Troubleshooting mylack of distance, receivng and transmitting.

I run a 2012 Cascadia with a stock Cobra 29, a good piece of 18' coax and a vice grip mount on the rear airline swing bar, connected to a 5.5 ft. Francis. SWR about 1.6, normal talk range 4-5 miles. Hears as far as 10-12 miles average. Same results with a 12' piece of coax. Bird perch mount like yours didn't work nearly as good on my truck. Couldn't get SWR down. 5.5 ft. worked way better than a 4 foot.

 

Is Tramflex RG-8/x a decent coax?

Yes it is just fine ....

 

A 5.5 foot wll almost beat a 4 foot .... no mater who makes it .

If you are using coax to tune a antenna there is a PROBLEM with your antenna ...

 

I was taught a long time ago that if you think it's the ground.. try putting a piece of wire between the antenna and mount to an unpainted frame bolt and see what the SWR comes out as... when I had one on my jeep I always had a 2.5 but when I put a groundstrap on it I was 1.1. Always worth a shot and cheaper than stabbing at things.. those mirrors don't provide any type of grounding in the least so I bet thats at least half the problem.

 

Yep good idea

 

With the antenna disconnected from the radio, use a simple circuit test light connected to the positive 12v in your truck and the other end to the post of the antenna bracket. If it does not light up, you don't have a good ground. And from your pic it looks like the ground would have to work thru the door hinges, pins, latch, etc., not good or consistent. A seperate ground wire from the post to the frame may help.

A taller antenna always helps.

 

There are several threads on here about the Cascadia. First, I had pretty good luck with the Francis 5x5 on the back of the cab. I put the bracket on the air line holder bracket. Only problem was it was taller than the trailer. Good for transmit/receive, bad for hitting things. Plus, I slip seat so running 27ft of coax from the rear of the cab to the dash takes a few minutes longer (plus the need for cable ties) than just running one thru the door.

I have experimented with a similar bracket for the Cascadia. No matter what antenna I ran, I had to lean it forward to get a decent SWR. Except for the antenna I'm running now, Wilson 2000 w/18" shaft, the other antennas, various length Francis antennas and a Monkey Made, had to be leaned so far forward, 45 degrees or so, to get a good SWR that it killed the signal. The antenna I'm running now is only leaned forward about 15 degrees and I am at a 1.7:1 on 19 and it gets out better than what I've tried so far. Oh yeah, that is with 18' of coax, using 9' of coax raises the SWR up over 3:1, as does 6ft or 12ft. My next test is to use a shaft long enough (will have to make one) to raise the load on the Wilson to roof level, above the door, and attempt to stand the antenna straight up.

Doing some bonding from the mirror bracket to cab then to frame would no doubt help and probably eliminate the need to use a specific length of coax.

I suspect you have a dangerously high SWR currently and that could be a big part of your problem. Plus, most of your antenna is surrounded by metal.

 

Picture of above described antenna set up. Well maybe not?????? Tried to post picture but it didn't show up??????

 

I know exactly what your saying Mike. Ive had the same experiences with my Volvo but didnt have the heart to tell all the fellas with their degrees. Lol, they are alot of help though.

 

Looking at the picture, it's obvious that your problem is the location of the antenna. Too much of it is below the roofline. The truck body is absorbing the radiated signal and detuning the antenna.