provided with (more expensive) array back lighting. Still, it is useble and comes with 9 brightness and 9 contrast levels. The manual is excellent and even warns about antenna cable length and power connections.  The radio comes with protective front cover.
The DSC functionality was very easy to use and supported all functionality defined in the current DSC standards. Other radios use the main receiver to monitor the DSC channel 70, so they miss DSC calls if you are listening to another channel. Not this radio as it has a second receiver dedicated to DSC. I tested this and it works. There is a �phone book� so you can enter up to 20 other stations by name and MMSI which are used in transmit and receive. There is an internal log with space for 10 Distress Calls and 10 other calls.
BOX. Features at a glance
Model    RRP    Standby    Minimum    DSC    Power    Flush    Scan#    Sensitivity    Audio    My
drain    Volts        (12.5V)    mount    per Sec            Quality    choice

GME GX600    $325    0.151    8.0V    N    25W    O    8.5    =2        1    A
Icom IC-M302    $396    0.162    6.5V    Y    25W    O    11.4    5        2    3
Navman 7000    $299    0.170A    7.5V    N    25W    O    3.7    =2        =3    B
Navman 7200    $499    0.175A    7.6V    Y    25W    O    3.7    =2        =3    2
Oregon TM338    $299    0.145A    10.5V    Y    20W    O    5.2    7        =3    4
Raymarine 240e    $1,479    0.33A    7.4V    Y    25W    N/A    5    1        =3    5
Raymarine 54E    $553    0.181A    7.3V    Y    25W    O    10    6        =3    1

Prices were Recommended Retail at the time of publication deadlines and subject to change.
Y=Yes; O=option; N/A=Not Applicable.
# Scan speed is channels/sec for Normal Scan. Priority scan normally half this. Oregon does not have Normal Scan.
Figures- 1 is best.
"My choice" is my personal opinion based on my own cruising requirements of power drain, ease of use, performance, price and DSC capability. 1-5 for the DSC units. A (first) & B (second) for non-DSC.

BOX. Explanation of common features and terminology
MMSI. Maritime Mobile Service Identity. Unique number that identifies your vessel, next of kin and other contact details. Available in Australia from the Australian Maritime Safety Authority. An MMSI must be programmed before any of the DSC radios will work on DSC.
VMR. Volunteer Marine Radio organisation such as Coastal Patrol, Coast Guard Air Sea Rescue or similar.
The following terms were explained in last month's article comparing hand held VHF radios; if you missed this and want a copy send a SAE to CH, GPO Box 606, Sydney 2001.
Priority Channel.
Secondary Priority Channel or Call Channel.
U/C/I channel sets.
Dual Watch:
Tri Watch:
Scanning:
Priority Scanning:
Squelch.
BOX. How I tested
I used sophisticated laboratory equipment to test transmitter power output and receiver sensitivity.
As well as conducting laboratory tests, I transmitted from each unit to a base station and assessed audio quality aurally.
Scan speed was measured in the supported modes (normally Normal and Priority scans).
I tested power output with a range of battery voltages. In particular, I tested the minimum voltage at which the radio would still receive and produce 5W output and be intelligible to another station.  There were considerable differences between radios in this test.
Weights are my measurements with radio, microphone, mounting brackets and cables- a typical working configuration. Dimensions are from manufacturer handbooks and exclude projections such as knobs.
I did not test the water proof claims of manufacturers.
While DSC Testing, I ran each radio into a dummy load, in a shielded enclosure. I took a feed to another radio to decode the DSC output.

BOX. The power of DSC and a RED face
DSC will often get through when voice is unreadable in marginal conditions. This was reinforced during my testing by an incident that caused me some embarrassment. I was testing Distress Calls and inadvertently connected the output of the radio under test to my signal generator instead of the dummy load. I realised as soon as the Distress Call had been transmitted (this takes less than one second). I thought �No worries. The radio and signal generator are unharmed and I am a long way from anyone likely to pick up the very weak signal.� WRONG! A little while later, Coast Guard Solander (Botany Bay, Sydney- approximately 20NM away) was calling our boat (Pastime) on voice. They had recently installed DSC, picked up the distress call, contacted the Australian Maritime Safety Authority (AMSA) and obtained our vessel details. They'd also notified the Water Police. All in a few minutes! I re-assured them that the call had been an accident and the Water Police and AMSA were likewise reassured. The Coast Guard was pleased to have had a real test of their setup- something not previously possible. I had a very red face for a couple of days.

Author Box: David Kerr is a keen sailor who combines cruising with a love of electronic design, radio and several other hobbies. He and his wife Penny are setting