Arranging your Antennas-How do you it?

[Rob Wadsworth]

I have a cell phone antenna, a 10/12 meter antenna, and a 2m/70cm antenna.
I see vehicles that look like porcupines running around during chases, which I'm sure it cannot be helped. Who cares what it all looks like anyway - so long as it works - right? The point is - achieving harmonious function without any conflicts between radios when operating...

But antennas must somehow all function in harmony when on a chase. Some may well have passive antennas for your scanner. As well as having antennas that transmit and receive. The distance, location, and priority of these antennas must not encumber the next one from working correctly.

If it all sounds like juggling - it is. But how does one choose where each antenna should go? Wavelengths of each antenna are different and can interact with another depending upon their respective spacing. Can it change the SWR adversely?
Probably.
So what method and its rationale are best?


Thoughts from Hams and ex-radio operators are welcome.
Any link that can be provided here will be gratefully appreciated.

 

[Benjamin Rock]

I have 4 antennas(anntenae?) on the car. My car is a station wagon though so there is more roof space than smaller cars. Anyways, front to back in a line. The tallest is a CB the second is 2m and the third is multi-band for scanner. Then there is a small dual-band all the way up front ahead of the luggage rack. My SWR are all under 1.2 and I have no adverse effects on the other radios. the spacing is about 18 inches or so. Now like I said, this is a station wagon so it's long and the roof slopes slightly as you run towards the back. Works though.

 

[Ben Holcomb]

The further spacing the better, but other than that, I just slap mine on the roof. They all perform well enough for my needs.

 

[Jason Foster]

The 10/12 meter antenna should be toward the middle of the roof or truck, to allow for the greatest ground plain (if using an antenna requiring a ground plain). 2 meters could do OK on a truck, especially at 5/8 wave. Cell phone and other high frequency antennas can pretty much go anywhere, but higher the better, so try to keep it to the roof.

Most of the time, if the antennas are spaced enough apart, it won't affect the SWR to much (be sure to check it with a SWR meter). The biggest issue is that nearby antennas will possible affect the radiation pattern, but again not to bad with proper distances. The biggest hurdle is the 10/12 meter. That is why many ham sexy set-ups occur...because then folks go with antennas with their own built in ground plain elements to them, but which gets to be a little outlandish.

Another possible solution, if you don't plan on using 10/12 meters while in chase mode, is to have an antenna you only put up when in use....something say mounted on a hitch, and stored in the trunk when not in use.