My duals on '08 Silverado
I know this post is over a year and a half old, but I couldn’t find many pics when I was contemplating dual antennas, but this post was the first to pop up when “Silverado dual cb antennas” is googled, so figured I’d share my setup and pics of my ’08 for anyone else who’s looking. I just completed the installation this week.
I’ll admit, a nice steel whip mounted smack dab in the middle of the top of the cab would typically be ideal, but most of the time, this truck is a lawn ornament as it’s entire purpose is to tow my 5th wheel. A nice 102” could go on top of the cab, but although only 2 feet higher than the trailer, it wouldn’t take long before it found an overpass/power line/bridge support structure/tree that meets the highway minimum clearance requirement and put an end to that antenna.
I’m not that educated when it comes to radio wave propagation, but I chose the co-phase thing because there’s a huge brick being towed behind the cab of the truck, and I thought possibly duals would reduce any dead zone caused by this. I’ve never had a single attached, so I can’t compare. Okay, personally I think the set up looks a tiny bit dumb, but my original reasoning to go with dual antennas outweighs how little I care about how cool or un-cool it looks, so they’re pretty much staying put.
The 4’ firestiks are mounted on firestik’s extended stake bed mounts. The antenna’s are something like 6’3” apart, which is not ideal, but not horrible from what I understand. It took the destruction of a $30 step drill bit and a dozen dremmel cut-off wheels to trim the lower stake bed plate to fit and cut holes in the upper stake bed plate to run the coax through the stake pocket.
The built in meter that came with the Cobra 29 series radio appears pretty worthless when it comes to SWR, but using a $30 Astatic meter, I tuned the antennas with the trailer coupled in an empty area of a big parking lot. I’m no perfectionist, so my SWR readings are (Ch 1/Ch 20/Ch 40) 1.4/1.2/1.3. I measured again without the trailer and the readings I got were 2.0/1.2/1.0 (I thought 1.0 was an unattainable number, maybe my eyeballs weren’t directly in front of the gage, gage is off, I dunno, this is just what I read). The 2.0 is less than ideal, but whatever, it’s when the trailer is coupled that’s more important.
I’ll try to post the pics now…