Hope someone can help. Whilst sailing with the radio on I could hear a faint click noise thru the speakers and found that faster we sailed the number of clicks per second increased. So immediatly I thought of the log and sure as eggs when I turned off the log the clicking stopped. So does anyone know how to filter this noise out???
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Need a little more information
Which radio are you talking about? Marine VHF or SSB? Broadcast AM or FM? What brand is it? Have you noticed any other interference with other radio of TV signals? Does it show up as flashing in the TV picture? What kind of log? I am guessing you mean a knot-log. How did you turn off the log? Did that turn off anything else such as the depth sounder? Are you sure it was not the depth sounder or wind speed indicator causing this problem? Generally speaking, this may be a result of an electrical grounding problem (such as a ground loop) or it might be a signal coupling problem having to do with the way the wires are physically routed or shielded (or not). This might be an indication of a larger problem having to do with the grounding system on the boat. You will want to be careful not to permit (or else you should correct) inadvertant connections between the electrical and rf "grounds" and the boats bonding system. Practically speaking, you should check the wiring for breaks or bad or failing connections. Look carefully at crimped connections and wiggle them to see if the problem goes away or gets worse. Tighten up any screw terminals. Look for corrosion. You might be able to cure the problem by rerouting wires, shielding them, twisting them if they are not shielded, replacing them, or adding some filtering such as ferrite beads (also called toroids). You can put a clamp on toroid on most cables be they power or signal without much worry. A handheld AM transistor radio can be useful for detecting and physically isolating interference like this. Try tuning it around to see if it picks up the same interference. The term "ground loop" is a frequently misused term often tossed around by pony tailed guys on drugs as if they actually know something. It is often an issue in audio equipment and shows up on audio equipment as an unwanted hum. Your problem may not be properly called a ground loop but most of the same principles apply and then some. A boats grounding system has many more potential issues than a rock stars audio system. For more information than you ever wanted to know about ground loops - see the link
Which radio are you talking about? Marine VHF or SSB? Broadcast AM or FM? What brand is it? Have you noticed any other interference with other radio of TV signals? Does it show up as flashing in the TV picture? What kind of log? I am guessing you mean a knot-log. How did you turn off the log? Did that turn off anything else such as the depth sounder? Are you sure it was not the depth sounder or wind speed indicator causing this problem? Generally speaking, this may be a result of an electrical grounding problem (such as a ground loop) or it might be a signal coupling problem having to do with the way the wires are physically routed or shielded (or not). This might be an indication of a larger problem having to do with the grounding system on the boat. You will want to be careful not to permit (or else you should correct) inadvertant connections between the electrical and rf "grounds" and the boats bonding system. Practically speaking, you should check the wiring for breaks or bad or failing connections. Look carefully at crimped connections and wiggle them to see if the problem goes away or gets worse. Tighten up any screw terminals. Look for corrosion. You might be able to cure the problem by rerouting wires, shielding them, twisting them if they are not shielded, replacing them, or adding some filtering such as ferrite beads (also called toroids). You can put a clamp on toroid on most cables be they power or signal without much worry. A handheld AM transistor radio can be useful for detecting and physically isolating interference like this. Try tuning it around to see if it picks up the same interference. The term "ground loop" is a frequently misused term often tossed around by pony tailed guys on drugs as if they actually know something. It is often an issue in audio equipment and shows up on audio equipment as an unwanted hum. Your problem may not be properly called a ground loop but most of the same principles apply and then some. A boats grounding system has many more potential issues than a rock stars audio system. For more information than you ever wanted to know about ground loops - see the link
AM
The problem is related to the Navman Multi 3100 which has two thru hulls. One for depth, water temp etc and the other the paddle wheel for speed/log. My assumption is that the electrical pulse that the paddle wheel creates when spinning causes the electrical interference. All connection are secure and professionaly installed to the highest degree. The radio is located about 10' from the thru hull and about 4' from the 3100 head unit. Hope this helps?
The problem is related to the Navman Multi 3100 which has two thru hulls. One for depth, water temp etc and the other the paddle wheel for speed/log. My assumption is that the electrical pulse that the paddle wheel creates when spinning causes the electrical interference. All connection are secure and professionaly installed to the highest degree. The radio is located about 10' from the thru hull and about 4' from the 3100 head unit. Hope this helps?
Bundled wires?
The rotating of the speed paddle wheel simply clicks a voltage on and off with no appreciable current draw - assuming all is well in the control head. This should not broadcast a click to the antenna. Are any of the radio wires (power, speaker) bundled with the knot meter wires? Because I have a small 12 volt battery handy, I would try running the radio on an independent power source. This would indicate if the interference is coming through the power source or elsewhere. If it is the power, then simply adding a capacitor across the radio or knot meter breaker will probably solve the problem.
The rotating of the speed paddle wheel simply clicks a voltage on and off with no appreciable current draw - assuming all is well in the control head. This should not broadcast a click to the antenna. Are any of the radio wires (power, speaker) bundled with the knot meter wires? Because I have a small 12 volt battery handy, I would try running the radio on an independent power source. This would indicate if the interference is coming through the power source or elsewhere. If it is the power, then simply adding a capacitor across the radio or knot meter breaker will probably solve the problem.
Thanks Victor
No the wires for the speakers and power are no where near the Navman unit, its power supply or the leads from the thru hulls.
No the wires for the speakers and power are no where near the Navman unit, its power supply or the leads from the thru hulls.
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