DX Engineering is excited to announce that it now carries the Aziloop DF-72 from QuietRadio, a dual-mode, multi-directional antenna system for VLF to HF reception, with no rotator and no control cable required—only a single convenient coaxial cable. Per the manufacturer, the small-footprint system boasts capabilities that single loop antennas cannot offer, and it can be operated remotely, wherever an Internet connection is available.
The Aziloop comes with the Loop Control Unit (LCU), Common Interface Unit (CIU), and software app that provides users with intuitive controls of the antenna. With the Aziloop system, the antenna—which remains stationary during operation—is rotated electronically by the user.
The Aziloop system also includes DC power, USB, and 3.5mm-to-phone AUX cables, and two SMA to BNC adapters.
What You Supply
Users provide a 13.8 V power supply, a Windows PC, and a build of your own fiberglass supported antenna, consisting of two perpendicular wire loops, sized to give optimum performance based on target frequency and ambient noise. The Aziloop allows you to use a low-visual-impact, small-footprint antenna comprising a pair of orthogonal loops (one oriented north-south, the other east-west) plus a ground rod connection. Aziloop notes that many antenna arrangements are possible. All you need is a supply of stranded insulated wire (or something similar), and a central non-metallic mast or post, typically no higher than 25 feet, and often less than 12 feet in height, depending on desired band coverage.
Dual Modes
Created by Dave Evans, GW4GTE, founder of U.K.-based QuietRadio, after five years of development, the Aziloop (Az is short for azimuth) employs Stepped-Azimuth™ technology to rotate the antenna electronically and produce multiple headings in two modes: 72 uni-directional headings in K9AY mode and 36 bi-directional headings in Loop mode from the pair of user-installed perpendicular vertical loops. The result is a choice of 108 heading/mode combinations. You can easily switch between Loop mode and K9AY mode using the interface’s mouse wheel or buttons.
- In K9AY mode, the Aziloop operates as a K9AY terminated loop giving a uni-directional cardioid pattern.
- In Loop mode, it produces the classic small loop figure-eight bi-directional pattern at low angles, and omni-directional pattern at higher angles.
“The directionality is very effective, and you can usually find a direction that will allow the contact to be made even with strong QRM, and even if not beaming in the correct direction,” wrote Steve, G0KYA, in his review of the Aziloop in the May 2024 issue of RadCom, the Radio Society of Great Britain’s monthly magazine.
Note: The K9AY antenna is a closed-loop RX antenna developed by Gary Breed, K9AY. The popular antenna was first described in the September 1997 QST article, “The K9AY Terminated Loop—A Compact, Directional Receiving Antenna.” The article’s subhead notes, “Wish you had enough room for an effective low-band receiving antenna? You do!”
More Aziloop features and benefits:
- Designed for Long-Lasting Outdoor Use: The LCU is housed in a durable IP67-rated waterproof enclosure made from ASA (acrylonitrile styrene acrylate) thermoplastic rather than ASB for excellent weather and UV resistance, zero corrosion, and minimal condensation. The lid of the enclosure is secured with six stainless steel screws which clamp it firmly in place via a waterproofing gasket The enclosure includes integrated pole mounts allowing installation to be completed quickly and easily with just a couple of cable ties or jubilee clips.
- No Control Cables: The antenna feeder also carries power and control signals to the LCU. This makes antenna upgrades a breeze if a coax feeder cable is already in place.
- Full Control: The LCU has a switchable balanced preamplifier with a gain of nominally 18 dB, optimally placed at the antenna to maximize signal-to-noise ratio and swamp any external noise pickup on the feeder. Ahead of the preamp are three selectable seven-pole filters, two low-pass and one high-pass. The high-pass filter and one low-pass filter overlap to produce a band-pass response as a fourth filter option.
The terminating resistor in K9AY mode is adjustable in 50-ohm increments from 250 ohms to 950 ohms.
The CIU has a five-position attenuator: 0 dB, -6 dB, -12 dB, -18 dB and infinity (which isolates the receiver, terminating it in 50 ohms).
The combination of LCU preamp and CIU attenuator gives around 36 dB of level control allowing the user to achieve the best balance of signal-to-noise ratio versus dynamic range.
The CIU also has two auxiliary I/O lines that can be separately configured as inputs or outputs. These can be operated remotely as well as locally. Uses include additional antenna switching, controlling other equipment, or in a remote scenario, power failure indication, intruder alarm, temperature alarm, remote fan control, and equipment reboot.
- Remote Operation: You can control Aziloop from anywhere there’s an Internet connection, as client/server mode is built into the app as well as local mode. At the antenna end use a PC via USB with the app in server mode, or directly connect to the CIU Ethernet port. At the client end set the app to client mode.
- Mute Facility: An auxiliary I/O channel can be set up as PTT sense line to quickly isolate a connected receiver and protect the LCU from high RF levels. The second channel can be configured as another PTT input or a PTT out keying line with a selectable delay. There is also a mute (talk) timer with visual display within the app.
- Omni-Rig 1.2 Support: Aziloop now supports Omni-Rig, with extra functionality driven by your transceiver’s frequency, mode, and PTT state.
In Summary
“The Aziloop is an innovative receive antenna system that does away with the need to use a rotator and can be fed with a single length of coaxial cable. It may suit shortwave listeners and radio amateurs who operate on the lower bands,” wrote G0KYA. “It offers a low-noise solution for the reception of signals from VLF to HF and can be quite addictive to play with.”
Read the full review from G0KYA here.
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Find more details and order the Aziloop VLF-HF Multi-Directional Receive Loop Antenna System at DXEngineering.com.
