View Full Version : Testing antenna

06-01-2017, 07:13 AM
As per my intro post. I'm trying to build a little antenna to test the 2 radios i was given.
I cant remember the specs. It's been about 25 years since i last played with these things.
What should the impedance of the cable be again? 50 or 75?

Then what is the simplest antenna i can build that will simply test tx and rx?
If it works i may invest in a new 5/8 penetrator again.

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06-02-2017, 05:21 AM
For what you are wanting to accomplish, you most likely would be best off with a 50-100 watt 50 ohm dummy load, a decent VSWR/power meter, and a couple of coax jumpers. The coax needs to be 50 ohms. If you plan on building an antenna, there are quite a few that can be built out of 50 ohm coax. A simple vertical dipole would work, or you can buy them for less then $20 off eBay. I would suggest though to spend a little more and get a 1:1 balun as well with a dipole, as to make sure the impedance is near or at 50 ohms. The vertical dipole is sometimes called the T2LT antenna. It's an easy antenna to make and should work fine to use for receiving signals. Again, a 50 ohm dummy load should be used to test transmit power or whether transmit works. They can be had for not much money as well. If you just have regular single final radios and they aren't peaked and tweaked to their limit, a 25 watt 50 ohm dummy load would most likely work. Anything with dual finals or an internal amp, is get a decent 100 watt or more 50ohm dummy load. Also make sure your coax jumpers are made of quality coax!! Keep away from the truck stop swr meters and coax as well as connectors. Belden, Andrew, Commscope, Jefa tech, Shireen, and some others make good coax and if you order the coax, they can place the ends on. If you want to do that, get some good connectors made by amphenol or one of the other companies I listed above.
For simple texting purposes, if you have a couple of trees in your yard you can either build or buy 1/2 wave dipole and set it up as an inverted V or horizontally. Again, if possible get one with a matching 1:1 balun. This will bring the impedance down to 50ohms. And also here is a simple photo of the T2LT vertical dipole antenna as well. The horizontal dipole I spoke of, is one of the easier ones to either build or buy and hang between a couple trees or even a couple of pipes at each end. Get it at least 9ft off the ground or higher. The higher the better.
Sorry for the long post, just trying to make sure I cover as much as I can to try to help you. I am no expert tech or anything like that, but I do know what works for testing radios and such. I would first work on getting a small 50ohm dummy load, and then read up on how to build a simple horizontal dipole. Or you can get a FIRESTICK no ground plane type antenna and mount it as high as you can. The top or side of your roof will work for what you need. And make sure to tune it. Then test. Again, read up on some of the things I have posted. And then make your decision as to what you want to do as far as antennas go. Also the Antron A99 is another easy to install vertical base antenna that won't break the bank. It's basically a 1/2 wave vertical dipole. They come pretty well pre tuned for the cb band out of the box and require only screwing 3 sections of the antenna together and then mounting it. Again, height off the ground and keeping away from any and all nearby obstructions and power lines will work well enough for what you want. All depends on how much or little you want to spend. Again, hope the text wall helps and good luck with whatever you do!! Good day. https://uploads.tapatalk-cdn.com/20170602/8ca191c039585f1f66c197838415c691.png

Here is the image of the T2LT Antenna. Easiest vertical antenna to make to get on air. If you have a place to hang it that is.

06-02-2017, 12:02 PM
Thanks for this comprehensive answer!!!

06-02-2017, 09:34 PM
No worries. Hope it helps some. Be safe and enjoy!!