You may have heard that a picture is worth a thousand words. So, here are some pictures demonstrating my LZ1AQ loop amp performance.
Wednesday evening is a pretty good time to hear lots of 40 meter CW signals here in Calgary, Alberta. Also, a good time to compare my wideband loop to a “real antenna”.
For reference, at the right you can see my Flex 6300 receiving Morse code signals with my external 40 meter dipole, mounted on my 50′ tower. On the left is my 1 meter wideband loop receiving the same signals on my Perseus SDR. The noise floor is about the same, -112 dBm on both systems. Yes, the signals are slightly stronger on the external dipole.
But, keep in mind, my 1 meter loop is still hanging from the ceiling in my basement!
So I think it is fair to say that a wideband magnetic loop does work. In this case, the LZ1AQ loop amp performance at 7 MHz compares well with a full size dipole.
LZ1AQ Loop Amp Performance on SWBC
The next morning, I did a similar comparison on Asian stations arriving on the 31 meter SW broadcast band. In this case, the comparison antenna was a tri-band beam atop my tower. Similar results.
Signals on the loop were slightly weaker but comparable.
Now keep in my that the Perseus has a hot receiver, so this is not really an apples-to-apples comparison. But quite useful, nevertheless.
Down in the AM broadcast band, the LZ1AQ loop amp performance is so strong that I need to add 10 or 20 dB of attenuation on the Perseus to prevent overload. If all I wanted to do was AM BCB DX, a wideband 1 meter loop is a great performer.
All of this has me thinking that I might have to figure out how to make a lightweight rotor to get the most out of the loop. But that is a project for another day.