2 meter SSB mobile presents some interesting design quirks after leaving the familiar world of vertical polarization in the mobile environment. What is left of the '92 explorer (187k miles), sports an M2 two meter square halo for omni-directional horizontal polarization.

Shadowed by its counterpart on the tower, the M2 does a respectable job mounted only 36 inches above a metal surface and approximately 9 1/2 feet above the ground.

QRM from the vehicle is not a problem on VHF. Fuel pump, computer, and ignition noise are terrible on HF and at its present stage of life, delousing the vehicle would not be worth the labor.

Wind tests on the antenna were made before the radio was installed. The springy 1/2 inch x 36 inch mast holds the antenna steady at 75 mph. A small mirror was held out of the driver's side window so that the antenna could be seen. It was at first thought that severe oscillation would be experienced because of the unpredictable aerodynamics. The antenna is stable in the wind and does not bend back very far, possibly due to the trailing elements resistance to any position other that horizontal.

The only thing noticed while driving was the increase in wind noise transmitted through the roof about the same a putting a ladder on the luggage carrier. The feed point was waterproofed with silicone tape and then wrapped with scotch 33, white in this case. As an added bonus, the drivers of oncoming vehicles occasionally give you the "a ufo landed on your roof" look. My wife transparently accepts it after 33 years of desensitization to ham radio oddities.

To solve the problem of bank drive-thru's a means was devised to fold the antenna over thanks to a machinist with too much time on his hands at work. First the carbon composite sleeve is slipped up...

Because of the 45 degree cut, the antenna can only tilt forward. This takes stress off of the mount when driving.

Now the antenna is collapsed, it just makes it through the garage door and is fine for fast food windows. The alternative would be to remove the home made 4-magnet mount from the roof which requires a considerable amount of effort, as well as the concern of the roof separating from the vehicle.

In this view the spread of the gap in the back of the antenna is clearly visible, the was done to set the resonant point on the band (144.1 to 144.3). The instructions alluded to trimming the ends by 1/8 inch but this would be a permanent adjustment and the antenna may be used in a different location in the future. By spreading the ends from their native 2 1/2 inches to 3 1/2 inches,  the resonant point fell in the correct area, the stub was then adjusted for minimum SWR, in this case 1.1:1

The equipment rides in a convenient operating location and is easily installed and removed (daily). 30 amps fused is available just behind the rig on a lexan binding post panel under the dash. The 706 mk2g does a nice job and the mirage pumps the signal up to around 120 watts. The mfj meter is not kept inline because of possible losses, it is used for occasional checks. A better meter could be used but did not fit well on the mount. The equipment rack is also made from lexan because of it's ease in fabrication.

The first on air, mobile, test was made on June 24, 2004 with N9BXX Al, who lives about 40 miles north of my QTH. We talked for about an hour while in-motion. The results were good overall and at this range we had a reliable connection. On June 25 a mobile test was made with K9VQR Archie, who lives near LaCrosse about 180 miles from here. Archie has a high-gain VHF array and is in a high location. At no time during the 45 minutes we were talking was there a gap in communication, most of the time Archie was received at an S1 to S2. At times his signal was as high as S6 and other times there was no S meter reading. There was no band enhancement observed. Normal QSB and flutter was noted as well as changing local conditions of the mobile.