What’s Better than One 1/4 Wave Vertical? —How About Two?…

Next experiment in vertical HF antennas is trying a 1/4 wave vertical “fan dipole”. The 7.2m fishing rods are a perfect support for up to a 20m wire radiator. I set a length of 3/4″ PVC pipe about a foot away from the existing 40m 1/4 antenna. I also removed the last two section of fishing pole as they are too flimsy and are not needed length to support a 20m wire. I connected this wire to the point where the 40m wire connects and after a bit of tuning had three dips in the SWR. 7 MHz is the main tuned frequency, 14 MHz is the new radiator and 21 MHz is the third harmonic of the main radiator. Here is the SWR plot:

swr

Here is what is looks like:

20170805_225609323_iOS20170805_225616530_iOS

So far this works well as before on 40m and 15m. The performance on 20m looks a little shaky still as I am seeing my SWR swing around a bit when transmitting. This indicates to me that my feed line is picking up RF at that frequency. I’ll be building an Ugly Balun soon to try and clean that up. The antenna hears very well on 20m with very little noise so I f I can solve the SWR issue I should be in good shape.

 

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