NMO Antenna Spacing

[Biggie_Z]

Hello all, I currently have a 5/8 wave 2m NMO antenna mounted on the roof of my Jeep connected to an ICOM IC-2300H 65W radio, I want to add another antenna to the roof for GMRS. I'll be using a Kenwood TK-805DH 40W radio. My question is how far apart should the antennas be without causing interference or damage to the radios? Any advice would be greatly appreciated, thank you.

 

[FFPM571]

All depends on how much room you have. I try to maintain 18-24 inch separation between radio antennas of any band, Due to space constraints it's not always possible.

 

[kayn1n32008]

As far as you can get them. Minimum to shoot for would be 18”.



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[mmckenna]

Yeah, it varies by a number of factors:
TX power.
RX filtering.
Antenna spacing.
Antenna gain.
Coaxial losses.
P.F.M.

Since damage can happen, and desense is a real issue, more spacing is better.
But it's difficult to give you an exact number. I've done 1/4 wave on the lowest frequency and that's worked for me.

Different radios will behave differently, so as with many of these types of questions, the answer is "depends".

 

[W5lz]

There are a lot of variables with that question. Very basically, as far apart as practical. Possible isn't always practical, and practical isn't always possible. You do the best that you can. This isn't limited to NMO type mounts, they all have the same limitations.

 

[a417]

I've seen some very close antenna spacing on some 'less-than-suitable' vehicles, which resulted in the application of lots and lots and lots of filtering (and loss...filters friggin' everywhere), so as mmckenna said...depends.

 

[cmdrwill]

Not to mention repairs to radios with burned out front ends in the receiver.