Again someone who really understood how a Mini-Whip is acting

From the VLF Group on Groups.io 

Re: Practical installation of a PA0RDT mini whip antenna

From: Peter E
Date: Tue, 11 Jan 2022 22:59:26 PST

Hi Ron,

 I have been running one of these antennas for a while now and it seems to work quite well, as I seem to have been one of the few that heard the SAQ transmissions in Australia, and I regularly receive stuff from Germany and the States on 137Khz. I believe there is a bit of a misconception about how these antennas work, in that they should be placed high above ground on an insulated mast. The reality is that the screen on the coax is just as effective an earth as any steel mast, and (I believe) acts as an integral part of the antenna system. I still believe that having the antenna high above the ground improves reception, but whether you have a long antenna on a short mast or a short antenna on a long mast doesn't seem to make much difference.

 My antenna uses a 9M long fibreglass squid pole mounted on a 1M high earth stake. A wire taped to the pole acts as the antenna and is connected to a PA0RDT style amp at the bottom of the pole and earthed to the ground stake. The amp is powered by its own solar charged battery to avoid any noise pickup from the mains. A 1:1 isolation transformer drives a 20M length of double shielded coax buried in the lawn, connected to my shack. A LF common mode choke is also used on the feed into the shack and the coax shield is only connected to ground in the shack.

 If you have no high trees or objects near the antenna, then this is a big advantage as these objects will "shade" the antenna and reduce reception of VLF signals - I can hear this effect very easily with my handheld VLF receiver, walk near the trees and all the Sferics disappear. You also need to get as far from your house as possible, as it will radiate noise like you wouldn't believe, but you will have to do the best with the space you have.

 Just my 2 cents worth...

Cheers,

Peter - VK2AN