Hi low settings and swr readings help

side-show-bob · Fri Apr 29, 2011 8:37 am

Hi all

I have installed two rigs into mine and my mates land rover discoverys and I am having problems with them both.

So the set-up

Both midland 77-099 rigs
Antanar is a mini tornado Stinger

I have got the swr reading down to 3.5 on both on all channels, if I change the hi low switch to low I get a reading of 1.5.

Can I use the rigs on low? What will be the range as we only want them for green laneing so approx 50 mtrs would be fine.

Any ideas?

joe jeep · Fri Apr 29, 2011 8:42 am

on low your only outputting 0.5 watts whereas on hi your outputting 4 watts. you do the math!

side-show-bob · Fri Apr 29, 2011 9:25 am

Dose anyone have anyexperiance with this type of antenar?

stampman · Fri Apr 29, 2011 12:32 pm

basic rules for setting swr are if it is reading higher on channel 40 than channel 1 then shorten the antenna just use high power to set them if it is reading the same all the way through the it is

the antenna has a bad earth
the antenna is up against the body of the vehicle and getting reflection new antenna with higher loading coil
the coax is duff
the mount is duff
the soldering of the plugs is duff
the swr meter is not reading right

that should keep you busy for a while

Dragonfly · Fri Apr 29, 2011 7:09 pm

show us some pictures of your antenna mounyings and radio set up and SWR meterin use.
only use low power on the radios till you get the antenna mounting sorted.

side-show-bob · Fri Apr 29, 2011 8:55 pm

I have tested for shorts and earth, the anetenar is earth to the car body.

Dragonfly · Fri Apr 29, 2011 9:18 pm

Turn the mounting bracket the other way up as it looks from here like the antenna is touching the bracket.
Also make shure that paint is not insulating the bracket from the roof bar.
close in with another picture i cant tell if u have fitted the white plastic insulater in the mount.

side-show-bob · Fri Apr 29, 2011 9:28 pm

the blue cable is a seperate earth which is earthing the bracket and the cable. This is now an old pic, there is a black plastic coller separating the bracket from the top 3/8 connector, i have tested the full length of my coax and i get a good circuit from the inside the car to the top of the antenar with no shorts, and then the same on the earth circuit.

The antenar is not touching i have checked that both visually and with my meter..

I am at a loss..

Dragonfly · Fri Apr 29, 2011 10:12 pm

looking at your SWR readings u either have a dead short or your earth strap is inefective.

Dragonfly · Fri Apr 29, 2011 10:30 pm

Spare wheel CB mounting brackets will ensure a good earth
Landrover Discovery
http://cgi.ebay.co.uk/Land-Rover-Discov ... 2c5c58b6d2

Landrover Defender
http://cgi.ebay.co.uk/Land-Rover-Defend ... 2c5c58b6d1

Dihatsu fourtrack
http://cgi.ebay.co.uk/fourtrak-antenna- ... 2c5c58b6ce

Suzuki jimny
http://cgi.ebay.co.uk/Suzuki-Jimny-Ante ... 2c5c58b6cf

Toyota Rav 4
http://cgi.ebay.co.uk/Toyota-Rav4-Anten ... 2c5c58b6d0

side-show-bob · Fri Apr 29, 2011 10:36 pm

i have a real consern now as that is how i have it wired it all tests good so why the poor SWR readings..

Dragonfly · Fri Apr 29, 2011 10:43 pm

your earth cable is not good. use a strip of metal instead.

stampman · Sat Apr 30, 2011 10:47 am

looking at picture you have a short on the antenna a insulating washer is missing between the nut and the mounting bracket put a new stud mount in and you will be sorted