VHF Radio Crashes on 25 Watt Setting

[arcadiahunter28]

The VHF radio on my boat works both at 25W and 1W. But our marina has the exact same radio and whenever they are set to 25W the radio crashes and reboots. They can hear incoming transmissions, but can never reply when set to 25W. Anybody know why that might happen?

 

[arcadiahunter28]

BTW, works fine at 1W but the radio automatically defaults to 25W whenever it’s powered on.

 

[Davidasailor26]

Maybe voltage drop in the supply line when the current draw goes up? Check all connections and try to test the voltage at the radio connector with the radio off, on, transmitting at 1W, and transmitting at 25W.

 

[arcadiahunter28]

We disconnected the antenna and then tried to transmit and it didn’t crash. Does that confirm that the issue is with the antenna or the antenna connection?

 

[Davidasailor26]

Trying to transmit without an antenna is generally not advisable as it could damage the radio. The radio might have some self-protection circuitry that kicked in and just prevented any transmission.

 

[JBP-PA]

Put a voltmeter on it or give it a different power supply. The power required to transmit at 25W can be a lot. If the wires are too small or if there is a marginal connection, that can cause it to crash.

 

[arcadiahunter28]

It has an AC converter that looks like it might only push out 3 W. Could that be causing the problem? Maybe we need a different AC converter?

 

[JBP-PA]

It has an AC converter that looks like it might only push out 3 W. Could that be causing the problem? Maybe we need a different AC converter?

Yep. It will draw around 6A when transmitting at 25W.

 

[arcadiahunter28]

Ok - sounds like that’s the issue. Our converter is from Radio Shack . Can you point me to a converter that’d work for our radio?

 

[arcadiahunter28]

Something like this? Idealy 12VDC 8.33AMP 100Watts LED Driver,Waterproof IP67 LED Power Supply Low Voltage Transformer Adapter,100V-260V AC to 12V DC Output for Any 12VDC LED Lighting Amazon.com

 

[Davidasailor26]

I’ve never tried to use an AC adapter for a VHF, so I can’t say for sure. But for $3 extra I’d probably lean towards the 150W model of what you sent.

 

[JBP-PA]

That would probably work. As David said, you want to have a big safety margin, especially with cheap stuff. They often fail if you push them to the limits.
One problem you might encounter is electrical noise since that supply is intended for LEDs and not radios. If so you might have to shell out for a proper power supply for radios such as this one.

Amazon.com

 

[jviss]

We disconnected the antenna and then tried to transmit

Bad idea. Will blow the output stage on most radios.