quency translation. Channel stepping can be performed by defining

an increment and then using the FREQ

keys. This is particular-

ly useful when testing multi-channel systems.

Live Look and Listen

This feature puts the 2948 above all of its peers with the ability to

examine signals on the screen and demodulate them simultaneously.

Intermittent interference can be isolated quickly and the signals then

easily identified. The trace can be saved to memory card along with

the time and date, providing factual evidence that can be recalled

later. This feature is particularly useful when looking for rogue trans-

missions, especially on busy base station sites.

From 2 µV to 150 Watts

The 2948 measures the power of low level signals such as those

encountered when monitoring off-air signals or those found when

probing a circuit. 150 Watts measurement is provided without the

need for external attenuators, so the high power of base stations can

be measured directly. Measurement accuracy of better than 10% is

guaranteed all the way down to 5 mW on the N-Type connector, allow-

ing cellular radios to be qualified at low power levels.

Accurate RF Signals

The signal generator provides coverage from 400 kHz to 1.05 GHz

with +5 dBm output (+7 dBm overrange) and fast switching speed.

Level accuracy is ±2 dB at all levels above -127 dBm.

Duplex - provided as standard

Full duplex operation is provided by the 2948. This allows testing of

duplex radios as well as simultaneous testing of repeater transmit and

receive paths. There are no restrictions to the duplex offset.

Cellular and Trunking - built in

AMPS, TACS and NMT analog cellular standards are available inter-

nally, with all country variants provided in each package. Trunking for

MPT 1327/1343 and variants of them is also available.

A new trunking capability has been added with the introduction of

EDACS™ Radio and Repeater test capability.

Remote control of the inbuilt tests is provided, so that measurements

can be started and results logged automatically.

Network Simulation

The 2948 simulates the signalling protocol that the radio would see

from the real network. This allows calls to be set up and handled

enabling receiver and transmitter parametric measurements to be

made.

Remote Control - RS-232 or GPIB

Remote control is provided, with an RS-232 interface as standard. An

IEEE-488.2 interface (option 5) can be fitted where other instru-

ments are required to operate in a system with the 2948.

Printing Made Easy

With the parallel printer port interface, screen dumps, automatic test

results or previously stored results may be sent to most parallel print-

ers. These facilities are available as standard using the serial

RS-232 interface.

A screen capture facility is available so any screen displayed on the

2948 can be saved direct to a PC via the serial port as a bit map file.

Autorun - internal control

With the Analog Systems Card fitted, automatic testing without an

external controller is possible. Custom tests may be written and run

by the operator. Four programmable relay contacts are provided with

the optional parallel printer interface. This allows remote control of

radios or test fixtures from built-in automatic tests.

Custom Programs

Users may program the instrument to suit their own specific needs.

This is possible either by configuring any of the 4 built-in programs

or by using the MI-BASIC interpreter to produce a customised test

program that can be executed internally, without an external con-

troller.

Memory Card - with real time clock

The memory card drive meets the PCMCIA standard format for PC

cards. The 2948 provides a DOS based filing system that allows trans-

fer of information to a PC fitted with a memory card slot.

Test setups, test results, screen dumps, spectrum analyzer co-ordi-

nates and test sequences can all be stored on the memory card, allow-

ing information to be easily stored and retrieved when required.

Reliability

The 2948 features high integration and a chassis designed to max-

imise mechanical protection.

Audio Analysis

A comprehensive range of filters are provided as standard, including

band pass, low pass and high pass. Optional filters are available for

psophometric weighting of audio signals and demodulation of signals

in a simulated radio channel bandwidth.

The direct measurement of CTCSS is possible with the 300 Hz LP

filter, even with speech present.

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