View previous topic :: View next topic |
Author |
Message |
bristol bloke Lifetime member
Joined: 16 Jan 2008 Posts: 240 Location: bristol
|
Posted: Fri Dec 27, 2013 19:47 Post subject: swr problems |
|
|
Been out trying to tune my stinger aerial today but having problems getting it low enough,I'm getting 2.1 on ch1 and 3 on ch40. I can't lower the whip any lower the whip any less without trimming it,any ideas? _________________ Lee |
|
Back to top |
|
|
Google Sponsor
|
Posted: Fri Dec 27, 2013 19:47 Post subject: Google Ads keep this community free to join! |
|
|
|
|
Back to top |
|
|
Lewis Site Admin
Joined: 25 May 2006 Posts: 16299 Location: Huddersfield
|
Posted: Fri Dec 27, 2013 20:02 Post subject: |
|
|
Possibly a short circuit in the antennae lead, or more likely a poor ground plane.
See this for more info:- http://www.thunderpole.co.uk/cb-radio-guide-groundplane.html
HTH _________________
Copyright is retained for all my photos. Please don't copy them without asking permission
Do not blindly go where the path may lead you. Go where there is no path and leave a trail that others may follow!
ルイス |
|
Back to top |
|
|
bristol bloke Lifetime member
Joined: 16 Jan 2008 Posts: 240 Location: bristol
|
Posted: Fri Dec 27, 2013 20:44 Post subject: |
|
|
Cheers lewis,I have it mounted on the front chrome bull bar which I tested and is grounded but I will try another ground strap.. The coax is new so don't think that could be the problem. _________________ Lee |
|
Back to top |
|
|
Rusty Site Admin
Joined: 11 Mar 2004 Posts: 3358 Location: Hampshire/Dorset border!
|
Posted: Mon Dec 30, 2013 21:58 Post subject: |
|
|
I hate to say it but I told you so in the other thread! You need a good ground plane which a simple wire will not provide. Only mounting the aerial to the middle of your roof will provide the best SWR! But obviously some compromises need to be made in real life. I use my 5' stinger on a mag mount in the middle of my roof but switch to a short aerial mounted with an artificial ground plane on my bull bar when going under low hanging trees etc. it's got rubbish SWR but is okay for short time, I.e. Keep transmitting to a minimum... _________________
|
|
Back to top |
|
|
theFleured Lifetime member
Joined: 11 Jul 2012 Posts: 1810 Location: Newbury
|
Posted: Mon Dec 30, 2013 23:18 Post subject: |
|
|
I store my magmount antenna in the engine bay and mount it on the roof when I need it or the bonnet if I'm going through undergrowth (at least that way I can see if it gets ripped off) _________________
"The thing about quotes on the internet is that you cannot confirm their validity." - Abraham Lincoln |
|
Back to top |
|
|
bristol bloke Lifetime member
Joined: 16 Jan 2008 Posts: 240 Location: bristol
|
Posted: Tue Dec 31, 2013 18:44 Post subject: |
|
|
Looks like it gonna have to be a may mount then,tried a cable earth to the body work and it was worse,will get a smaller antenna now its going on the roof. _________________ Lee |
|
Back to top |
|
|
alex3025
Joined: 26 Nov 2011 Posts: 300 Location: Torrox Spain, Falkirk before that
|
Posted: Tue Dec 31, 2013 21:57 Post subject: |
|
|
On my 400 I had a mount for my ham radio on bull bar with an earth wire running to it and my 300 has a mount on the left hand wing mirror mount for 2meters and a HF antenna on bull bar with no probs at all with SWR you may need to trim your whip by a few mm as long as SWR is below 1.5/2 to 1 it will be fine your not going to get many people on cb now a days so most of the time your be in convoy with other delicas 8-)
Ps radios I use cost upwards of £200 up to £800 so I know what I'm on about just make sure you have a good earth
8-) _________________ "Understeer" is when you hit the fence with the front of the car. "Oversteer" is when you hit the fence with the rear of the car. "Horsepower" is how fast you hit the fence. "Torque" is how far you take the fence with you. |
|
Back to top |
|
|
mu0chn Lifetime member
Joined: 25 Jan 2008 Posts: 175 Location: Guernsey
|
Posted: Thu Jan 02, 2014 0:50 Post subject: |
|
|
I have my antenna mounted on my bull bar and it works fine. I have added a few leads to the body. Do you see much change in SWR when you move the whip up and down. Have you tried adding some wire to the base of the antenna, jump leads will do if they a good length. What you could do with is a MFJ-259B as that will tell you where the antenna is resonant, it may be worth asking around. _________________ Jes
|
|
Back to top |
|
|
|