Electronics help

[Bad Habit]

I've been wrestling with an interference problem between my fish finder and VHF radio for a while now. I get a distinct "pinging" on a couple of channels on my radio when the ff is on. I have them hooked directly to sepperate batteries on opposite side of the boat. The antenna is on the same side as the radio and the transducer is on the same side as the FF. No where do any of the wires cross each other.There is added lengths of wire on both units to reach the batteries. Should these wires be shielded? Is there any way of telling if the wires that are used now are shielded?

This problem has been driving me crazy, Thanks for any advice!!!

[ray koziatek]

cant help on the fishfinder thingy interfering ,but i just replaced my whole moter (io) and the new moter has some distenct interference on ch 5,9,10,maybe some pocketsaver wearing ner i mean person could splane,,,,,,,,,ahem,, longline you there?????????

[LongLine]

What’s with this “pocket-saverâ€Â

[jimski2]

I have the same problem on channel 68.Shutting off the sonar mode on my combination fish finder / plotter stopped the noise. I use the other graph only.

[ray koziatek]

longline you were right it was the ignition,even got me a saver now i gotta get rid of those ink stains,turned off my engine and the noise want away now im having trouble hooking up and my arms get real tired from padaling my 22 ftr im gonna try a longer paddle cant get it over .002mph with current length

[L&M]

Ray your to much. LMAO

[Bad Habit]

longline, Thanks for the ideas. My antenna is the correct one for my radio. I even tried swapping it with another one and still had the problem. Both batteries are charging and are rooted through a perko battery switch. I'll try to turn the switch so both batteries aren't charging at the same time. It doesn't seem to make a difference if the ignition is on or off. The interference goes away if I turn the squelch up but then I can't receive any transmissions unless they're close. There is no difference if the radio and ff are hooked up to the same battery but I haven't tried reversing them. I guess I have a couple of things to try. Thanks again for the help.

[Bad Habit]

Does anyone know if it would make a difference if I used a deep cycle marine battery. Right now I'm using 2 regular cranking batteries because they are both being charged all the time.

[borderline 350]

Dear Bad Habit,

Deep cycle or Starting batteries will not make a difference in electronic noise levels. LOW WATER level in the battery cells will produce all kinds of interference! Also any cable or wire connection with small amounts of corrosion will set up high resistance and produce electronic noise.

The best tool is a good quality volt meter that you can read volts in .1 volt increments.

Method;

With the ignition key off, check the posts on the battery. You should get approx. 13 volts with no load (no equipment on). (If the battery was just charged)Turn the ignition key on and you should get at least 12.5 volts at the switch, gauge or equipment plug + side. What ever reading you get (at the equipment) should be no less then .5 volts lower then the battery voltage. If you get a 2 volt drop, the wire, terminals or fuse is suspect. I have seen corroded fuse ends cause problems. Bad grounds are highly suspect in most cases.

Small amounts off green salts in your electronics plugs will cause interference. Look very close at all terminations for traces of green salts.

If interference is still there, wrap EACH transducer cable, radio cable or fish finder cable for a ft. or two with aluminum foil near the equipment source. Also remember that most marine electronics work very poorly @ 10 volts and will even shut down! This is not good for your personal safety if your GPS quits in minimum visibilty!

Sincerely,

Jet Boat Bill

[jimski2]

Ignition system noise can be cleaned up with a capacitor. Go to an auto electronics shop and see if they can help you.