The Jeep carriers both 6 and 2 meter horizontally polarized antennas for VHF SSB work. (It also has a Kenwood 742 tri-bander for 6M, 2M, & 70CM FM operation). The upper antenna is the 6 meter M2 6M SQLOOP, and is mounted on a 1 1/4" mast that is attached to the rear tire carrier. The antenna is about 18" above the roof line, however, it does not extend over the roof. I made my own version of the KB6KQ 2 meter mini-loop (the lower antenna) and located it about 10" below the 6 meter antenna. Amazingly, the two antennas do not interact with each other. I do have to turn the 2 meter amp off while running 6M SSB to prevent the amps T/R switching from going crazy. Although both antennas do a good job during mobile operations, the 2 meter antenna does better. The Icom 706 runs 100W output on 6 meters, and I added a little 100W amp (from Mirage) for 2 meter operations. I back the 706's output down to about 4W and it runs the amp at full output. Both antennas are fed with fairly short lengths of Belden RG-8X coax. (You can see the 9' HF whip antenna in the background.)
I have another pair of Norm's (KB6KQ) 2 meter mini-loops that I run stacked for rover work The upper loop is 60" above the roof and the lower loop is about 40" below it. They are connected with a 75 ohm phasing harness. After I built the loop you see in the above picture, I decided to pay Norm to build my next pair. The rear mounted loop stays on the Jeep all the time. The stacked pair only get put on for contest weekend and/or special trips where I really need the extra gain.
The M2 6M antenna is affected by moisture and somewhat by temperature. I have read postings from other owners that claim a significant shift in SWR occurs when the antenna gets wet, iced up, or snow covered. I find that I need to retune mine (that consists of turning the adjustment screw about 1/32 of a turn) once in the spring and again in the fall. This seems to compensate pretty well for the temperature extremes that exist in Phoenix. Due to the lack of rain in this area, I've not noticed a detuning problem due to this. Although I've not experienced it, I've been told that the KB6KQ 2M loop also is sensitive to rain.
With the start of the new solar cycle upon us, I am looking forward to doing some serious 6 meter SSB operating with this setup. I have caught a few e-skip openings with it so far and the results were quite pleasing. I can hardly wait for the F2 propagation to get going!
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