Stumped with SWR calibration on Uniden 520XL

[Gone_Phishing]

Hi all,

I'm new to all the CB stuff but have read around a bit just to get some footing. So this is the forum I selected for home base. Now my stumping occurs on the SWR calibration of my very first CB radio, a Uniden 520XL with a Little Wil antenna. Their may be no problem at all but still concerned. I went out to an open field with no power lines or signs of human activity, treeless and as flat as possible. My first reading had channel 1 around 2.5 and 40 around 1.2. All after setting the SWR meter as per recommendations read here. So, this should be a short antenna. Piece of cake, I was lucky, pulled it out about a quarter of an inch and it read great about 1.8 (channel 1) about 1.4 for channel 40. Already an expert during my first try, or so I thought. Once back home I did a reading again. Now it's all the opposite and pegged at 3.0 for channel 40, granted I'm in the driveway with a 10kV power line across the street. Is this a true problem meaning that I should never use my CB in the drive way or near power lines as a rule of thumb or is something wicked wrong? Haven't seen any comments about this but then again there are hundreds of posts and threads about SWR meters and antenna calibration. Can anyone throw me a bone here?

Thanks and Cheers to all!!!

 

[w9xxx]

Metal garage door nearby or even another vehicle. my SWR will change in my Suburban depending on which doors are open. In my big truck it will vary with speed, I think because of the bending of the antenna. Don't worry about getting the lowest on every channel. just try to get it the lowest on the channel you use most. most truckers I check with my good meter are over 2.5{and they've usually been tuned by "professional" radio guys that charged them like $50}.

 

[auy23]

I'd go back to that open field and keep raising the antenna until channel 1 and 40 are equal, and see what you get. You also might want to adjust the location of the antenna to see if it improves.

 

[Redneck0410]

As long as it's below 2.0 across the board, LEAVE IT ALONE! All it takes is one wrong snip and your antenna is essentially useless.

 

[sloop]

I agree, go back to the field and set the swr for the lowest reading. SWR is affected by many things such as power lines, metal garage doors, passing tractor trailers on the road, and even wind. Your swr will vary as you move down the highway and the antenna bends. With todays radios you don't have to worry about a high swr damaging the radio (as long as you are running 5 watts)...the high swr only means your signal will not go as far, receive will not be affected.

 

[JayMojave]

Hello G_P: Good advice from Redneck0410 and sloop there.

The Wilson Little Wil Antenna is a compromise, it compromises performance for being a very short antenna. Not saying it won't work, but not as well as the longer antennas. These shorter antennas have a matching coil that has to take up some antenna length to allow the shorter Little Wil Antenna length to work, so tuning the SWR will not be a easy as compared to other antennas. SWR under 2 to 1 will work as mentioned.

Measuring the SWR on the radios meter should be checked with a external SWR Meter and a Dummy Load. Some SWR Meters come with a dummy Load function, and that's a good thing. The Dummy Load should measure a perfect SWR showing that the SWR meter is working correctly, and giving you a example of a perfect antenna load.

Near by metal objects will throw off the SWR, by measuring it in the field with no near by objects, and then moving closer to metal objects you will get a feel for how close it will be to effect the SWR. Good luck.

Jay in the Mojave

 

[Retroradio]

Just a quick thought. Did you check to see if the antenna dropped back down as the setscrew may have backed off. Your readings back home are really close to what you started with.
Ive been running Little Will for years with great success.
Good luck!