Do I need a splitter?

[Petronella]

My friendly ham radio expert tells me that if I want to use my masthead VHF antenna to connect to both my DSC VHF 'ships' radio and my domestic 'car' radio I should do so by introducing an intelligent splitter device. This device would both match the signals correctly and prevent transmissions from the DSC set trashing my 'car' radio.

Is this your understanding too or can I in practice just use an antenna T-piece to provide a feed to both radios?

 

[boatmike]

No you can't use a T piece. Yes you do need a splitter. But personally I wouldn't. If thats all you want it for use a seperate aerial. If the splitter fails for any reason you will lose your VHF. Not worth the risk. Read up on other posts (start with three posts down) dealing with AIS

 

[st599]

No you can't use a T-piece, it won't impedance match and, more importantly, it will put at least 1/2 the Tx Power across the car radio PA.

Result = smoke.

Why would you want to diplex these two signals? You're putting another point of failure in a safety-critical circuit.

 

[William_H]

By far the better arrangement is to fit a pushpit mounted VHF antenna which is normally used to drive the car radio but in an emergency can be connected to the DSC VHF radio.
However if that is too much cost/troubel a car radio will work well on a piece of wire pushed into the antenna socket and run horizontally inside the cabin for about 1 metre. ie along a shelf or inside the lining assuming it is a fibreglass boat.
Don't even consider a splitter from the main VHF antenna. olewill

 

[Petronella]

Well that's pretty conclusive. We won't be doing that then! Thanks for your comments and explanations.