The VHF and UHF bands
VHF (30–300 MHz) and UHF (300–3000 MHz) cover most professional radio communications: aviation, maritime safety, PMR, emergency services, TETRA, DMR. Monitoring these bands makes it possible to detect interference, document license compliance, and anticipate faults before they interrupt service.
Key services in the VHF and UHF bands
| Service | Band | Notes |
|---|---|---|
| Aeronautical VHF | 118–137 MHz | Tower, approach, ATIS, emergency (121.5 MHz) |
| Maritime VHF | 156–174 MHz | Maritime safety, VTS, channel 16 |
| PMR VHF / DMR | 136–174 MHz | Licensed professional communications |
| TETRA | 380–430 MHz | Public safety, law enforcement |
| PMR UHF / DMR | 403–470 MHz | Industrial and commercial communications |
Why monitor the VHF and UHF bands
In an increasingly congested RF environment, problems appear without warning:
- Interference — malfunctioning devices, unauthorized transmissions, or spurious harmonics can appear at any time; without continuous monitoring, manual identification is nearly impossible.
- Progressive degradation — aging components, corroded connectors, or damaged cables cause gradual losses that go unnoticed until total failure.
- License violations — out-of-band transmissions or excessive power output can lead to penalties and loss of operating authorizations.
TP-RFX for VHF and UHF monitoring
TP-RFX covers 15 MHz to 2700 MHz with a single unit, monitoring the entire VHF and UHF spectrum without gaps.
A sensitivity of −130 dBm makes it possible to detect low-level interference before operators notice any degradation. A 1 kHz frequency resolution ensures precise separation between adjacent channels — particularly important in aeronautical and maritime bands where channel spacing is tight. Frequency accuracy of ±10 ppm meets aeronautical service requirements.
| Parameter | Value |
|---|---|
| Frequency coverage | 15 MHz – 2700 MHz |
| Sensitivity | −130 dBm |
| Frequency resolution | 1 kHz |
| Frequency accuracy | ±10 ppm |
| Adaptive RBW | 3 kHz – 600 kHz |
| Data history | up to 2 years |
| Protection rating | IP67 |
| Power | PoE |
Real-time monitoring and historical analysis
The waterfall display shows RF activity over time and makes it possible to identify anomalies or interference immediately. Automatic alarms trigger on configurable thresholds for signal level, channel occupancy, or the appearance of unauthorized signals.
Up to 2 years of stored history allows reconstruction of any past event. If an operator reports that "the radio wasn't working last Friday," it is possible to retrieve the RF context for that moment, verify whether interference was present, and produce documentation for regulatory authorities.
Case study: aeronautical VHF monitoring
An international airport deployed 8 TP-RFX units to monitor the full aeronautical VHF communications spectrum (118–137 MHz), positioned at the control tower, at runway thresholds, and on dedicated frequencies including emergency (121.5 MHz) and ATIS.
In the first month the system identified:
- Interference from unauthorized radios operating on adjacent frequencies and causing occasional disturbances to ground communications — precise localization, regulatory intervention, problem resolved.
- Progressive VOR carrier level degradation detected gradually, enabling preventive maintenance before any impact on radio-navigation operations.
- Defective backup transmitter generating spurious emissions while in standby — invisible to daily tests, corrected before it could cause an emergency.
Integration with existing systems
TP-RFX supports SNMP for integration with NMS platforms, REST APIs for custom applications, and Modbus for industrial SCADA systems. PoE power eliminates local power supplies, simplifying installation even at remote sites. Multi-user management with a permission hierarchy allows distribution of data access according to organizational responsibilities.
Frequently asked questions
Does a single TP-RFX unit cover the full VHF and UHF band?
Yes. Coverage from 15 MHz to 2700 MHz monitors the entire VHF and UHF spectrum in a single device, with no need for separate instruments for different bands.
How are interference sources identified in the VHF band?
The 1 kHz resolution makes it possible to separate adjacent channels and pinpoint the exact frequency of the interfering source. The waterfall display shows activity over time, facilitating correlation with specific time windows, nearby vehicles, or installations.
Is TP-RFX suitable for aeronautical use?
Yes. Frequency accuracy of ±10 ppm meets aeronautical service requirements; sensitivity of −130 dBm makes it possible to detect weak interference before it degrades tower-to-pilot communications; IP67 certification ensures continuous outdoor operation.
How much history does the system retain?
TP-RFX retains up to 2 years of historical data, accessible from the web interface to reconstruct any past event and produce documentation for regulatory authorities.