No ground plane antennas vs. mobile to base converter

[JimKovacks]

I'm setting up a portable RTK GNSS base transmitter on 450-470 Mhz. I can purchase two different types of NMO mount mobile antennas. Ground plane or no ground plane. The antenna will be on a survey tripod. I don't have a ground plane. 1) Would it be better to use a no ground plane antenna or better to use a ground plane antenna with a mobile to base converter like the Laird MBCN? 2) If I already have a no ground plane antenna, would it hurt to mount it on an MBCN?

 

[madrabbitt]

We have two different tripod antennas in service on low power solar temporary repeaters. One has a ground plane kit with tuned radials. The other has a ground plane disc made out of sheet metal, correctly sized for the repeater's frequency. Both use the same NMO antenna, which is a high gain whip.

The disc works better then the radials.

So, either make your own ground plane, or get the kit with the tuned radials, both would give you better performance then a no ground plane antenna.

Second question, no, it would not hurt to mount a no ground plane antenna on a setup with a ground plane. Its the same as if you put a NGP antenna on a metal roof and NMO.
It actually may have better performance anyway.

 

[mmckenna]

It depends on the specific antenna design.

A half wave antenna with out a ground plane will work similarly to a quarter wave with a ground plane. Radiation patterns will be slightly different, though.
A half wave with a ground plane will give you about 2.4dB gain, and a 5/8th's wave with a ground plane will give you 3dB of gain.

Ideally, a ground plane will improve performance, given everything else being equal.