I'm a confused radio neophyte trying to compare two antennas using an ICOM
R8500...

For the most part both the AOR MA-500 mobile whip and Nil-Jon Super M base
seem to capture the same signals but the AOR generally has a much lower
"noise floor". That is to say, I can hear clearer voice via the AOR because
there is less background noise and scans "work" better because the squelch
can be set to a lower threshold. Same physical location and connection
cable using each antenna. I listen to a wide range of frequencies but have
noticed this phenomenon most in 750 - 950 MHz.

What causes this difference and how I can improve the Nil-Jon?


The AOR MA500 is a stainless steel 29 inch magnet mount mobile
scanner antenna covering 25 to 1300 MHz. Peak performance is
from approximately 100 to 400 MHz.

The NIL-JON Super M Base is a versatile VHF-UHF antenna providing
very high performance. The receive range is 25 to 1300 MHz. It may
be used for transceive applications at these frequencies: 144-148
and 435-465 MHz.