Batboard

Looking to install nmo mounts in roof of fiberglass truck cap. VHF UHF 800. In old days (just 5 yrs ago) of ems I remember the cars (fiberglass roof to the Ford E250 conversions) had roof mounted VHF Lo and UHF antennas however used a metal ground plane kit to add to the nmo mounts and antennas. Anyone know of a commercially available answer to this to apply to the roof of a truck cap or something to do the job without noticable difference to the vehicle?

Most of the commercially available kits i've seen are just 6" cutouts of sheetmetal, designed to be glued to the roof and then drilled thru and have the antenna mounted thru. Got someone with a jigsaw and a piece of 20ga sheetmetal and you are in business.

Ask a print shop, newspaper, or lithographer for their old aluminum plates. Generally 24" by 36" or larger to print two pages of newsprint. Easily trimmed to fit contours of vehicle roof. Spray on carpet adhesive holds it in place. Just be gentle when you drill through for the mount.

3M makes a good aluminum tape. I have a 1" wide roll that's lasted a while, but I suspect Grainger carries it. It sticks well. I use it for "soft" radials in situations just like you are talking about.

DLB

Is using 1/2 wave No Ground Plane antennas out of the question? Worked OK for me in a couple of applications I got tossed into......

Dave

No-ground-plane antennas are fine for UHF and 800MHz, I use them quite frequently when I have a lot of tractor installs to do and don't have the time to lift the roof. For VHF they are usually just too big. A tree (or in one instance, an overpass) will damage them. But the UHF and 800 NGP antennas work just fine once you get em tuned.

I'm using VHF, UHF and 900 MHz NGP antennas from Antennex and they work great on my fiberglass camper shell! Low SWR, etc. Maratrac, Spectra's and MCS2000's all like them fine. 100 watts on VHF and UHF and 35 watts on 900. No problems. Oh, I hit lots of garages and trees with the VHF, and it only grinds off a bit of the end.

I just pick up some thin aluminum sheet stock(1/32") and remove the headliner and glue it to the roof.

Unless it's dried fully, you should have someone holding the sheet while drilling to prevent damage and maintain alignment.

I did an install on a Quad (one with bed), and had to use a sheet of steel the mine supplied.
Had to lay it on top, drill it and mount the antenna, and then route the cable down the center, and along the support rails to the radio mounted in the dash(CDM1550).
Supplying power/filtering was the easy part.

I'll have to dig up those pics....

For UHF and 800/900 you can use an electrical 1900 box cover. I use the ones with the knockout. On VHF, I use aluminum cookie baking sheets. You may have to silicone or glue the cookie sheet to the underside, so it doesn't rip a hole in the fiberglass over time.