Applied Instruments CATV Signal Level Meter

Applied Instruments CATV Signal Level Meter

CATV and Satellite Signal Level Meters are used to test the quality of TV and satellite signals. They are also called TV Meters, Field Strength Meters, and Satellite Finders.  These devices are primarily intended for installers and service technicians. Signal level is measured over a specified frequency range and expressed typically as dBmV or dBm.
 
Signal level meters would be connected to the cable from the antenna or cable provider. The antenna can be located and adjusted based on the signal level and other problems diagnosed.
 
Key Selection Criteria

• Signal type (CATV, VHF, UHF,DBS,MMDS,SMATV,DVB, DSS, ISDB-Tb, etc.)
• Frequency
• Spectrum Display. Some bench units will provide this feature or you can separately purchase a full spectrum analyzer from TEquipment

CATV Test Options include:

• Modem upstream level. Modems require additional verification of return path levels. This is important since certain defects in cabling or components can cause problems in the return path while not affecting the forward path. Since modem upstream signals are very complex, they cannot be measured directly by a signal level meter; upstream signals can only be reported by an actual DOCSIS modem. Consider devices with a built-in DOCSIS cable modem that automatically connects with the CMTS and reports the upstream level.
• Ingress and leakage. Forward and return services are both prone to disruption from interfering off-air signals. These off-air signals are known as ingress. Ingress enters the cable system through bad shielding; generally from loose connections, poor quality splices or damaged cables. The same fault allows forward channels to leak from the cable system; these signals are referred to as leakage signals. Consider a unit that offers both ingress and leakage test functions, which provides installer with the tools needed to quickly identify, isolate and repair any shielding problems in the home.

What does MER, BER and C/N stand for and why are they important?
These terms are borrowed from the telecom industry for signal level.

• MER is the Modulation Error Ratio
• BER is the Bit Error Ratio
• C/N Is the carrier to noise ratio or signal to noise ratio (SNR)

These are helpful to a an installer or service technician determine problems such as loose or corroded wires, too long a cable run, or problems at the ground block, multi switches, head end or tap.