Fixed VHF wont broadcast on hi power

[MikeJ2]

I have a new Raymarine fixed VHF that wont broadcast on hi power. The battery indicator comes on, which apparently means voltage is dropping below 10.5v, which isn't the case. Should I put this down as a faulty unit? Has anyone else experienced this with a Raymarine unit? Thanks, Mike.

 

[mainshiptom]

Connect a multimeter on supply to vhf while transmitting and watch the voltage drop?

Might be the wires of a faulty connection?

 

[jjc]

have you used heavy cables to connect it as they draw a lot of power on 25W. all the symptoms you describe look as if your cables are introducing a volt drop.

John

 

[duncan]

I had it on a Simrad, followed by it not even switching on! Run the test tom suggested as I found that I had 12.7v at the leads on a multimeter but when I reconnected the unit and tried under load the voltage had dropped to under 9!
Traced it back to a fault in the wiring which when fixed solved it.

 

[brianrunyard]

Check the voltage at the set whilst transmitting, probably got a bad connection causing a volt drop.

 

[Oldhand]

Could be your antenna installation is faulty and the impedence is low causing the transmitter to try and draw too much current. In this case the voltage drop may be internal to the unit. I would suggest you have your antenna installation tested as further attempts to transmit on full power could damage the VHF.

 

[brianrunyard]

Bad connection, dirty fuse holder or fuse, negative not from true 0volts.
check for voltage drop along supply by measuring the voltage between the two ends of the positive lead whilst pressing the transmit button, repeat for the negative lead.
Or eliminate the wiring by connecting the radio directly to the battery, via a fuse of coarse.