VHS, overriding FM on a boat?

Question

I have a boat, and like to listen to music when sailing. I also have a VHf Marine radio that receives distress calls, coast guard announcements and the like.

I would LIKE the VHf to cut out the Music when an announcement comes through.

Is there some piece of hardware that will allow me to do this?

Answer 1

Yes, you can usually accomplish your request by using only one or two (at the most) wires as long as you have equipment that's less than about 10 years old - and even older with some equipment.

As was mentioned before, most modern music radios will have a "mute" input that's available at the rear wiring socket on the back of the unit. These "mute" inputs are for use with two-ways or cellular equipment and work by putting a ground (-) on the "mute" terminal to kill the audio from the entertainment equipment.

Almost all two-way equipment (of any band or type) is also equipped with an output pin (in a rear "options" connector) that provides a switched ground when the receiver's squelch is opened by an incoming signal. Unfortunately, many different two-way radio brands may call this output by a number of names that may be "squelch switch Lo", "channel busy Indicator", "mute output", and a few other names.

If you don't have an options output table for your marine radio but have an inexpensive electronic multimeter, you can set it to measure 12VDC and hunt for this mute ouput on the two-way's options socket. You can simply ground its black lead to the two-way's metal chassis or ground wire, then use the meter's red (+) lead to insert into each hole of the two-way's options plug. Check each pin of the options plug that normally shows +12 volts on the meter, then open the squelch on your two-way. When you find the right pin, you'll have +12 present when the radio is squelched quiet, and the voltage will drop to zero when the radio is unsquelched.

You simply run a single wire straight from the two-way's "mute output" pin to the "mute" pin on the entertainment equipment. The second wire would only be needed to ground the metal chassis of the two pieces of equipment together if the single wire doesn't work well.

Even if there are no mute inputs to be found on the entertainment radio, an electronics technician (at any local radio shop) can easily rig up a transistor switch to do the job if you take in both the two-way and music radio together.

Answer 2

Most modern car stereo radios have a mute lead that cuts audio output when like receiving a car cellular phone call. It must not be impossible to use this to solve your problem with the VHF; have a look at the VHF wiring, or have it done by your local VHF supplier.

Answer 3

Generally it is necessary to use a safety device n the aerial that allows both to come in. Speakers in the cockpit and a VHF speaker in the cockpit also would help. You can mess up your VHF if you are using the same aerial without this device. Call West Marine adviser, an 800 number, for the name of the device.

Answer 4

Not that i know of??Turn it up>

Answer 5

NO