TEK RFM151 SignalScoutTMCable TV RF Analyzer

Features

The Tektronix SignalScout^TM RFM151 is a high-performance RF measurement field tool tailored for analog/digital cable TV networks. It is designed to meet the demanding requirements of cable television technicians performing troubleshooting and maintenance operations anywhere in the network. The Cable TV RF Analyzer RFM151 provides all of the basic signal level measurement capabilities, plus spectrum analysis, ingress and digital channel RF measurement capabilities not available in comparable products.

The RFM151's stepped integration method efficiently and accurately delivers the true average power of QAM, QPR, QPSK or VSB digital channels. Unlike single-point measure and calculate methods, the stepped integration technique takes into account signal abnormalities such as un-flatness.

The Peak Analog-to-Digital Average Power Level Difference measurement makes short work of verifying power loading in mixed analog and digital systems. Use it to set digital modulator levels referenced to the analog carriers.

The Desired-to-Undesired Signal Ratio is an in-channel (out of service) average power-to-noise measurement that includes noise, as well as distortion signals, such as ingress and analog system-generated CSO and CTB.

The RFM151's Spectrum Mode allows technicians to troubleshoot most problems before calling for more advanced equipment. Spectrum Mode Features include:

• AM and FM demodulators
• Dual markers
• Noise marker
• Window Sweep (fast sweep)
• Max hold
• Preamp control
• Peak/average detection

Combination AM/FM demodulators with amplifier and speaker, are available both in Meter Mode and Spectrum Mode. These detectors help the technician identify both wanted signals, such as aural carriers, and unwanted signals, such as a two-way radio transmission, and other ingress.

The General Purpose Spectrum Mode offers a choice of no markers, dual frequency-amplitude markers with DELTA readout or noise markers (in dB/Hz) with selectable normalized bandwidth. Other features of spectrum mode include Window Sweep which reduces the amount of swept display, increasing the display update rate to show rapidly changing signals; Max Hold, to show only the highest value of the displayed spectrum; Selectable Peak or Average detection modes and a preamp for making low-level readings.

The RFM151 is the technician's best friend when it comes to troubleshooting ingress problems. Exclusive circuitry minimizes forward-path signals overloading the RFM151's input when measuring return-path traffic. Low-level ingress measurements can be taken in common path locations - such as a tap or seizure screw. The RFM151 is able to display return-path bursty signals and low-level ingress down to -65 dBmV (-5dBµV) to help locate the ingress source.

Another unique RFM151 feature is the Ingress Monitor Mode which allows up to 32 frequency windows to be defined within the displayed spectrum, each with its own level threshold.

When a signal violates the threshold, the instrument either stops and shows the display, stores the violation in memory or continues. Violations can be stored as frequency/amplitude/time data or complete spectrum displays with time stamps. Sweep delays can be set from 2 to 60 minutes in one-minute intervals allowing unattended monitoring.

The SignalScout RFM151 provides five different level displays: Single Channel, 5-channel, Pilots, All Channels and Meter. These display modes can show either analog or digital channel information.

The 5-channel display mode provides both a numerical reading and a bar graph display. This is great for doing system-at-a-glance measurements and looking at tilt.

The Pilots display mode shows both bar graph and numeric displays of any two frequencies used for setting the AGC in the plant.

The RFM151 also performs the following measurements: Carrier-to-Noise, Hum, FM Deviation and Field Strength. Carrier-to-Noise can be configured for either In-Service (using the guard band) or Out-of-Service (with a user-settable frequency offset). Both measurements are normalized to the proper bandwidth for the system (4 MHz for NTSC and 5 MHz for PAL).

The Relative Field Strength mode allows the user to select a frequency between 5 and 1080 MHz and use an optional antenna to locate a leak of the signal of interest. Field Strength Mode is useful for finding leaks in the cable plant and locating the sources.

The RFM151 works on any world television standard and all common transmission standards. It automatically measures the average power of a NICAM sound carrier. Just enter the correct frequency into the second aural carrier slot and the RFM151 does the rest.

The RFM151 and CSS151 Software form a powerful tool tailored to an individual cable system. By creating automatic test sequences using the CSS151 software, test time and errors are reduced. Tests can be setup to run at fixed time intervals using the interval timer in the RFM151 or under technician control. These sequences can be used for the FCC required tests including the 24-hour test or just for routine maintenance.

Data in the worksheet can be printed directly or processed into concise reports for hard copy files. Reports include a Status Report that shows how well the system is performing with regard to level differences between adjacent channels and minimum and maximum level differences. Another report shows the visual carrier level and visual-to-aural carrier difference over four six-hour time periods for monitoring system performance over time and temperature. Both reports can be printed with up to six lines of header text for displaying additional information.

• Digital Channel RF Measurement Suite Includes Average Power Level Plus Noise/Distortion Measurement
• Exclusive Ingress Monitor Mode Records Ingress Violations of up to 32 User-defined Frequency and Level Windows
• Enhanced Spectrum Mode Increases Ability to Capture Low-level and Bursty Signals
• AM and FM Demodulators with Speaker Helps Identify Ingress Sources
• User-changeable Battery Pack with Optional External Charger for Uninterrupted Use
• Control and Analysis Software Includes Ingress/Spectrum Analysis Capability and Report Generation

• Digital Channel Level and Noise Testing
• Ingress Monitoring and Troubleshooting
• Cable System Leak Tracking
• Analog Channel Performance Verification and Troubleshooting

Specifications

RF Input

Input Impedance - 75 Ohm (nominal).

Connector Type - Male type F with precision female-to-female F coupler.

Range - 5 to 1080 MHz.

Accuracy - ±5 kHz or ±10^-5 of tuned frequency, which ever is greater.

Sensitivity - -35 to 60 dBmV (+25 to +120 dBµV).

Repeatability - ±0.5 dB.

Analog Channel Select Mode - Automatic or user selectable.

Accuracy - ±2 dB.

Measurement Location - User selectable.

Accuracy - ±2 dB.

Range - Up to 51 dB with carrier amplitude >5 dBmV, modulation removed.

Measurement Location - Guard band (approximately equal to 1.25 MHz below the visual carrier).

Accuracy - ±2 dB.

Range - Up to 47 dB with carrier amplitude >0 dBmV.

Measurement Location - In channel (Out of Service).

Accuracy - ±2%.

Fundamental Frequency - 50/60 Hz, user-selectable frequency.

Range - 0 to 5%.

Accuracy - ±1%.

Accuracy - ±10% of peak deviation or ±2 kHz whichever is greater.

Modes -
General Purpose (Dual/Noise/No markers).
Demod (AM, FM detectors, speaker).
Ingress Monitor (up to 32 user-defined thresholds within a displayed spectrum).

Common Specifications -
Frequency Range: 5 to 1080 MHz.
Span/Division: 4 MHz, 2 MHz, 1 MHz, 400 kHz, 200 kHz.
Resolution Bandwidth: Span >1 MHz: 300 kHz.
Span <1MHz: 30kHz.
Sensitivity: -60 dBmV (-65 dBmV typical).
Spurious Free Dynamic Range: 20 to 1080 MHz:> -50 dBc.
5 to 20 MHz: < -40 dBc.
Detection Mode: Peak or Average.
Vertical Scales: 2, 5, 10, 15 dB/Div.
Other Controls: Preamp, max hold.

Temperature - Operating: 0 to +50°C (+32 to +122°F).
Nonoperating: -20 to +60°C (-4 to +140°F).

Humidity - Operating: 5 to 95% from 0 to +50°C.

Altitude - Operating: Up to 15,000 ft. (4,550 m).
Nonoperating: Up to 40,000 ft. (12,192 m).

DC Input Range - +10 to +15 VDC.

Power Requirement - 10 W maximum.

Battery Type - User replaceable.

Battery Life - 2.75 Hr.