Checking swr on a radio,would power lines affect it?

[AmericanEagle575]

Good afternoon and Merry Christmas, I have a quick question that u nice folks could help me with. Would over head power lines affect the swr when checking the swr or could they??? Just wondering......I know how to do it,I am just curious that's all. Thanks and have a great day today!!!

 

[kopcicle]

If you are close enough to power lines to have them affect VSWR then you have other more pressing problems . Want to know more ?

 

[Mustang 131]

If you have overhead power lines...move. or change hobbies.

 

[543_Dallas]

My power lines don't bother me and I don't bother them. Damn battery chargers and the washing machine are another story.

Are you talking typical residential power lines or something bigger? Too many variables and not enough info.

Surrounding objects can cause swr fluctuations but most of the time they shouldn't. When I first started trying to run power in a mobile the swr would change when someone pulled up next to me at a traffic light. Long story short I had a poorly installed antenna.

 

[AmericanEagle575]

My power lines don't bother me and I don't bother them. Damn battery chargers and the washing machine are another story.

Are you talking typical residential power lines or something bigger? Too many variables and not enough info.

Surrounding objects can cause swr fluctuations but most of the time they shouldn't. When I first started trying to run power in a mobile the swr would change when someone pulled up next to me at a traffic light. Long story short I had a poorly installed antenna.

543 Dallas, I am putting my Wilson 1000 mag mount back on the trunk lip of my car, and in the driveway where I am trying to tune my antenna to get the best swr for my radio I have residential power lines going overhead. I can't seem to get my swr below 2.0 on 1 and 40, I am guess I am wondering would trying too tune a antenna by powerlines,could it affect me trying too tune it properly, I have a brand new 62 inch whip in it and the coax is brand new also, I had the same antenna on a different car in the same spot and I was able to drop the whip in and got a 1.0 to 1.5 before. I am thinking i may have to trim a little off,but i was just wondering if residential power lines could affect tuning a cb antenna,hope the info helps!! Thanks...

 

[RT431]

I have power lines close by and never had an issue causing irratic swr. Now trees and buildings close by can cause some issues. Try to tune the antenna in an open area away from buildings if that doesn't work then triming is in order. Not all vehicles are created equal.

 

[543_Dallas]

543 Dallas, I am putting my Wilson 1000 mag mount back on the trunk lip of my car, and in the driveway where I am trying to tune my antenna to get the best swr for my radio I have residential power lines going overhead. I can't seem to get my swr below 2.0 on 1 and 40, I am guess I am wondering would trying too tune a antenna by powerlines,could it affect me trying too tune it properly, I have a brand new 62 inch whip in it and the coax is brand new also, I had the same antenna on a different car in the same spot and I was able to drop the whip in and got a 1.0 to 1.5 before. I am thinking i may have to trim a little off,but i was just wondering if residential power lines could affect tuning a cb antenna,hope the info helps!! Thanks...

They shouldn't cause any problems.

If you keep having trouble remove the antenna from the base and check continuity from the center conductor of the pl259 to the so239 on the magnetic base. I bought a Wilson 5000 mag mount recently and the coax wasn't soldered very well inside the base.

If you have a problem and need to resolder it just remove the nut around the so239 and it all comes apart.

 

[sonoma]

what is the swr on 20. that will help you determine if the stinger is too long or not. it it is 2.0 on 20 then you have a problem as 543 Dallas has mentioned.

 

[Road Squawker]

... edit.... I can't seem to get my swr below 2.0 on 1 and 40,... I had the same antenna on a different car in the same spot and I was able to drop the whip in and got a 1.0 to 1.5......

Then the problem is not the antenna or feedline,... it's in the installation.

 

[undertaker]

You may need the 66 inch stinger..

 

[543_Dallas]

Then the problem is not the antenna or feedline,... it's in the installation.

Mine did the exact same thing mounted on the same vehicle. The swr meter in the radio read 2:1. It was around 1.3 the day before. It was a bad connection in the magnetic base. Very poor soldering.

It may be an installation issue but it's a magnetic antenna. There's not much he can do other than moving it around on the car.

Side note for the OP. I had a very low noise level since the antenna was not connected to the center conductor.

 

[Handy Andy]

With the above in mind, and you did say you are doing this in your driveway...

Firstly Welcome to the WWDX Forums....

Now, a typical CB antenna, any TRANSMITTING antenna will have a "Near field" and "Far field" - when one "Near" in produced, the far is what travels away from it.

When you discuss- or check SWR that's these "Standing waves", in antennas this is part of that "Near field" and if there are any conductive - READ:METAL - surfaces, Steel Garage Doors, even a Gas Grill around close to the vehicle they will interact - move the vehicle to an open location and try again.

The near field and nearby metal objects are what is "coupling" to each other and may be adding to your problem. You can see this effect by keying up the system - with the SWR meter in line properly set and on REF setting and moving carefully around the driveway - paying attention to prevent collisions - you can see the SWR can change as you move towards the Garage and away from it - especially if it has a metal door or frame around it. You can park your vehicle in one spot of a driveway some distance away from a Steel garage door, and then move the vehicle two feet towards the door and read SWR again, you'll see it will change, same applies to the Overhead house lines - too close - they can interact.

It just is not a good idea to even bring metal objects, CB antennas, ladders poles - shuffleboard sticks - into close proximity to power lines of any type - just check SWR in an open parking lot - not next to a light pole or Fire Hydrant - yes, they can interact with the antennas' own generated field - so be smart about this.

 

[Tallman]

When you discuss- or check SWR that's these "Standing waves", in antennas this is part of that "Near field" and if there are any conductive - READ:METAL - surfaces, Steel Garage Doors, even a Gas Grill around close to the vehicle they will interact - move the vehicle to an open location and try again.

One thing a lot of people miss is open car/truck doors. When I tune an antenna I don't allow any people near by. I sit in the vehicle with the doors closed and I am well away from any metal poles or power lines.

 

[543_Dallas]

I don't see any difference in swr with my doors open, parked under power lines, driving down the road, etc. When I had common mode issues I had hell with all of this. Even the ground I was parked on made a difference with high power. Different swr on concrete vs dirt.

Even with the wilson mag mount on the work truck the swr is the same with the doors open or closed. If these little things make enough difference for concern I believe there is another issue.

 

[Robb]

One of the most missed reason for weird SWR problems, is the fact that modifying the radio's 54mhz trap coils will automatically skew the output. You can try everything to fix the SWR problem; but if those coils have been molested you are ultimately chasing your own tail.