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Fitted a new CB this weekend TTI TCB-1100

majic79

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Joined
Nov 9, 2012
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183
Went and bought one, had a chat with the guy at Knights communications (it's a little over 10 miles up the road from me!)

Whilst there, I also picked up a bracket suitable to mount an aerial on the car, and picked up a Sirio ML145 (1/8 wavelength) and some coax for it.

This weekend I picked a location for it (roof bars) then worked out where I was going to wire it and how to get the cable into the cab, and route it while it was in there. I pulled the handles down and carefully pulled the edge of the head lining to one side and could see where the sunroof ended and how much room there was between the roof skin and headlining. Looking at the mounting feet of the roof rack, I reckoned I could get the cable to route through that, which could then be plugged with sealant, and give a tidy finish, bringing the cable easily into the cab. After popping off the cover, I could see there was a place where it would all go with reasonable ease. It took only a second to decide to follow it through!

I'd bought a cable with a PL259 already soldered onto the end of it, so I had to drill a large enough hole to do the job. This turns out to be around 18mm. I didn't have any 18mm drill bits, and if anyone decides to emulate this, don't do what I did, just go to B&Q and buy the drill bit there (£15!)

As I had plenty of spare 2 and 3mm bits, I marked a circle, centre punched equally around it, then proceeded to drill.... this is where i found out that there's a reinforcing bracket under the skin at this point, and there's a cross beam just under that.

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At this point, I was annoyed, so I went online, found out B&Q sold 18mm drill bits, as well as 20mm grommets. Off I went into town, and then I was back to work, 10 seconds with an 18mm drill bit accomplished twice what I'd done, wasting an hour and a half with little drills!

Sadly, as I was chasing daylight a bit, I didn't get many more photos, but I did get a pic of the aerial in place:

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Better pics to come
 
well, that was a wasted effort - going to try dropping the aerial closer to the roof (inverting the bracket) but when we SWR'd it, it looks like it doesn't like being so far away from the ground plane (roof). Magmount in the centre of the roof works fine. So if flipping the mount doesn't work, I'll be re-drilling and mounting in the middle of the roof....
 
I'd say it's more likely to be a problem with cable or connections than the way you have mounted it.
 
Checked them first - all good, no excessive resistance, no shorts where there shouldn't be, was careful not to kink anything (although will double check that tonight when I flip the bracket over)
 
With a multimeter? That will tell you if something is grossly wrong at DC e.g. dead short or open circuit but misses all sorts of things that crop up with RF power. Put the other way round, there's no reason why the way you have mounted it should cause problems ...
 
It could be an earth problem. Looking at the picture it looks like you have some rubber gaskets between the roof rack and roof, this could have an effect on your aerial. Used to have this problem when wanting to mount them on truck mirrors as they used to be powdercoated. You would have to either remove some powdercoat or run a small earth to the door.

Cheers, Mark
 
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