CB unit cuts out at 30 yrds?? wat have i done wrong?

[Freelaner]

ok MaxyMan with thanks to Redhand, for telling me what the mount was cos i'd never seen it afore, here is a guide to all you need to know.

Installing CB Into 4x4's , Fitting the Aerial & Mount , Fitting a PSM-1 Mount

 

[Pikey]

A pic of my old 90. N/s mount was for a 2mtr/70cm ham radio O/S mount was for CB with same orbitor as yours. it didn't need any "tuning". Sort out the problems with the mount and then get an swr meter. Maplins sell 1. or look on ebay. If it does need tuning undo the small grub screw in the base where the aerial joins the spring and move the aerial up or down. and recheck.

 

[MaxyMan]

Thanks thats just what ive been looking for.

 

[deaftonewonder]

Good earths are essential for creating the mirror earth wave of the wave from your antenna

check all connections + insulation points.

id expect to be able to transmit 30ft from the cable jack into the unit so all that coax + antenna arent doing much at the moment.

when working with any comms, remember;

Vertical -ensure the antenna is vertical
(+when your in the bush, not touching any branches)
Line of sight -if you can see the receiving station you should be able to achieve comms
Avoid -objects that screen; buildings, power lines etc
Movement -may clear dead spots
Position -move the antenna not the radio set!
Safety -when approaching a veh, touch the back of your hand to the metal, this way if anythings frayed you'll get a jolt but your hand will be repelled -if you touch with an open palm theres the potential for the muscles in your hand to clamp on + fry ur ass!

just dusted off my manuals....

swr (or VERTICAL STANDING WAVE RATIO) is a measurement of an antenna's (its not aerial!) Tx / Rx efficiency.
-its expressed as a ratio, (ie 1:1)
meaning 1 wave is transmitted (Tx) : 1 wave is received (Rx).
1:1 is the best you can poss achieve, the higher the deviation away from this, the less efficient your antenna.

The most efficient antenna length is one quarter of the wave length for the frequency your using.

so for a VHF freq use this formula;

1/4 wave = 75/freq (in MHz)

For really efficient VHF comms, the antenna needs to be raised above MEH (min effective height)
this is where your antenna is higher off the ground than one full wave length (of the freq your using) easily achievable on a veh.
this creates 50% space wave + 50% ground wave
the formula to work out your antenna's MEH; 300/freq in use.
Remember, the antenna needs to go higher than the number you get from the equasion!

Lil' tip,
if you tie a piece of string to the top of your antenna and bend it over so it sits at upto 45degrees (peg the string into the ground) you can work at much longer ranges

 

[MaxyMan]

Thanks for all the help great people on this forum. Got it working, turned out that I had the mount on wrongly so the live was half earthing out. I sanded back the paint on the tub aswell which I think has helped it a lot. Was my silly mistake having no instructions haha. Thanks.

 

[haigy]

mines in centre of my disco and swr came in at 1.2 throughout the channels

swr are chrap enough to buy so get ya own n carry it with you any trouble with trees thrn check swr again

 

[Freelaner]

glad you got it sorted

 

[Pikey]

Good earths are essential for creating the mirror earth wave of the wave from your antenna

check all connections + insulation points.

id expect to be able to transmit 30ft from the cable jack into the unit so all that coax + antenna arent doing much at the moment.

when working with any comms, remember;

Vertical -ensure the antenna is vertical
(+when your in the bush, not touching any branches)
Line of sight -if you can see the receiving station you should be able to achieve comms
Avoid -objects that screen; buildings, power lines etc
Movement -may clear dead spots
Position -move the antenna not the radio set!
Safety -when approaching a veh, touch the back of your hand to the metal, this way if anythings frayed you'll get a jolt but your hand will be repelled -if you touch with an open palm theres the potential for the muscles in your hand to clamp on + fry ur ass!

just dusted off my manuals....

swr (or VERTICAL STANDING WAVE RATIO) is a measurement of an antenna's (its not aerial!) Tx / Rx efficiency.
-its expressed as a ratio, (ie 1:1)
meaning 1 wave is transmitted (Tx) : 1 wave is received (Rx).
1:1 is the best you can poss achieve, the higher the deviation away from this, the less efficient your antenna.

The most efficient antenna length is one quarter of the wave length for the frequency your using.

so for a VHF freq use this formula;

1/4 wave = 75/freq (in MHz)

For really efficient VHF comms, the antenna needs to be raised above MEH (min effective height)
this is where your antenna is higher off the ground than one full wave length (of the freq your using) easily achievable on a veh.
this creates 50% space wave + 50% ground wave
the formula to work out your antenna's MEH; 300/freq in use.
Remember, the antenna needs to go higher than the number you get from the equasion!

Lil' tip,
if you tie a piece of string to the top of your antenna and bend it over so it sits at upto 45degrees (peg the string into the ground) you can work at much longer ranges

Cheers I'm sure the OP understood every single thing you said there. NOT!!! if ya gonna post advice. do try it in plain english and targetted at the person asking the advice.. I've got me intermediate licence. & you lost me with all the technobollixs..

 

[deaftonewonder]

im sure if a ****wit marine can understand it, someone with an lofty licence can use it?

theres alot of landy stuff im still learning with the help of guys on here
but radios i know about -so when someone says their comms arent working, 'what have i done wrong', isnt it better to help them understand WHY its not + not just HOW to fix it?

i get targetting the person asking but the above info is universal + may help others searching the topic.

every days a school day m8 -if ya dont understand it, asking wtf im on abouts always better than writing it off as technobollixs...... never know, might just learn sumthin to add to that licence