Post by Mike Harding on Jan 21, 2024 16:47:37 GMT 10
Antennas are highly complex items but often, if one is not looking for perfection, they can be simple to make.
I have a UHF CB for which I wanted a simple antenna, something which could be installed inside the vehicle using no more than sticky tape. Such an antenna will not generally operate over vast distances but it will probably be as good as anything commercial you can buy for $50. And as UHF CB is "line of sight" it really doesn't matter how much your antenna costs or how masculine it makes you feel it's never going to go very far.
Having spent the day messing around with some basic RF instrumentation and cajoling my long suffering Richard into modeling the result this is what I've ended up with:
It comprises a piece of co-axial cable to the end of which are attached two pieces of wire each 125mm long. My implementation is very sloppy and the co-ax should be trimmed back as short as possible which I shall do when I install it into the vehicle. Nevertheless it works well.
If you make one then cut the two "125mm" elements to 140mm initially then gradually cut them back 5mm at a time until you can receive the optimum signal from a local repeater.
That's it. A cheap, basic, but very usable UHF CB antenna.
I have a UHF CB for which I wanted a simple antenna, something which could be installed inside the vehicle using no more than sticky tape. Such an antenna will not generally operate over vast distances but it will probably be as good as anything commercial you can buy for $50. And as UHF CB is "line of sight" it really doesn't matter how much your antenna costs or how masculine it makes you feel it's never going to go very far.
Having spent the day messing around with some basic RF instrumentation and cajoling my long suffering Richard into modeling the result this is what I've ended up with:
It comprises a piece of co-axial cable to the end of which are attached two pieces of wire each 125mm long. My implementation is very sloppy and the co-ax should be trimmed back as short as possible which I shall do when I install it into the vehicle. Nevertheless it works well.
If you make one then cut the two "125mm" elements to 140mm initially then gradually cut them back 5mm at a time until you can receive the optimum signal from a local repeater.
That's it. A cheap, basic, but very usable UHF CB antenna.