8230AJ GPS/GNSS Anti-Jam Outdoor Antenna
Horizon-blocking GNSS timing antenna — 20 dB+ interference rejection against ground-level jammers, IP67, drop-in replacement for standard antennas
The 8230AJ hardens the most exposed single point in any GNSS-timed facility — the rooftop antenna — using passive horizon-blocking antenna technology. Its unique conical reception pattern receives at full strength from the zenith while rejecting signals from low elevation angles (15 dB or more rejection below 30 degrees elevation), which is where nearly all interference originates: terrestrial transmitters, communications towers, and intentional jamming from illegal 'privacy jammers' carried in vehicles. Satellites used for timing sit at high elevation, and a timing receiver needs only a few of them, so with modern multi-constellation receivers the 8230AJ delivers the same timing accuracy as a standard antenna plus 20 dB or more of interference rejection — with no active electronics beyond a standard LNA, no power penalty and no export complications.
It is a high-gain (40 dB) active antenna covering GPS L1, GLONASS L1, BeiDou B1, Galileo E1 and QZSS L1 (1559-1606 MHz), using a three-stage low-noise amplifier, mid-section SAW filter and tight pre-filter for greater than 50 dB out-of-band rejection against saturation by sub-harmonics and L-band signals. Terminated with an N-type female connector and powered at 2.5-16 V (19 mA typical) over the coax by the timing receiver, it supports cable runs to 125 m on LMR-400 (250 m with the Model 8227 inline preamplifier), and is a drop-in replacement for the standard Model 8230 — same cabling, same pipe supports, new L-bracket included. The IP67 housing with UV-stabilised high-impact polycarbonate radome and Zamak metal base survives rain, ice, snow and salt spray from -40 to +85 C.
For airports in the GCC, where GNSS interference events around airspace are a documented operational reality, fitting the 8230AJ to SecureSync or other GNSS time-server installations is the lowest-cost first layer of timing resilience: it stops most ground-originated jamming before it ever reaches the receiver, complementing detection software and oscillator holdover. Accessories include flat-roof and rugged post mounts, surge suppressor, splitter and plenum-rated cable assemblies.
Technical specifications.
| Type | active antenna with passive horizon-blocking (anti-jam) reception pattern |
| Antenna pattern | 0 dB at zenith; >=15 dB rejection below 30 degrees elevation; 20 dB+ effective interference rejection vs standard antenna |
| Frequency | 1559-1606 MHz — GPS L1, GLONASS L1, BeiDou B1, Galileo E1, QZSS L1 |
| Gain | 40 dB internal LNA (three-stage, mid-section SAW, tight pre-filter) |
| Out-of-band rejection | >50 dB below 1500 MHz and above 1650 MHz |
| Max cable length | 125 m (400 ft); 250 m (800 ft) with Model 8227 inline preamplifier |
| Connector | N-type female; recommended cable low-loss LMR-400 equivalent |
| Power | 2.5-16 V, 19 mA typical, fed by receiver over antenna coax |
| Enclosure | UV-resistant high-temperature polycarbonate radome, Zamak white-metal base; IP67 |
| Temperature range | -40 to +85 C |
| Size | 100 mm dia x 101.5 mm H (127.2 mm incl. connector); weight 370 g |
| Mounting | L-bracket + hose clamps included (pipe/pole); optional flat-roof mount (8213) and rugged post mount (ANT-KT); drop-in replacement for Model 8230 |
| Warranty | 1-year limited |
| Ordering / variants | Single model 8230AJ. Accessories: Model 8213 flat-roof antenna mount (ballasted, 39.7 cm dia), Model 8224 antenna splitter, Model 8226 surge suppressor + grounding kit, Model 8227 inline preamplifier, Model 8235 PVC mounting pipe, ANT-KT rugged post mount, standard and plenum-rated cable assemblies, weather-proofing kit. |
Certifications.
Use cases.
- ›Hardening rooftop GNSS timing antennas at airports against ground-level jamming
- ›High-interference urban/airport sites where standard GNSS antennas lose lock
- ›Drop-in anti-jam upgrade for existing Model 8230 time-server installations
- ›First-layer interference protection for SecureSync/NTP/PTP timing chains feeding CCTV, networks and DAS
- ›Timing reception in areas affected by privacy jammers and terrestrial L-band transmitters