The answer to your questions is below in blue. I have only built one Yagi for TV and that was years ago and it worked very well pulling in a weak station (before the days of digital TV). I have used several for VHF and UHF ham radio bands.
Quote:
Originally Posted by bobsgarage
Can I choose the length of boom I want? And then build it from there?
It is calculating the minimum length of the boom to match the number of elements you specify. Try changing the number of elements until you reach a point that will fit on the boom length you have available.
Some other questions.
What is an isolated Element?
It is asking are the elements directly connected to the boom (metal to metal) or are the elements insulated from the boom (isolated)
Reflector? What to do with that?
The reflector is the element mounted behind the driven element, in your case you have four reflectors mounted on a vertical boom at the rear of your antenna. The calculated reflector length would be a good starting point for each of your reflector elements. You could probably even replace the reflector assembly you have now with just one reflector element.
Would I change my Dipole dimensions?
Most likely you might need to. Your driven element is a folded dipole configuration because it provides an impedence of about 300 ohms, which works very well when using a 4:1 balun. There is another calculator you can use for that: https://www.changpuak.ch/electronics/Dipole_folded.php
BTW, 26' 7" for a 17 element at 183 MHz whoa!
Keep in mind that a Yagi antenna has a bandwidth of 2 to 3 percent of its design frequency, so a Yagi designed for 183 MHz will only cover enough frequency range for 1 TV channel. They are great and high gain but only when you are looking for one specific channel. |