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ICOM 2100H Mobile 2 Meter Radio Interference Problem

Posted: Wed Jun 18, 2003 1:18 am
by F1118
Anyone having a problem with alternator interference with the Icom 2100H?

alternator wine in Icom

Posted: Tue Apr 06, 2004 7:05 pm
by Radioactive
What you should check first is the alternator. Make sure you do not have
a Stator diode out. It will still charge (maybe high speed or low speed) but
one might be out. Anyway then make sure you are going direct to the
battery. It would be good if you use a 30-amp relay inline with the hot side
so not to allow a voltage spike while you are starting the car.
If that does not work then you need to check the large electrolytic cap near
the power cord inside the radio. I've replace many of them that get spikes
during startup. Make sure the radio is grounded. Not just through the
negative line but to the frame of the car. Hope that helps you.

Robert

Re: alternator wine in Icom

Posted: Tue Apr 06, 2004 10:12 pm
by jim202
[quote="Radioactive"]What you should check first is the alternator. Make sure you do not have
a Stator diode out. It will still charge (maybe high speed or low speed) but
one might be out. Robert[/quote]

To add to what Robert has indicated, if you have a digital volt meter, try looking at the 12 volt line going to the radio with the meter set to a low AC voltage setting. You shouldn't see much of anything for AC voltage. I am talking on the order of 0.1 to 0.3 volts.

Another problem is that if your battery is getting OLD, it will not filter out any noise in the electrical system. I have seen a 2 year old battery have this problem. If the battery is 3 years or older, your on borrowed time. Get the battery replaced before going any further.

I had an Icom that would have a whine on TX. Checked out my alternator and then the battery. Replaced the battery and the problem went away.

As a car battery ages, the internal resistance goes up. When the resistance gets high enough, the starter causes the battery voltage to go way down when starting the engine. The first indications are the car clock starts to loose time or gets reset when you start the car or truck.

Jim

What year and make of car?

Posted: Tue Aug 24, 2004 9:03 pm
by Raymond156
What is the year and model of car?

I have a 2100H in a 2000 Ranger...

Posted: Wed Sep 14, 2005 8:31 pm
by SDenny61
The only way I could get rid of the RF was to put an in-line noise limiter on the +12V feed line. I had the alternator checked twice by 2 different shops and had the battery replaced and stil had the noise. They are available from RS for about $20.00 or so. Hope you get it worked out! Steve D KD8BIW