VHF Hum

[Salty Feather]

I just had a new TTop installed and completed the installation of the electronics today. Everything was working great until I wiring up two new 55watt halogen deck lights. The lights work great but the problem is when I have my VHF on and then switch on the deck lights I get nothing but a hum from the radio. The radio and lights are wired out from a bus in the new electronics box on the top. The bus is supplied by a pair of 16 guage wires that are shielded and jacketed.<br />Any ideas ?

 

[Dunaruna]

Re: VHF Hum

Ground. Check ALL your grounds. Give them all a good clean.<br /><br />What do you mean by 'electronic box'? Is it just a ground buss in a plastic box? Was the motor running during the hum?<br /><br />Aldo

 

[Salty Feather]

Re: VHF Hum

The electronics box is just a fiberglass box with the radio mounted in it. Inside I mounted a buss with one positive lead and one negative lead to the center console below where is is connected to the pos and neg from the battery. Also connected to the buss are the anchor light,the LED dome light, the deck lights and the VHF.I have not run the motor yet.<br />The radio sounds perfect with every other electronics and lights on, it's just when the halogen deck lights are switched on.

 

[Dunaruna]

Re: VHF Hum

Woops, forgot to ask - glass or alloy boat?<br /><br />I asked about the motor running to discount the possibility of an alternator hum. It's obviously not an alternator hum.<br /><br />I'm trying to picture your wiring - you can't connect a pos and a neg to one buss bar, that would be a dead short. <br /><br />Your wiring should look something like this - all the grounds for every accessory running through a buss bar and every individual positive running through a fused switch. <br /><br />Aldo

 

[waterone1@aol.com]

Re: VHF Hum

Sounds like your voltage to the radio is dropping due to overloading the 16 gauge wire. Two 55 watt halogens are drawing just under 10 amps....with nothing else on ! You should be using #12 for this installation.

 

[Dunaruna]

Re: VHF Hum

Good pick up, I didn't see the 16guage reference. That'll teach me to read slower.

 

[Boatist]

Re: VHF Hum

I agree he is way over loaded. My VHF has a 12 guage wire just for the radio. VHF is a important saftey iteam and should my motor die and battery get run down some I still want good power to the VFH. GPS, Loran C, and depthfinder I also want on their own power. All the lights except navigation light can be on one wire but with 110 watts or 9.2 amps should have at least 14 guage and 12 would be even better.

 

[18rabbit]

Re: VHF Hum

Depending on how far it is from your battery(s) to the power bus, and what you have hanging off that bus, you are probably looking at conductors in the AWG single digits.

 

[18rabbit]

Re: VHF Hum

Something else that I just remembered…an FYI: Halogen lamps don’t like voltage above about 13.7-13.8vdc. They will light up just fine above that and won’t complain but their useful life is cut dramatically short. It’s something to keep in mind if operating those lamps while underway with an unregulated alternator or if sitting dockside on a battery charger putting out 14.2vdc or whatever. Anyway, you get the idea…