Many thanks to SWLing Post contributor, Dale Parfitt, who writes:
I wanted to mention a receive only antenna that I am using at my home QTH. I do a lot of NDB logging during the winter below 500kHz, some AM band DXing and 160M. In the past I have had Beverages, homebrew Flag antennas, Shared Apex Loop Array and now last month I installed the new Quiet Radio AziLoop:
With the Array Solutions Model AS-SAL, I could electrically rotate in 45 degree increments and also flip the direction by 180 or make it bidirectional. Click here to download the manual (PDF).
You can read the features of the AziLoop on Dave’s site. But the outstanding feature is rotating electrically every 5 degrees and 2 modes- small RX loop and K9AY. In K9AY mode I can achieve up to 30dB F/B and the rear null is very sharp. If it did not rotate in 5 degree increments, you would not even see the rear nulls.
But here is where it really stands out. The K9AY design, like the flags and Ewes, has a terminating resistance. By varying the value of that resistance via the AziLoop App, one can achieve skywave nulls. The value of that terminating resistance changes from day to night etc. So using that feature, I can often reduce co-channel or adjacent channel QRM or thunderstorm QRN. Small loops (aka magnetic loops) cannot do that. They are omnidirectional to skywaves.
Anyway, I mention this as some of your site readers both ham and SWL might find it interesting.
I built mine from telescoping fiberglass poles and it is completely standalone- no loops on the ground stakes etc.
I have no commercial relationship with Quiet Radio- just a very satisfied client.
Thank you for sharing this, Dale. I was not aware of the Aziloop. Fascinating!