Scanner antenna placement help please

[Railfan74]

I have a new to me 2012 Jeep Grand Cherokee. Looking for ideas on where to mount a antenna. Was thinking a lip mount on driver side front fender. I have a taller antenna that was given to me. If I recall correctly, it’s about 30 inches long. Also have the smaller length ones. The roof mount radio antenna is broken, replacing it would be around $225. Would it make sense to use that hole to mount a NMO? I usually don’t listen to AM/FM radio as I normally have the scanner on.

 

[Railfan74]

I posted on another thread, but made my mind up on the mounting location. Since the AM/FM antenna is broken off in the base of the shark fin roof mount, replacement cost is estimated at $225 for the part. I don’t normally listen to the radio as I am listening to the scanner. Not worried about losing Sirius reception as it’s spotty at best. Removal of the shark fin and placing a NMO mount through the hole seems logical. It doesn’t leak with the broken antenna in it now. This would also allow me to charge my antenna length as needed.

 

[IC-R20]

You can also get stealth antennas that look exactly the same as the shark fin, though a little bigger. They make for VHF, UHF, and 700/800/900 bands.

 

[mmckenna]

I posted on another thread, but made my mind up on the mounting location. Since the AM/FM antenna is broken off in the base of the shark fin roof mount, replacement cost is estimated at $225 for the part. I don’t normally listen to the radio as I am listening to the scanner. Not worried about losing Sirius reception as it’s spotty at best. Removal of the shark fin and placing a NMO mount through the hole seems logical. It doesn’t leak with the broken antenna in it now. This would also allow me to charge my antenna length as needed.

Are you sure the existing hole is 3/4" round? Some of those AM/FM/Satellite antennas use different size/shape mounts that may not be compatible with the NMO mount. What I can find on line shows a square hole.
Personally, I wouldn't want to mess with trying to install a round antenna mount into a square hole.

 

[Railfan74]

I have a 3/4 chassis punch. So that should work for making the hole round as long as it’s not too big of a square. I just got the NMO mount as the other one I had was worn out due to rubbing issues. I’m hoping that mounting the antenna there won’t affect the ground plane too much, as it’s not centered but more rearward.

 

[mmckenna]

I have a 3/4 chassis punch. So that should work for making the hole round as long as it’s not too big of a square. I just got the NMO mount as the other one I had was worn out due to rubbing issues. I’m hoping that mounting the antenna there won’t affect the ground plane too much, as it’s not centered but more rearward.

Ideally you want 1/4 wavelength in all directions under the antenna on your lowest operating frequency. It'll work with less, but there will be some slight degradation.