Signal to VHF speaker

[[2574]]

I know nothing of the electronic workings of loudspeakers and would appreciate some guidance. If I applied a 12v supply to a VHF speaker (such as this http://www.force4.co.uk/462/Vtronix-Deckwatch-VHF-Speaker.html) would it make a sound? I have a horn up the mast that works like this but that is clearly a mechanical device causing sound through vibration of parts, I suspect a VHF speaker is different?

TIA

Rob

 

[sunquest]

If you apply 12v you will hear a single click as the diaphragm is energised .

 

[lw395]

If you apply 12v you will hear a single click as the diaphragm is energised .

And possibly a 'bang' as it burns out?

 

[Beyondhelp]

more of a pop and fizzle... haha.

A speaker makes a sound by the frequency and amplitude of the incoming voltage. A constant voltage will produce no audible sound.

 

[[2574]]

Ah, thank you. I am enlightened.

 

[KellysEye]

To state the obvious if you want a loud speaker to work it needs to fed by the sound output of the radio not just a current. Our cockpit speaker was attached to spur from the main speaker.

 

[VicS]

Ah, thank you. I am enlightened.

I was tempted to ask where you were the day the rest of your class did "loudspeakers" but I put "national curriculum, loudspeaker" into Google and just got a load of links to Michael Gove!

Explain what you want to achieve and with luck someone will point you in the right direction.

 

[[2574]]

I was tempted to ask where you were the day the rest of your class did "loudspeakers" but I put "national curriculum, loudspeaker" into Google and just got a load of links to Michael Gove!

Explain what you want to achieve and with luck someone will point you in the right direction.

Thank you all for your forbearance; I can't answer where I was the day we did loudspeakers as it was about forty years ago.....

I have a fancy VHF radio (ICOM) that will output fog sound signals to a speaker; that's the easy bit and it works well. But I'd also like to connect a "button" to the speaker so that I can make other sound signals (Port/Starboard/Astern etc). Hence my schoolboy error idea of connecting a 12v feed and at the press of a button it makes a sound. It seems that is not possible, any bright ideas?

 

[lw395]

You need an audio oscillator of the correct frequency, to drive the speaker.

TBH, if it's loud enough for fog, I wouldn't want it in the cockpit pointing at me.

 

[Beyondhelp]

is the speaker placed outside? how loud do you want this to be, and are you hoping to use the same speak as the icom radio uses or is it an independent one?

 

[[2574]]

is the speaker placed outside? how loud do you want this to be, and are you hoping to use the same speak as the icom radio uses or is it an independent one?

Yes the speaker is outside and yes I was hoping to use the same speaker as the ICOM radio. As to loudness; well variable would be the ideal, but loud enough to be of use (that's not very scientific I know but I can't specify dB as I don't know).

 

[Jungle Jim]

How about a car horn from a breakers yard? Those work by connecting +12v dc via a button.

 

[planteater]

I looked at buying a VHF with an external hailer which contained a 30W amp and would relay speech from the mic or foghorn patterns programmed into the system

I've no idea how you select the patterns, though. What model is the VHF?

 

[[2574]]

What model is the VHF?

ICOM M606 (IIRC), not a current model, ten years old.

 

[Beyondhelp]

Cant find M606, can find M600. Would something that pulsed the fog horn function be suitable?

 

[VicS]

Thank you all for your forbearance; I can't answer where I was the day we did loudspeakers as it was about forty years ago.....

I am surprised you cannot remember things that recent, however we wont ask any embarrassing questions about what you might have been doing.

Also surprising you did not dust off the old text book before posting your question, but to save you the trouble here is a scan of the relevant page from your O level physics textbook.

Not a topic studied in great depth clearly!

 

[NOHOH]

There is a device called a Fogmate Horn Controller.........which....when connected to a horn.....will produce a limited range of pre-programmed signals for use in fog. I had to import mine from the USA...but that was a few years ago...... http://www.go2marine.com/product/92221F/fogmate-automated-horn-controller.html

 

[[2574]]

Cant find M606, can find M600. Would something that pulsed the fog horn function be suitable?

Sorry, M604 see here: http://www.islandwaterworld.com/browse.cfm/vhf-radio-ic-m604-w-dsc-fixed-mount-black/4,5990.html