Splitter

[Emmet]

Hi,
Has anyone heard of a splitter which could be used to give prioity to one signal over the other? Im thinking of the external speaker connected to a cd player and VHF. I would like the vhf broadcast to interupt the music signal to the speaker.

Any help is much appreciated,
Cheers

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[bedouin]

I think a similar question was asked a few months ago - try using search to see if there were any useful replies.

In theory this is not too difficult to achieve - you could probably build one for about £10-£20, but there are practical problems, for example the speakers attached to a VHF radio are unlikely to be particularly suitable for music and vice verse.

Alternatives are to use an external amp, which can have a priority input (these you can get), or go for a set up with separate speakers but where the VHF mutes the radio (I think some car sets do this for use with mobile phones)

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[MainlySteam]

As I understand your question you want the music to automatically quiet when the vhf operates into the same speakers rather than by manual use of a switch.

I know of no cheap off the shelf way of doing that suitable for small vessels, but it is possible for bigger boats with room and power resources. It may be possible to find something similar and cheaper for small vessels.

For bigger vessels it is common to have the public address input automatically quiet the music/tv or whatever audio is playing and to do that we use the systems which are commonly available for business music systems (your store type systems, which play background music but a voice announcement automatically quiets the music - you can get very good quality systems, not all are just aimed at muzak). The music/tv audio/PA audio are all inputs to a mixer amplifier amplifier which allows prioritising of inputs. If I recall correctly the system being used on some current boats (Toa mixer amplifiers, from memory - they have an internet site) have 24 v power option (and maybe 12v). The VHF could obviously be the priority input in such a system (but would not be allowed in a non volunteerily VHF equipped vessel) but you would need to convert the speaker output level to a low level signal for input to the mixer amplifier so quite some trouble involved.

If you have a small boat, it may be that a small mixer amplifier with just 2 inputs could be found by searching the internet - you need to look for "mixer amplifier with paging priority input".

If you have a big boat, PM me before end of Friday and I will fish out more information from on board some so fitted boats next week.

John

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[cliff]

Not sure if this is what you are looking for but it is automatic, 4 inputs, 12v etc
<A target="_blank" HREF=http://www.maplin.co.uk/> click here and search for item VV97F </A>

Maybe more than what you are looking for. /forums/images/icons/wink.gif

Failing that talk to some of the chappies in your local Maplin store. Don't know if they are the same as those in minebut I have found them helpful and a few even "nerdy" and up for a challange. there may even be an IC available to do your job - does not hurt to ask the question.

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[Emmet]

Thanks for the advice, I was hoping for just a nice small cheap splitter but who khows, Ill get maplin to check it out, as you say there are many nerdy folk who would love a challenge.

And thanks John, however its not that important was just looking to see if there was a simple solution.



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[MainlySteam]

If you find anything simple that automatically mutes the stereo let me know /forums/images/icons/smile.gif.

A possible direction that a nerdy type might come up with a clever solution with is using a car stereo that has a cell phone mute input on it. These work by having a 12 v signal from the phone car kit to mute the stereo (I think some car kits put out 12 v mute and others are 0 v mute). It has occured to me in the past that maybe one could use something to create the 12 v signal when there is signal on the VHF speaker leads in order to automatically mute such a stereo. Sounds like a get out the soldering iron and some components to make something up job to me, but one never knows.

John

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[Emmet]

I will let you all know as soon as I find something.
Im studying electronic engineering and have been thinking about this idea for a while, just wanted to check if there was already an existing solution.
After my exams I'll try and come up with something.

Thanks for the help

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[Colinl]

In my car I have a hands free phone system installed and when the phone rings it mutes the radio sound, so there must be some similar device for the vhf

Colin

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