AM radio

bmagee · Dec 1, 2014

I recently installed a IH AM radio I had on my 460. With no tractor running, sounds great. with tractor running, I get humming or static based on the RPM's.

I also have another IH AM radio on my 300U with no problems at all.

I did some research and come across a "noise supressor" from radio shack?

Does anyone have any advice for me or how to fix?

I know its an AM and they are subject at best, but I like the look of the IH radio on these old tractors, plus on plow days, it gives some noise to listen to.

Thanks in Advance

Philip Doolittle · Dec 1, 2014

Static noise on your radio can be reduced by
putting a .1 microfarad capacitor on the +
(positive) terminal to tractor ground. Capacitor
should be rarted for at least 50 volts or higher
and plastic for weather reasons. That said "Radio
Shack" make noise reducers that also contain a
small inducter ( chock coil) which sells as a"
NOISE "eliminator. Either is not very expensive,
If you still have too much noise you may find that
a shielded wire for the 12 volt( maybe 6 volt)
power lead with the shield ONLY connected to
ground at the radio end. Hope this helps.

John T · Dec 1, 2014

To reduce noise and as a used tractor dealer, I saw all sorts of small condensors placed on the generators,,,,,,,,,placed at the battery,,,,,,,,,placed on the ignition, any of which might help some and likely didn't hurt. However, ignition noise from regular copper spark plug wires is another source of AM radio noise which suppressor plug wires might help reduce.

The Rat Shack devices likely have capacitance plus inductive choke coils which can indeed help and shouldn't hurt the situation, but if the noise is more ignition related it may still not completely solve the problem, give them a try, they're not that expensive and probably wont hurt, but you may have to look into plug wires and other issues.

John T Rusty as heck on Electronics, see what the other sparkies have to say

bmagee · Dec 1, 2014

Thanks on the plug wire advice. A friend here at work mentioned resistor sparkplugs as well. Along the same line as plug wires.

Jim Becker · Dec 1, 2014

Take the belt off your generator and try it with the engine running. That will tell you if the problem is generator or ignition induced. It may be both.

JDemaris · Dec 1, 2014

If it's ignition noise - you might need resistor
spark plugs or resistor ignition wires to cut down
on AM noise. That's why they are used on cars and
trucks. To cut down on radio frequency
interference and AM suffers much more then FM.

David G · Dec 1, 2014

A hum is usually an alternator or generator, add a condenser in the power to the radio, and on discharge of alternator or generator.

Janicholson · Dec 1, 2014

Magnetic suppression wires are fully conductive but cancel the RF noise. A bit expensive but often a great solution. (I don't like carbon wires) Jim

David G · Dec 1, 2014

Noise can come in the antenna, power supply or both. I really doubt it is ignition noise if it is a hum, that is usually a popping. A quick test would be to hook the radio to an external battery, that tells you how the noise is getting in.

bmagee · Dec 1, 2014

Thanks everyone for all the comments.

David G - add a condenser to power side of radio and other end to the discharge side i=of gen.? - correct?

Again, when tractor is NOT running, the radio is great, its only when the tractor is running you hear the humming. if you throttle up, the noise gets louder too.

David G · Dec 1, 2014

That is a good start, if it is a gen might want one on field also, John T could clarify.

AM radio

bmagee

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Philip Doolittle

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John T

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bmagee

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Jim Becker

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JDemaris

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David G

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Janicholson

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David G

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bmagee

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David G

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