R

RobertOHare

New Member
Cant seem to get a low swr.

i have been trying to tune my cb radio antenna now for like the past 5 days and nothing seems to be working..

i have read all the info on how to tune them but i think i might be struggling getting a good earth,

i tryed a peice of eletrical wire from the base of the antenna to the negative on my battery as somewere i read said that could work.

nothing so i tryed a wire from the base of the antenna to my bull bar and that has took the swr reading on chan 1.20.40 to around 2.5

anyone explane what im doing wrong? i have lots of excess antenna cable that streches from the antenna to my swr meter could that be causing a problem?

and also i have trimmed the antenna by a good few inches and when i done that it seemed to have make it alot worse :(

Help.... ?:(
 
You should have an allen key bolt on the ariel you need undo that and lift or lower the whip bit n swr again.cutting inches off the ariel itself may have nakered it all together.
 
haigy said:
You should have an allen key bolt on the ariel you need undo that and lift or lower the whip bit n swr again.cutting inches off the ariel itself may have nakered it all together.
Click to expand...


i was thinkin that to be honest gona order a new one monday :(

waste of 20 quid !

how can i earth or ground the antenna mount? what do i need and were should it go.

rob.
 
The cb unit should be it's own earth, just mount the casing or bracket onto metal .. ;)
 
Without sounding like a bodging bastard. I've never put an swr meter on any of my cb's. I just fit where I like it and get a mate to test it with. I only use it for convoys and greenlaning,so range doesn't worry me. None of my mates have tested them either. I used thunderpole for my setup,they reckon their kits are swr'd as best they can before being fitted and its only placement and earths that you have worry about.
 
RobertOHare said:
its earths i am worrying about.. how can i earth it.... eletrical wire to were in the lanny?
Click to expand...


Firstly what type of mount are you using?? where is it fitted?

You don't need to earth an aerial, as the outer casing of the coax will earth to the CB's body, which in turn is earthed thru the negative feed wire.

Lots of peeps will tell you that a defenders aluminium body is less conductive and therefore you need an additional earth. They are full of ****e.

I have 1 of these mounts Thunderpole Side Mount | Fixed Body Mounts | THUNDERPOLE.co.uk
and apart from scraping all the paint off the inside of the rear panel. I haven't connected any additional wiring and have a SWR of 1:1.2 Near perfect.. If you need to trim an aerial. then it's done in MM not inches. :doh:
 
MPfive said:
Without sounding like a bodging bastard. I've never put an swr meter on any of my cb's. I just fit where I like it and get a mate to test it with. I only use it for convoys and greenlaning,so range doesn't worry me. None of my mates have tested them either. I used thunderpole for my setup,they reckon their kits are swr'd as best they can before being fitted and its only placement and earths that you have worry about.
Click to expand...

Over short distances and short blasts on shouting ya convoy buds then fine not to swr. But swr are that cheap and easy to do then it would be silly not to and break an expensive cb.
 
redhand said:
Firstly what type of mount are you using?? where is it fitted?

You don't need to earth an aerial, as the outer casing of the coax will earth to the CB's body, which in turn is earthed thru the negative feed wire.

Lots of peeps will tell you that a defenders aluminium body is less conductive and therefore you need an additional earth. They are full of ****e.

I have 1 of these mounts Thunderpole Side Mount | Fixed Body Mounts | THUNDERPOLE.co.uk
and apart from scraping all the paint off the inside of the rear panel. I haven't connected any additional wiring and have a SWR of 1:1.2 Near perfect.. If you need to trim an aerial. then it's done in MM not inches. :doh:
Click to expand...

im using a gutter mount with a 5ft whip antenna from Communication Eleven Homepage :: UK 4x4 CB Radio Specialists - Expert Advice, Competitive Prices & knowledgeable staff - now in our tenth year of trading

might just buy that mount you use and mount it in the same place witg a thunderpole antenna to.
 
SWR is very important if you don't want to keep buying radios, whatever the reading is eg. 1.1 - 2.5 ect. thats what will be feeding back to your radio in watts (reflection=ref on SWR meter)...not good

if it's a dial-a-match antenna don't buy another (tune with 2 metal rings) you won't get the SWR that good on one of them, go for something proper like a Sirio MegaWatt 4000, from knights or from evilbay...they are awesome antennas probably couldn't get much better to be honest i get about 8-9 miles tx & rx on one standard 4 watt power even a DV type whip can tune up good

hope you get it sorted anyway, i know how frustrating it can be ;)

oh don't cut anything off an antenna unless you have an antenna analyser...no point you'll be doing it blind...when you cut the length of an antenna you change the band it can be used for so it won't work with your radio whatever you do after...save buying another or getting a length of steel whip the same what you had in the first place for it.
 
Last edited:
if you have an unbalanced swr ie; higher on 40 than on 1 or vice versa ,
higher on the high number shorten the antena higher on the low number lengthen it ;)
 
new2landies said:
Sirio Hi-Power 4000 PL Mobile CB/HAM Radio Antenna

GKITSS-S STAINLESS GUTTER MOUNT WITH SO239 FITTING

thats all you'll ever need :)

or if you want through body type mount this SO239 HIGH QUALITY LEAD AND MOUNT
Click to expand...

For occasional use when out laning (most 4x4er's) That's just fooking overkill..

Those gutter mounts are crap as the threads strip out of the mounting. and you end up having to weld 2 nuts to the mount. and those button mounts are ok for mounting to a lightbar. but for a defender the PSM-1 Mounts are best, and are perfect for keeping antenna out of harms way.
 
redhand said:
For occasional use when out laning (most 4x4er's) That's just fooking overkill..

Those gutter mounts are crap as the threads strip out of the mounting. and you end up having to weld 2 nuts to the mount. and those button mounts are ok for mounting to a lightbar. but for a defender the PSM-1 Mounts are best, and are perfect for keeping antenna out of harms way.
Click to expand...


so Rear CB aerial mount 3/8 stud 7M cable for Land Rover Defender 110 PSM-1 | eBay

+

"NEW" SIRIO HI-POWER 4000 PL MOBILE CB ANTENNA | eBay

would be a good buy?....
 
haigy said:
Over short distances and short blasts on shouting ya convoy buds then fine not to swr. But swr are that cheap and easy to do then it would be silly not to and break an expensive cb.
Click to expand...

Tis true sort of distances hardly going to make any diffrance unless your in the red
 
you's just carry on having your convo im fine...

haha just kiddin iv just orderd a new whip antenna gona do it properly this time earth the gutter mount to my seatbelt mount get a good earth and try again then i can finaly get rid of all the unsighley wires !
 
You must log in or register to reply here.

Similar threads

ar1g3
P38A Weird antenna
Replies
7
Views
794
ar1g3
ar1g3
MonkeyLander
A 3D print out for the CB radio.
Replies
1
Views
380
Freddie17
Freddie17
J
Disco 2 TD5 Landmark 2004 - hi-line system - aftermarket stereo rubbish radio reception
Replies
7
Views
1K
Jayridium
J
R
Missing infotainment system in Vogue 2010 TDV8 facelift version
3 4 5
Replies
97
Views
3K
roythebus
R
R
Discovery 1 2 heated seat thermostat
Replies
10
Views
1K
The Mad Hat Man
The Mad Hat Man