Extreme Terrain
4x4Wire Trail Talk Forums: Jeep, Toyota, Mitsubishi, Pajero, Isuzu, Kia, 4WD, 4x4, SUV, Off-Road and OutdoorWire Forums

Search E-Bay for your parts:
Search Amazon for your parts:

Search

Recent Posts on TrailTalk
Gen1 2.6L alternator upgrade
by GrantCee. 09/20/18 09:47 PM
suzi the psychic
by rascott. 09/19/18 05:27 AM
WTB: Mitsubishi Gen1 seatbelt
by GrantCee. 09/14/18 11:04 PM
WTB 3.0L 6G72 12V Engine Assembly
by chadzeilenga. 09/13/18 08:27 PM
fuel tank/ separator tanks
by rxinhed. 09/06/18 04:00 AM
1989 LWB A/T Temp Light
by 87CanadianRaider. 09/05/18 03:46 PM
Echo
by DRLExpress. 08/29/18 02:29 PM
Support 4x4Wire
New Topics on TrailTalk
Gen1 2.6L alternator upgrade
by GrantCee. 09/20/18 09:47 PM
WTB 3.0L 6G72 12V Engine Assembly
by chadzeilenga. 09/10/18 03:08 PM
89 Trooper wiring question
by Resman7. 09/05/18 11:48 AM
fuel tank/ separator tanks
by 87CanadianRaider. 09/03/18 09:28 PM
WTB: Mitsubishi Gen1 seatbelt
by GrantCee. 08/30/18 02:36 AM
Gen 1 & 2 Monteros for sale
by . 08/25/18 02:30 PM
4x4 Gallery
Scar the Cylon Raider
Mercenary Sergeant: Code Name "Sapphire"
Flex test after suspension mods
Clearance check!
Testing the new Kenda Klever 31x10.50x15
More News on the 'Wire

4x4Voice
4x4Wire
MUIRNet-News
OutdoorWire
Who's Online Now
0 registered members (), 122 guests, and 6 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums37
Topics137,912
Posts1,079,635
Members14,783
Most Online581
Apr 3rd, 2017
Previous Thread
Next Thread
Print Thread
Rate Thread
high swr #60836
04/22/03 01:39 AM
04/22/03 01:39 AM
A
Anonymous OP
Unregistered

hey guys

i got my rear bumper two days ago with my cb antenna mount on it. for some reason, when i put my cb antenna on the mount, the swr reading is unbelievably high. i tried to tune it, but nothing works..any suggestions?

From the Off-Road World
Re: high swr #60837
04/22/03 02:45 AM
04/22/03 02:45 AM
Randy Braley  Offline
Getting the Wheeling Fever
Joined: Mar 2002
Posts: 63
Kansas City
A friend of mine with a J#@p had the same problem and fixed it by running a special ground wire from the mounting point to a good ground.


Randy Braley, Shawnee, Kansas
2000 4Runner: TJM T-15, Warn M8000, Elec Rear Locker, Sonoran Steel Shackle Hangers, OME, Maniac Sliders, Cobra 75 WX ST w/ FireStik II, BFG AT KO's 265/75 R16
TLCA #12443
Re: high swr #60838
04/22/03 02:47 AM
04/22/03 02:47 AM
aowRS  Offline
Body Damage is Cool
Joined: Aug 2001
Posts: 1,026
Ellicott City, MD
Is the antenna mounting position low on the bumper, or mounted atop a spare tire carrier? I've read that while a low mount is good for keeping your antenna out of the branches, it'll wreak havoc with the signal, as the antenna sits adjacent to the steel structure of the truck - not above it.

Andreas


2001 4Runner SR5 4WD, Dorado Gold, 303,000+ miles
2014 Audi A4, Monsoon Gray
1995 Porsche 993, Polar Silver
Re: high swr #60839
04/22/03 02:46 PM
04/22/03 02:46 PM
fourwd1  Offline
Body Damage is Cool
Joined: Feb 2001
Posts: 1,681
Baltimore, MD USA
Andreas is correct, a bumper mount and a shortened antenna is not a good combination. You didn't say what vehicle or type of antenna your using, so it's hard to give specific help for your problem. But any antenna needs to be mounted on a surface area of sheetmetal to work properly (refered to as a groundplane, not to be confused with an electrical ground). Bumpers, brushguards, spare tire mounts, etc are not good mounting points if maximum range is desired.

Typically, if your VSWR is high (> 3:1) and adjusting the antena has no effect, a wiring or mounting problem is indicated. The coaxial cable could have an open or a short at the connector end or the antenna end, or the antenna mount could be installed incorrectly with the same result.

Try the SEARCH function for more info, this subject has been discussed to death, and much info is available in the archives.


- seen in FOUR WHEELER mag July 2006 & OFF-ROAD mag Feb 2007 -
'84 4Runner ARBed 5.29s F&R,4.7 & 2.28 t-cases,hy-steer,BudBuilt skid,30spl Longs,36" TSLs,Chevys

'83 P/U, Buick 231 V6,Holley 4 bbl,Weiand intake,Downey headers,TH350 w/700R4 gearset
Re: high swr #60840
04/22/03 03:14 PM
04/22/03 03:14 PM
Dandeman  Offline
Toyota Moderator
Joined: Apr 2000
Posts: 3,748
Chapel Hill, NC
Here's the link to more detailed discussion about acheiving a good RF ground http://www.4x4wire.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=13;t=010309#000021

Understanding what it takes to achieve a good RF ground for the antenna is key...

As discussed, the "counterpoise" or ground plane provided by proper grounding to the rest of your vehicle must be effective to get the SWR down..

What works for DC grounds will not always work as an RF ground. The above link explains...

Re: high swr #60841
04/22/03 04:16 PM
04/22/03 04:16 PM
jataga  Offline
Rock Warrior
Joined: Jun 2002
Posts: 557
Atlanta, GA
You have a short.

Make sure you follow the directions to install the antenna to the T. It is probably not your cable that is shorted but the mount that is not secured properly or you might not have the correct washer in there. Same thing happened to me. After checking it all out, it was the mount.


99 Limited 4Runner 4WD
ARB front Bumper Kennesaw rear bumper
WARN 9500 Winch
Hella 4000s
Re: high swr #60842
04/23/03 05:15 AM
04/23/03 05:15 AM
A
Anonymous OP
Unregistered

I hope this can explain it.
Just made this page.
http://www.pnw4runners.net/tando/cb_coax.htm

This is how mine is done, and shows you what must be isolated as to not get a ground to short condition.


Moderated by  Adam F, Dandeman, kewlynx 

OutdoorWire Websites

OutdoorWire

OutdoorWire

Portal page for OutdoorWire Access and Landuse Central Read More
4x4Voice

4x4Voice

California off road recreation news and information Read More
MUIRNet News

MUIRNet News

News and information about issues affecting outdoor recreation Read More
4x4Wire

4x4Wire

Off road recreation and 4x4 Technical news and information Read More
TrailTalk

TrailTalk

4x4Wire TrailTalk Forums for a variety of 4x4 tech information Read More

4x4Wire Tech Section

Jeep 4x4 Tech

Jeep 4x4 Tech

Jeep Tech from JeepWire - Mods, Maintenance, Tech and more... Read More
Isuzu 4x4 Tech

Isuzu 4x4 Tech

Isuzu Tech from 4x4Wire - Mods, Maintenance, Tech and more... Read More






4x4Wire Social:

| 4x4Wire on FaceBook | Google+4x4Wire on Google+|


OutdoorWire, 4x4Wire, JeepWire, TrailTalk, MUIRNet-News, and 4x4Voice are all trademarks and publications of OutdoorWire, Inc. and MUIRNet Consulting.
Copyright (c) 1999-2017 OutdoorWire, Inc and MUIRNet Consulting - All Rights Reserved, no part of this publication may be reproduced in any form without express written permission
You may link freely to this site, but no further use is allowed without the express written permission of the owner of this material.
All corporate trademarks are the property of their respective owners.

Page Time: 0.010s Queries: 14 (0.004s) Memory: 1.0185 MB (Peak: 1.1278 MB) Zlib disabled. Server Time: 2018-09-24 13:30:46 UTC