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Author Topic:   VHF Marine Band Multi-Band Radios
jimh posted 07-06-2014 03:37 PM ET (US)   Profile for jimh   Send Email to jimh  
There are several hand-held radios that provide a Marine Band VHF Marine radio and transceivers or receivers for other bands. The usual combinations are to add to the VHF Marine Band a Family Radio Service (FRS) transceiver, an FM-Broadcast Band receiver, an AM-Broadcast Band Receiver, and an Aviation or Aircraft Band receiver.

A brief summary of the frequencies, modes, power levels, and channelization for those five bands follows>

VHF Marine Band
The VHF Marine Band is allocated 156 to 162-MHz, operates with frequency modulation (for voice), and use 25-Watts maximum for fixed transmitters and 10-Watts maximum for hand-held transmitters (see http://continuouswave.com/ubb/Forum6/HTML/003567.html ). The service is channelized into more than 50 channels, including simplex and split receive-transmit pairs. (See http://continuouswave.com/whaler/reference/VHF_MarineBandChannels.html ).

Family Radio Band
The Family Radio Service band is allocated at 462-MHz and 467-MHz, operates with frquency modulation, and uses 0.5-watts maximum for all transmitters. The service is channelized into 14-channels.

FM-Broadcast Band
The FM Broadcast band is a one-way, broadcast service allocated 88 to 108-MHz, uses frequency modulation, and stations may operate at powers of 100,000-Watts or more. The service is channelized in the USA with 200-kHz spacing and only channels with odd decimal parts are used, i.e. 97.1 but not 97.0 or 97.2-Mhz.

AM-Broadcast Bandp
The AM Broadcast band is a one-way, broadcast service allocated 530 to 1690-kHz, amplitude modulation is used, and staions may operate at powers of up to 50,000-Watts or more. The service is channelized in the USA with 10-kHz spacing

Aircraft Band
The Aircraft band is a two-way service allocated 108 to 137-MHz. uses amplitude modulation, and stations may operate with powers of 25-watts. The service is channelized with hundreds of channels.

jimh posted 07-06-2014 03:57 PM ET (US)     Profile for jimh  Send Email to jimh     
The typical multi-band radio with VHF Marine Band features will usually have a transmit capability on the Marine Band and FRS Band. The broadcast bands and aircraft bands will be receive only.

I am interesting in compiling a list of hand-held (or fixed mount) radios that are VHF Marine Band and multi-band radios. I can start the list with these:

West Marine VHF 250 (no longer made)

Standard Horizon HX470 (no longer made) (This radio also had Multi-Use Radio Service MURS capability.)

Standard Horizon HX471S (not sure if still in production)

Are there any hand-held radios in current production that combine a VHF Marine Band radio with a Family Radio Service radio?

Chuck Tribolet posted 07-06-2014 08:38 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
One important note is that if the radio can transmit in the
FRS band, it cannot have a removable antenna, which means you
cannot use your boat's antenna to get better range in the
marine VHF band.

My hand-held is a Standard Horizon HX470S. It's a decent
Marine VHF band radio, but a mediocre at best FRS radio. At
the one dive site where we need ship-to-spouse communications,
we bring Motorola FRS radios. It will transmit on the MURS
band, though I've no idea how good it is because I never found
anyone to talk to on that band.


Chuck

jimh posted 07-07-2014 03:30 PM ET (US)     Profile for jimh  Send Email to jimh     
The MURS band is better suited to combining with a VHF Marine Band radio because MURS is allocated on channels just below the Marine Band, from 151 to 154-MHz. Also MURS is a 2-watt power limit.

That means MURS might be able to transmit on an antenna tuned for the VHF Marine Band, assuming the antenna was not a really sharply tuned, narrow band antenna, without having the VSWR be too high.

The 2-Watt power is 6-dB more power than FRS radios.

On the other hand, a UHF handheld radio probably has a more efficient antenna than a VHF handheld.

MURS is mentioned as being used by some government agencies. I don't know if they are on the same channels as the public. Also, the feds may be using encrypted transmissions on MURS channels. See

http://continuouswave.com/ubb/Forum6/HTML/003029.html

jimh posted 07-07-2014 03:39 PM ET (US)     Profile for jimh  Send Email to jimh     
It appears that MURS radios can be used with an external antenna to increase range, at least that is the inference I get from this advertisement:

http://shop.murs-radio.com/MURS-Base-M538-BS.htm

and confirmed by the FCC description: http://www.fcc.gov/encyclopedia/multi-use-radio-service-murs-0

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