Radio noise

[evilnev]

g`day ,my 27mhz radio in my boat makes a humming noise that comes through the speaker when it is turned off,i have removed it from the boat & powered it up in my garage & it does not make the noise ,can any body shed any light on this problem for me?
thanks

[Online store]

Probaly picking up electrical noise from wiring loom, sounders etc.

[punchanello]

g`day ,my 27mhz radio in my boat makes a humming noise that comes through the speaker when it is turned off,i have removed it from the boat & powered it up in my garage & it does not make the noise ,can any body shed any light on this problem for me?
thanks

Bad earthing I think. At least, that's what it is when the same thing happens in a car. Either fix the earthing problem or you can buy a supressor which might work.

[reddog2]

Got a leccie, inverter, or sounder near by or check you earthing :confused:

[evilnev]

thanks for the replies,i should have mentioned,that nothing is running at all or plugged in when it happens,my boat is all packed up with the cover on,i think the bad earth might be the cause ,how is this fixed?

[reddog2]

thanks for the replies,i should have mentioned,that nothing is running at all or plugged in when it happens,my boat is all packed up with the cover on,i think the bad earth might be the cause ,how is this fixed?

Is your earth cable grounded to your battery (doesn't matter which terminal in most cases) but some are negative ground too, or is it grounded to a grounding block..:confused:;)

if its connected to either above, check terminal for dirt, acid etc or check over wire to see if there is no cracks etc, and if have a main earth wire check that too..
salt and aluminum boats don't mix well get electrolysis and corrosion;)

PS If u ever have problems with radio whilst on this is a good read: http://www.animations.physics.unsw.edu.au/jw/EMspectrum.html

Cheers reddog2

[evilnev]

i just had a look at all the wiring,it is grounded to the battery,but the radio wiring has been soldered in with all the other wires from my switch panel,so what i`m gunna do is just get a new loom for the radio itself & see how that goes,thanks for the info.

[reddog2]

i just had a look at all the wiring,it is grounded to the battery,but the radio wiring has been soldered in with all the other wires from my switch panel,so what i`m gunna do is just get a new loom for the radio itself & see how that goes,thanks for the info.

forgot to say that, also if there is any wiring in contact with the earth wire it may earth it back to radio or in sum circumstances back through into your hull :cool:;)

[evilnev]

now that i got a new separate loom ,it seem to have fixed the problem

[reddog2]

nice ;);) woulda been that the it was earthing out through the old one :D:D;)