Noise in your receiver

Why little or no static in FM mode?

 

Static, from whatever cause, be it 'triboelectric', lightning, or unshielded sparkplugs is amplitude modulated, thus affecting both AM and SSB, which is just a sophisticated method of AM. FM is frequency modulation and an FM receiver is not affected by AM noise pulses.

 

Is it against Fcc regulations to use Fm mode on 11 meter?

 

Yes.

 

You've obviously not tried FM mode on the average 10 meter export.

 

Once on a General lee very little static, other time on a Galaxy 45mp with alot of static.

 

There have been numerous other occasions and as I remember correctly Fm just didnt seem to have as much static as Am, based on your post Volvo you apparently have had a different experience using Fm mode.

 

Not keeping anything a secret, just have to ask.

FM means Frequency Modulation where the frequency shifts back and forth with the audio introduced into the oscillator circuit (for simplicity). Some call it encoding, others call it modulating the frequency, but overall it is the same thing. AM is a signal that the audio is added to the fixed signal itself and has to be rectified out of the signal.

On the other end, the receive picks up the signal and it is decode what is called a discriminator, there are several type but that's not important. The discriminator process the signal because the audio is actually in the frequency shift opposed to rectifying it so the discriminator ignores all the noise that is also coming into the receiver to give near real life audio.

If you want a really in depth discussion about it, you can find tons of info on it, like the differences between discriminators or how to slope tune an AM radio to listen to FM.

But we've discussed static here a lot of times before, one solution is to have broken bungie cords hanging from the steps of the truck onto the ground, which is what i have with my little Plymouth in the barn to cure static. Others (I think Craig is the one who does this) uses graphite that is added to the oil in the hubs.

Other sources of static actually have something to do with the electrical system while many many trucks also have issues with "static" being created within the electrical/ECM systems and that is measurable through the use of an Ultrasonic receiver.