CB Question

Just fitted a basic Midland 98 Plus along with a mini orbitor antenna...

The orbitor was originally a Mag mount, but I've removed the main antenna from the magnetic base and now have it fitted on a mount on the roof rail just above the drivers door..

SWR is at 1.6 on Ch 1, 1.5 on Ch 40 and 1.3 on Ch 19 so I assume everything is healthy enough..



Now the question. To get the SWR down to those levels I had to adjust the left whip out of the coil by about 2"...

As antenna is painted, it looks a bit naf but more importantly, the tiny grub screw that holds the whip into the coil is only just bitting the bottom of the whip and I don't think will be secure.

What are my options for inceasing the electrical length of the antenna?

If I fit a quick release fitting between the mount and the bottom of the antenna, will that be added electrical length? I assume it will be, but not 100% certain as it would below the coil/spring...

Also, do the Thunder Pole quick release fittings hold up to offroad use?

Regrads,

Peter

The grub screw will do just fine and taking 2" off is no probs. With those readings leave it alone!

Kirkynut

if your in doubt, pout some threadlock of superglue in the grubscrew threads.

My SWR 's 1.2 - 1.4 across the range. I use a mag mount, so I know if this was replaced with a propper bodymount, it would be well below 1.

I get about 10 - 20 miles range in open country and 5 - 6 miles in a builtup area

i bought a small springer for my mag mount on roof, the guy in the CB shop says dont need to swr it... i dont have any experience of CB's so kinda believed him but was unsure as i though all aerials should be tuned?

Yes all ariels "should" be tuned as a poorly tuned ariel will fry the output stage of your CB (think Feedback).

However these days, most ariels are preset to a nominal setting that will, on average be suitable for just Plug & Go.

Also, I guess most people will use pre-made lengths of coax too.

If you are customising an install with long lengths of cable / soldering your own PL-259 plugs etc, these factors will affect the output resistance of your "rig" .. and hence then it may be necessary to adjust your ariels tuned length to a more optimum configuration.

Generally though, factory defaults on standard equipment "should" be fine for most people

As a precaution, I would check the SWR of the setup if you have access to someone with an SWR Meter

biggaz wrote: i bought a small springer for my mag mount on roof, the guy in the CB shop says dont need to swr it... i dont have any experience of CB's so kinda believed him but was unsure as i though all aerials should be tuned?

Mine was supposedly pre adjusted as well and the SWR 1:3 on Chl 40 when I first fitted it!

What part of the country are you? If you're with in a reasonable drive, I'd be happy to pop over with the SWR meter and give it a go..