My first check of commercial LZ1AQ dual loop performance was very successful. Here is the story.
Before going any further, I thought I would check out the full capabilities of the AAA-1C in all its configurations. To do this, I first assembled my two 1 meter aluminum loops into a dual configuration, as shown above.
My two loops and amplifier are centered about seven feet above the ground, mounted on 1½ inch ABS pipe. Each loop is wired into the amplifier A and B connectors, respectively. This structure permits four operating modes. First and second modes are the individual loops. These provide almost identical performance, since the loops are in the same plane.
The third mode is the all important “crossed parallel” configuration. You will find this provides roughly two planar windings, with overall loop inductance reduced by 50%. Finally there is my short electrical dipole mode. While the loops work on the magnetic component of radio waves, the vertical dipole uses each loop as a “wire” to pick up electric parts of radio signals.
This system works with 100 feet of shielded CAT7 cable back to the control box in the shack.
So how happy was I with the performance of this system?
Commercial LZ1AQ Dual Loop Performance in Detail
Here are my key findings.
First, this wideband active antenna provides comparable HF signal strength to my beam on the fifty foot tower. By comparable, I mean within 10 dB or so. The beam provides better on the ham bands (where it is tuned) and for lower-angle signals. But in general, quite comfortable reception.
Second, the two-loop crossed parallel mode improves signal strength and SNR by 5-10 dB compared to a single loop on HF. I was also very happy to experience the much greater 3 dB bandwidth compared to my home-brew versions of the amplifier.
Third, as you would expect, orienting the loop broadside null towards local RFI really cleans things up. Long distance HF signals are less directional, whereas local noise is not.
Finally, the electric dipole mode works but is much more susceptible to local noise, unlike the loops. The magnetic loops reduce local noise by 15-20 dB compared to the vertical active dipole. I will report more results shortly, particularly on lower frequencies below 5 MHz.