POTOMAC / Potomac Instruments Measurement and Monitoring Equipment

Precision test and measurement instruments from POTOMAC / Potomac Instruments for radio transmission and communications. Professional equipment selection according to plant engineering specifications.

POTOMAC / Potomac Instruments PI-4100 Medium Wave Field Intensity Meters

The Potomac Instruments PI-4100 precision field strength meter covers frequency bands from 520 kHz to 5.1 MHz. Engineered with a calibrated loop antenna, GPS tracking module, and spectral analysis hardware, the instrument delivers accurate electromagnetic surveys for radio facilities.

Operational receiver tuning coverage spanning 520 kHz to 5.1 MHz with 1 kHz steps
Integrated GPS receiver providing automated geo-referencing for radio field maps
Direct field intensity measurement capabilities from microvolts to volts per meter
Non-volatile memory logging and serial data interface for engineering data export

POTOMAC / Potomac Instruments SD-31 Synthesizer-Detector Systems

The portable Potomac Instruments SD-31 synthesizer-detector pairs a high-output crystal signal generator with a sensitive tuned detector. The instrument is engineered for RF bridge impedance measurements, matching network alignment, and transmission line tuning across radio sites.

High-stability crystal-controlled RF signal generator delivering clean test signals
Narrowband tuned receiver detector providing excellent rejection of adjacent channels
Seamless integration with operating impedance bridges for antenna array alignment
Internal rechargeable battery operation inside an impact-resistant metal enclosure

POTOMAC / Potomac Instruments 1900 Series Digital Antenna Monitors

Multi-tower antenna monitors in the Potomac Instruments 1900 series (including models 1901, 1902, 1903) deliver continuous monitoring of tower current ratios and phase angles. Supporting up to 12 antenna towers, these rackmount systems feed real-time telemetry to local displays and remote links.

Simultaneous monitoring of tower current ratios and phase angles for up to 12 towers
Phase resolution of 0.1 degree providing precise directional radiation pattern control
High-contrast front panel digital readout displaying operational array telemetry
Standardized communication ports for direct linkage to remote control systems

POTOMAC / Potomac Instruments 1750-TLM Tower Lighting Monitors

Potomac Instruments 1750-TLM monitoring units safeguard obstruction lighting on tall radio masts and communications towers. The system tracks lighting current draw, instantly detects beacon or side-marker lamp outages, and triggers alarm alerts to fulfill aviation safety guidelines.

Continuous operational verification of beacon lights and side-marker obstruction lamps
Individual lamp failure detection through precise current drop threshold monitoring
Isolated alarm relay contacts for straightforward connection into station alarms
Compliance with mandatory aviation safety standards established by FAA and FCC

POTOMAC / Potomac Instruments AA-51A Automatic Audio Analyzers

The Potomac Instruments AA-51A automatic audio analyzer performs comprehensive performance verification of studio gear, transmission chains, and audio links. Featuring automatic frequency tracking, it measures total harmonic distortion down to 0.005%, intermodulation, and noise floors.

Automatic test frequency capture eliminating manual null-balancing adjustments
Total harmonic distortion measurement sensitivity spanning 0.005% to 100%
Accurate quantification of SMPTE intermodulation products and residual noise levels
Balanced high-impedance input stages engineered for professional studio gear

POTOMAC / Potomac Instruments AG-51 Low-Distortion Audio Generators

The Potomac Instruments AG-51 laboratory audio generator produces ultra-pure sine waveforms exhibiting minimal harmonic distortion. Paired with the AA-51A analyzer, this signal source provides reference stimulation for transmitter modulation alignment and studio console verification.

Ultra-pure sinusoidal output maintaining residual distortion figures below 0.003%
Precision switched frequency stepping across the audible spectrum up to 100 kHz
Calibrated step attenuator enabling accurate output voltage level adjustments
Balanced output stage providing matched 600-ohm impedance for studio audio links

Potomac Instruments Corporate Heritage and RF Metrology Evolution

American instrument manufacturer Potomac Instruments has maintained precision engineering and manufacturing operations since 1968, when production facilities in Frederick, Maryland were established to supply test equipment for terrestrial radio and television transmitting facilities.

Over five decades of field deployment, the POTOMAC brand has earned an enduring reputation among radio transmission engineers, regulatory authorities, and telecommunications operators.

Specialized field intensity meters and antenna array phase monitors provide dependable signal quantification across demanding urban and rural propagation environments where measurement repeatability is essential.

PI-4100 Digital Field Strength Survey Instrumentation Architecture

Engineered as the digital successor to the long-standing FIM-41 industry standard, the Potomac Instruments PI-4100 unites decades of field survey expertise with modern digital signal processing algorithms.

The receiver operates across medium wave spectrum from 520 kHz to 5.1 MHz with precise 1 kHz frequency steps. An integrated global positioning satellite receiver records geographical coordinates for each field reading, enabling automated mapping of transmission patterns.

The rugged metallic enclosure houses a shielded loop antenna that protects sensitive input circuits against strong local electromagnetic fields.

RF Bridge Antenna Impedance Measurements with the SD-31 System

The Potomac Instruments SD-31 portable frequency synthesizer-detector combines a stable crystal test signal generator and a tuned selective detector within a single battery-powered unit.

Engineered for transmission line matching and RF bridge measurements of antenna input impedance across AM and HF bands, the unit delivers high frequency stability alongside superior adjacent-channel rejection.

Field engineers can isolate resistive and reactive impedance components without interference from neighboring high-power transmitters operating in dense RF environments.

Multi-Tower Directional Antenna Array Monitoring via 1900 Series

Directional multi-tower antenna systems require continuous surveillance of tower current ratios and relative phase angles to preserve assigned radiation patterns.

Potomac Instruments 1900 series digital monitors (exemplified by the Model 1901) process signals from sampling loops and current transformers across arrays of up to 12 towers.

A phase resolution of 0.1 degree ensures radiation compliance with legal operating licenses, eliminating unauthorized radiation toward adjacent geographical service areas.

Tower Obstruction Lighting Surveillance with 1750-TLM Controllers

Tall transmission masts and telecommunications towers require continuous verification of obstruction lighting systems under international aviation safety mandates.

The dedicated Potomac Instruments 1750-TLM monitor tracks electrical current across beacon flashers and steady-burning obstruction lamps on all tower tiers.

Internal logic detects individual lamp dropouts by sensing minute current shifts, closing isolated alarm relays to alert station engineering teams immediately.

Studio Performance Verification via AA-51A Analyzers and AG-51 Sources

Comprehensive verification of audio distribution networks, transmitter modulation equipment, and recording gear relies upon the paired operation of the Potomac Instruments AG-51 low-distortion audio generator and AA-51A automatic analyzer.

The generator supplies ultra-pure sine signals with residual harmonic distortion below 0.003%, while the analyzer provides rapid automated frequency acquisition without manual filter nulling. SpareX engineers assist clients with equipment selection, technical documentation, and delivery support.

POTOMAC / Potomac Instruments and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of POTOMAC / Potomac Instruments and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.