Wandel & Goltermann RM-5 Communications Test Set
Hersteller:
Modell:
RM-5
Datum:
1982
Kategorie:
Gruppe:
Beschreibung:
Radio-Link Measuring Setup 35/70/140 MHz

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The most frequently used radio-link IF is 70 MHz, but IFs of 35 MHz and 140 MHz are gaining in popularity. Systems with a small number of channels use 35 MHz; 70 MHz 1s used by systems having up to 1800 channels. Analog systems with 2700 channels use a 140 MHz IF; in the future this IF will be used by digital radio-links operating at high bit rates, and by satellite links using TDMA. The RM-5 can handle all three frequencies. The RM-5 comprises a separate Generator section, the RMS-5, and a receive section, the RME-5. The RM-5 is the simple way to measure total baseband distortion, the results are clear and easy- to-read. The RM-5 cart also be used to measure various kinds of distortion between IF ports, and also modulator, demodulator and IF Filter distortion. All these facilities are essential if faults are to be located, and the whole system as well as each system component are to be optimally aligned. A test modem is essential if basic noise, intermodulation products, or the BB-B8 frequency response between IF ports, are to be measured on wideband radio-link systems. The test modem is available as an option. In many applications the "noise calculation” option can be used instead of the test modem. Using IF-IF differential phase and differentia] gain results, the option calculates the intermodulation noise in three 8B test channels. All relevant system parameters are used for the calculation. The RM-5 is also ideal for test depts. that are planning to introduce automated testing to cope with a large number of test items, or are looking for a better and more logical way of checking batches containing different items. All the RM-5's Generator and receive functions can be remote-controlled via a standard IEC 625/IEEE 488 Interface. This means that the RM-5 can be easily integrated into automated test systems. Because the RM-5 has very low test frequencies (from 25 kHz], it is possible to test FM or PM systems having a small number of channels. However, to ensure’that all faults can be detected, the RM-5 also has test frequencies up to 5.6 MHz. These frequencies can also be demodulated in the RM-51s receive section. A facility that automatically reduces the sweep witdh prevents incorrect results. Extreme accuracy, especially at high frequencies, is essential for performing IF-IF distortion measurements. Double modulation of and on the send-side, and tracking demodulation on the receive-side ensure the RM-5 has the required accuracy. The modern design of the RM-5 makes it reliable and easy-to-operate. The Generator section and the receive section are operated by buttons. Test parameters can be set very accurately. The RMS-5 Generator displays all the most important transmit parameters by means of a multi - digit 7-segment LEO. The parameters can be set by means of up/down keys. Frequently used setups can be stored and called up when required. An integral battery ensures that memory contents are not lost when the RM-5 is switched off. Because the Generator section is automatically tuned to the test frequency, end-to-end measurements are easy to perform. The sensitivity of the receiver is automatically adjusted to handle a range of signal levels. This facility operates at the IF and BB frequencies. A new way of displaying results on the RME-5 has been adopted. The display unit can now show curves and alphanumeric results simultaneously in certain areas of the screen. This means sweep traces can be read and understood at a glance, and that any photos or printouts of the results can be fully documented for use at a later date. The RME-5 has a "monitor" output for printing out the results on the screen. The IF level at the centre frequency and the test deviation are shown on the screen, so that the operator always knows if the test parameters are correct. The IF centre frequency and the sweep width are determined by an integral frequency counter; these parameters are also displayed on the screen. A further feature which should be mentioned is the facility for displaying two sweep curves on the screen simultaneously. In other words, ary pair of results (¿31, ¿Jtf and ¿3U/UQ^, IF-IF frequency response and return loss) can be selected via a pushbutton. The calibrated ranges for the distortion parameters and the frequency response measurements can be set by means of up/down keys. The RM~5‘s display capability and facilities for evaluating sweep traces are greatly enhanced by microprocessor control. The frequency markers are now a pair of variable line cursors that are symmetrical about the IF centre frequency (i.e. the vertical line through the centre of the screen). Noisy traces, which often occur when measurements are made via satellite, can be smoothed and made easier to read by means of a noise averaging facility. Five averaging factors are provided to handle signals with various degrees of noise. To eliminate the intrinsic distortion of the RM-5 or to adjust an item-under-test so that its characteristics follow a given curve, it is possible to store a reference curve and the difference curve obtained by subtracting the test curve from the reference curve. The RM-5 has special facilities for analysing distortion curves. The linear component and the quadratic (parabolic) component of the curves can be calculated over any frequency interval. In the "Bessel spectrum" operating riwde, the receiver displays the frequency-modulated input signal as a spectrum - which means the RM-5 can be used as a spectrum analyser. This mode can also be used to calibrate the test frequency deviation meter in the RM-5 and to set the sensitivity of modulators and demodulators. To set the IF centre frequency of modulators, you can obtain a display with higher resolution by selecting the frequency Counter mode on the RME-5. Instead of the <IEC 625> Interface board for remote controlling the Rf€-5, it is possible to fit an x-y plotter Interface that will only allow you to print out sweep curves. The RM-5 also has an option for generating all the INTELSAT IF-IF frequency response and IF-IF group delay tolerance masks that are used for lining-up earth stations and satellite communications paths. One keystroke selects the mask you want. The RM-5 is an up-to-date Test Set that can handle many complex applications but is nevertheless easy to operate.

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Bedienungsanleitung
Dokumenttyp:
Bedienungsanleitung
Seiten:
220
Größe:
9.66 Mbytes (10130767 Bytes)
Sprache:
english
Revision:
Dokument-ID:
BN 0916
Datum:
1982 01 01
Qualität:
Gescanntes Dokument, teilweise schwer oder teilweise nicht zu lesen.
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2017 01 22
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BN 916, series D onwards Operating Manual

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