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AM5(e) Classic Instruction Manual
6.1
MEASURE LEVEL AND FREQUENCY (LEVEL FREQ)
To measure level and frequency, an auto-ranging amplifier, average detector, and
frequency counter are connected to the signal. A 120 kHz low-pass filter is used for full
bandwidth operation. (In the -200 kHz models a 200 kHz filter is used). The detected
average voltage is converted to dBm, based on the impedance selected for the RX line.
To display the measured level and frequency, select MEAS with the DISPLAY key. If
the incoming level is 1004 Hz at a level of –10 dBm, the display will appear as shown
below.
SEND
MEAS
DISPLAY
If there is power line interference present on the circuit that could interfere with the
measurement, select the 60 Hz filter by pressing the right FILTER key so the 60 Hz LED
is lighted.
NOTE: None of the filters, selectable by the left FILTER key, apply to the Level
and Frequency measurements; their LEDs are not lighted.
If high frequencies are of no interest, use the narrow band
measurement function described in the next sub-section.
6.2
MEASURE LEVEL AND FREQUENCY,
NARROW BAND (L/F 15 kHz or L/F UNWTD)
This is a level and frequency measurement which includes a low-pass filter in the
measurement circuits. It is useful for making measurements on voice-band circuits
where high-frequency components are of no interest or could interfere with
measurements. The filter has the following characteristics:
•
AM5 Classic
•
AM5e Classic
6.3
MEASURE IDLE LINE NOISE (NOISE)
The Noise selection is a high-gain measurement of level only. It is designed to make
"Idle Line" measurements. Level is displayed in the left display window, and the right
window is unlighted. Noise measurement range and accuracy are as follows:
•
AM5 Classic
•
AM5e Classic
November 19, 1997
(18-0047)
dB
dBm
dBrn
mSEC
HOLD TONE
15 kHz low-pass
Low Frequency (Sound) Unweighted 30 Hz to 20 kHz
10 to 20 dBrn at ±2 dBrn; 20 to 100 dBrn at ±1 dBrn with CMSG
filter selected.
80 to -70 dBm at ± 2 dBm; -70 to +10 dBm at ±1 dBm with
PSHO Filter selected.
Page 6-2
MEASURE FUNCTIONS
LEVEL
FREQ
KHz
SEC
MIN
CNT
AM5e
AM5
L/F
L/F
15kHz
UNWTD
NOISE
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