User guide

DM-14B & DM-14C User’s Guide
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• PICTURE: spectrum with outlines only or full white
• ∆ MARKER: freq./level difference between two signals and C/N measurement
• MARKER BW: to adjust filters, amplifiers, etc. and to measure digital power in SPECT mode “BW–PWR”.
• MAX HOLD: peak memory. Maintains the max. peak reached during a series of measurements
• DC at RF in: output power supply (5, 12, 15, 18, 24 V – OFF).
• LNB L.O.: local oscillator.
• BUZZER: ON/OFF activates an acoustic sound which varies with the signal level or digital satellite quality.
17) EMULATED COFDM/QAM DIGITAL TV MEASUREMENTS (DEMODULATED MEASUREMENTS:
COFDM supplied, QAM optional): These allow you to carry out perfect average power and C/N measurements,
provide a BER evaluation and the quality of the signal (FAIL–MARGINAL– PASS).
HOW THE EMULATED DIGITAL MEASUREMENT WORKS: The signal is measured in RF based on the
C/N measurement and multiplex flatness. Thanks to a series of special algorithms, defined and registered by
ROVER in co–operation with some UK DTG (Digital Terrestrial Group) engineers in 1998 and later optimised, it is
possible to provide a good signal evaluation in both cases of adjacent and non–adjacent channels (selectable n/f –
near/far) without demodulating the digital signal. The measurement accuracy is very high, except in rare cases of
interference completely hidden under the digital multiplex spectrum.
18) LNB-POL & DiSEqC: as you have already seen, there are two different settings, which make the instrument the
most complete and easiest to use in the world:
• LNB: OFF, VERT HIGH, VERT LOW, HORIZ HIGH and HORIZ LOW Polarization
• DiSEqC: off–a–b–c–d, the combination of these two parameters enables you to select the various multi-switches
with 4 cables “a”, 8 cables “b”, 12 cables “c”, 16 cables “d”.
19) You can obtain other very interesting spectrum functions with your instrument if you connect it to an optional noise
generator, for example the “CNG–80” or “CNG–70”:
• Scalar network analyser (wobulator), in “MRK BW” spectrum function, for the calibration and test of channel
filters, amplifiers, splitters, traps, outlets, coaxial cables and relevant VSWR or R.L. measurement of standing
waves ratio (with a reflect meter bridge).
• Coaxial cable reflect meter (“∆ MRK” spectrum function) to measure the distance of a short circuit or
interruption in coaxial cables (using a "T" connector and slide rule).
20) RESET: if the meter stalls and you are unable to turn it off, keep the ON key pressed for 10 secs and the instrument
will immediately restart. If you find that the instrument always blocks in the same situation, please contact the
manufacturer and you will be given, as an award, a year's service free of charge in addition to the standard one.
21) SOFTWARE UP–GRADE: As you well know, another excellent function of this meter is the possibility of up–
grading software free–of–charge via internet. To carry out this operation, consult Rover Instruments web site
(www.roverinstruments.com) and/or contact the service in your country.
22) START–UP MENU: this appears for two seconds every time you turn on your instrument and contains all the
information necessary for the service technicians in the case of repairs or software up-grades via internet (you can
find the same data in the SPECIAL, SELF TEST Menu).
23) We suggest turning off the meter when connecting or disconnecting the RS232 interface.
24) It is possible to store separate or mixed multi–standard plans (e.g. France/Europe or China/Hong Kong) according to
your requirements.
25) The instrument is supplied with interchangeable input connectors “F”, “BNC”, “IEC” or “N”.
26) If the TV signals are weak, or have lots of interference, and you have difficulty in tuning the TV pictures, exclude the
OSD and reactivate it, this operation should help you to tune TV pictures.
27) If the words on the screen do not tune during the frequency tuning of analogue TV and SAT programmes, briefly
remove the signal from the RF input and the words should stabilize.
28) If the instrument loses the vertical sync., with TV and SAT analogue pictures, press MENU and check that it is set to
the correct standard: 50 Hz PAL-SECAM and 60 Hz NTSC.
29) To eliminate the MENU words, press the MENU key.
30) Linear bar chart for level/power with memory & digital quality, e.g. QPSK, these are available in MEAS level 2.