In our office we have a lot of UHF radios, Handhelds and Mobiles, but we do not have Base radio to serve as our Control Center for our radio communication network.
In my research I came up with an idea that Mobile Radio and Base Radio are the same, the only difference are Mobile Radio get its power at the battery of the vehicle and uses mobile antenna mounted on magnetic mounting at the rooftop of the car while Base Radio uses 12 Volts Regulated Power Supply and Having an external aerial antenna mounted on a tall structure likes tall building, tall tower and other elevated areas so that it can have a better transmission and reception of signals.
And now I research the cost of 12 Volts Regulated Power Supply and Base Antenna, It cost as a lot and it is hard to buy because of the operating frequency that is assigned to us.
That is why, I am going to build a UHF 800MHz antenna for our Hytera Base radio at the office with readily available materials and others can be bought locally.
*DISCLAIMER*
SOME PHOTOS ARE NOT MINE, IT IS CREDITED TO THE OWNER OF THE PICTURES
Designed Guides
I have search Google.com and it gives me this sites for our references
In the calculation you can refer to this site:
https://jeroen.steeman.org/Antenna/collinear-coax
For additional theories you can drop by to this other sites.....
https://k7zgq.blogspot.com/2012/12/coax-cable-collinear-wireless-and-or.html
http://www.repeater-builder.com/antenna/wa6svt.html
Antenna samples from sites above for your Understanding
For the materials, I used the existing RF50 - 1/2 inch coaxial hardline cable for the element that is cut into desired length according to calculation, and copied the 1/4 wavelength balun designed with 16 Elements for high gain result, I also used the available connector for the said RF50 cable and for protection of the elements, I cover it with 3 inches PVC pipe with PVC Cap, only the connector can be seen for the transmission line.
For the tuning of the antenna
In tuning the antenna, I used a Chinese made Antenna Analyzer to get the correct operating frequency and carefully cut the element above and adjust the balun connection below for lowest SWR.
Lastly ......
These are the update pictures of my work for your additional reference....
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