RF Guru
OctaLoop3 Mini — A shielded active Loop antenna — 500 KHz – 30 MHz
OctaLoop3 Mini — A shielded active Loop antenna — 500 KHz – 30 MHz
Couldn't load pickup availability
If you order coax cables together with connectors, we will crimp the connectors for free before shipping.
The OctaLoop3 Mini requires a small amount of assembly after delivery, mainly tightening a few bolts. We chose this approach to keep the package compact and make worldwide shipping much more affordable.
All our products are handmade, and fulfilment times may vary depending on order volume. Please allow 2–3 weeks for your order to be completed and shipped.
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Experience the OctaLoop family and other RF.Guru antennas live on our remote SDR receivers.
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Included
- OctaLoop3 Mini antenna 60 cm diameter with enclosure
- Stainless steel (RVS316) mounting bracket
- Bias-T (13.8 V) — F-type to SMA
- Short SMA-to-BNC patch cable
- 1 metre 13.8 V DC power cable with Powerpole connectors
Optional
- 10 m INTSAT-170-ELITE 75 Ω coax (2× F-type connectors)
- RVS ground peg (with F bulkhead) + RX line isolator
Major changes since OctaLoop2 Mini
- Power-off input protection: both sides of the loop are automatically grounded when bias power is removed and released for reception when power is restored. This creates a fail-safe muted state with very low additional loading during normal reception.
- Revised front-end protection: the balanced input now uses an updated transient-protection arrangement with reduced input loading.
What remains: the proven wideband balanced receive architecture, out-of-band filtering, 75 Ω feed, coax-fed power and compact 60 cm format.
This is a receive-only antenna. The power-off protection is not a substitute for proper lightning protection and does not make the antenna suitable for transmitting.Product Description
The OctaLoop3 Mini is a shielded active H-field magnetic loop engineered for low-noise HF reception. Its geometry and shielding naturally reduce pickup of electric-field noise, producing cleaner signals even in high-EMI urban environments. Its deep directional nulls let operators rotate the loop to suppress noise from specific directions.
This third-generation design adds automatic power-off grounding at the loop input and a revised, lower-loading front-end protection network while retaining the wideband balanced receive architecture of the OctaLoop2 Mini.
Optimized coverage is 7–30 MHz, while the antenna remains effective down to approximately 500 kHz. This makes the OctaLoop3 Mini a versatile choice for SWL, amateur DXing, utility monitoring and SDR applications.
Key Features
- Wideband Coverage: 500 kHz – 50 MHz (optimized for 7–30 MHz)
- High Linearity: balanced push-pull receive architecture for strong-signal environments
- Automatic Power-Off Grounding: both loop conductors enter a grounded, muted state when bias power is removed
- Reduced Input Loading: revised balanced protection path designed to preserve weak-signal reception
- Input Protection: multi-stage protection helps manage static and short transient events
- Common-Mode Rejection: dedicated feedline-current suppression helps keep unwanted cable-borne noise out of the signal path
- Pre-Filtering: integrated low-pass filtering reduces out-of-band interference
- Protected 75 Ω Output: broadband output interface with additional transient protection
- Bias-T Powered: 13.8 V supplied over the coax through the included injector, with on-board regulation
- Deep Nulls: sharp directional nulls for rejecting local EMI sources
- Compact & Rugged: 60 cm diameter loop with stainless steel mounting hardware
Placement & Grounding
Mount away from power lines and buildings. Typical height: 1.2–5 m. For best common-mode isolation, use an RX line isolator near the antenna and another before the feedline enters the shack, especially on long coax runs. Ground the coax braid at the mast base; our RVS ground peg simplifies this.
Applications
- AM/MW broadcast, SWL, utilities (for example NAVTEX and time signals) and beacons
- Amateur HF (160–10 m) reception and propagation study
- Portable and field setups, plus SDR monitoring
Technical Data
- Frequency Range: 500 kHz – 50 MHz (optimized approximately 7–30 MHz)
- Impedance: 75 Ω
- Power Supply: 13.8 V via the included bias-T
- Polarization: magnetic (H-field)
- RF Connection: F-type antenna feed with SMA receiver output on the included bias-T
- Loop Size: 60 cm diameter (approximately 1.9 m circumference)
- Weight: approximately 1.2 kg
- Operating Temperature: −20 °C to +50 °C
- Pole Mount: 30–68 mm
Mini-FAQ
- What’s the best band? The OctaLoop3 Mini is optimized for 7–30 MHz but remains useful down to MW.
- How high should I mount it? Mount it 1.2–5 m high and clear of local structures.
- Do I need isolators? For best results, use one near the antenna and another before the coax enters the shack.
- How should I ground it? Ground the coax braid at the mast base; the optional RVS ground peg provides a simple weather-resistant solution.
- What happens when power is removed? Both loop inputs are automatically grounded, placing the front end in a protected, muted state.
- How does it handle strong signals? Its high-linearity balanced receive path is designed for strong-signal environments.
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