Excellent vid. Strong work!!!!

Good job Colin,definitely need an analyser for trimming the lines

Great video. Really nice to see the math, then see it applied.

Fantastic Colin,thanks mate. I’m looking forward to the actual build of the antenna. 73 Chuck VK2SS

Excellent Colin : )

Thanks Colin, good of you to share this with us, 👍

yet another great video  mate keep it up mate, it's much appreciated, 73's for now

VERY !! HELPFUL AND THANK YOU SO MUCH FOR SHARING YOUR WORK, BULDING A 2 ELEMENT VERT. FOR 3.825

Colin, Great video... I tried the link to the calculator, and it gives a Calculator no longer in service error.   Shame because that is really a useful tool.    For the most part you can trust the velocity factor of good cables, but it is also frequency dependent. It is sometime good to check it with a VNA or Nano VNA if you have one available.  Some of the cheap cable coming from overseas (Asia) you need to check the velocity factor they can be a good bit off.    Thanks for the inspiration you provide and the work you do...  Still working on the 40m 1/8 wavelength vertical array.   I spoke to a broadcast engineer friend.  He provided some advice and some things to be careful of in this design.

I wonder why RG213 does not show velocity factor of 0.66. The formula for calculating VF is: VF = 1/(SQRT(K)), where VF is Velocity Factor, K is dielectric constant. Polyethylene has dielectric constant of 2.3 , so this formula may give you 0.76938... , but it depends of the manufacturer and what actual material they use. It is not possible to calculate velocity factor for foam dielectric.

You should always include the units for the values when you do calculations like this.

if you could only have one HF antenna, what would it be? Wondering if there is a single antenna that will perform well for NVIS and long distance

Online calculator above is out of service as of this 12-26-21

Great calculations but is your vision ok cause you writing in between the line .

A very informative video, many thanks. Does the 90 degree minimum stay the same when the connector is added to the cut end of the cable?

You inspired me to finally put together a 2 element 40m array. Have one questions on measuring the feedlines and delay line. Should the control box be inline when the measurements are taken to take in account the extra wire length inside the control box?

Quick question for you why would you choose a one quarter phaseline instead of a 1/8 phasing line.

Are you absolutely sure that the velocity factor is 0.66? Have you measured, calculated, and verified it?