Electric Motor Noises. GAHH!!
Hey Hey,
Just put in a Midland 1001Z, with a 5' baseloaded antenna on a magnet
mount on my truck (2001 Nissan). I get noise from pretty much all of my
electric motors in my vehicle. My AC Blower fan, windshield wipers and
windshield wiper pump are the ones I've noticed. The blower fan is the
worst. The pitch changes if i increase the fan speed, and the loudness
drowns out all but the strongest signals. What's odd is, I'm also
transmitting this whinng noise! If I turn off the blower fan, I can
receive and transmit just fine with very little noise.
If I disconnect the antenna, and connect just a wire with PL-259
connectors on both ends onto the radio, the noise exists as well, until
the connector is is tightened all the way on, then it goes away.
My radio has been wired directly onto both battery posts with lugs, and
is quite secure. I've tried putting in a noise filter inline (toroid
and capacitor) and also tried an RF choke (iron core with copper wound
around it), and nothing helped. I've tried the RF choike and noise
filter inline with the blower motor as well, and no difference.
I've tried running a ground to the magnet mount antenna base, to the
coax connector, to the radio, to no avail. I went to a clearing, and
adjusted my SWR when I initiallyh installed the radio, and it was
reading about 1.3 - 1.5. My car is parked about 5-10 feet from a power
line, and when I measure my SWR around there, it reads about 2-3. Not
sure if this is the power line, or if my SWR is really that bad,
haven't tested in a field again.
I'm pulling my hair out trying to figure this one out. We did cut a few
inches off the magnet mount coax, and reconnect another connector onto
the end. The closest guess I have is that maybe the shielding is wack
on the end of the cable? (Since a different cable without an antenna
doesn't exhibit the noise when it's tightened all the way on).
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