The 6040 Selective Level Meter is a portable field or bench
instrument designed to make precision measurements of both
level and frequency on frequency division multiplex (FDM)
equipment baseband signals. The level range of the instrument
is —99.9 dBm to 20.9 dBm with 0.1 dB resolution. The frequency
range is 300 Hz to 3.5 MHz with a signal counter accuracy of
better than 4 x 10””^in either the 10 Hz fast update mode or the
1 Hz 2 second update mode.
Although its primary application was intended to be on high
density long haul microwave systems, the 6040 may be employed
on any communications equipment requiring selective
level or frequency measurements.
1.2 ELECTRICAL FEATURES
The key electrical features of the 6040 selective level meter
are as follows:
• Level Accuracy — ±0.2 dB at carrier frequencies provides
the precision required to do end-to-end line-ups on high
long haul microwave systems. Accurate measurement on the
full range of customer test point configurations can be
with the 6040 because this instrument compensates for
bridging and impedance errors.
• Auto Level Ranging — is provided to allow the technician
to make rapid signal search measurements since the instrument
automatically selects the appropriate range for any signal
The level range may also be manually selected.
• AFC Tuning — automatically takes the tuning errors out of
your measurements. The 6040’s AFC is locked to the high
stability temperature compensated crystal oscillator module so
that each measurement is made with the tuning at the same
point on the bandpass filter, thus providing repeatable
accuracy. The AFC is also a great time-saver since no time
consuming manual tuning is required to keep signals in tune.
For measurements not suited to AFC tuning such as noise or
FSK signals, manual tuning and a high resolution analog tuning
indicator are provided.
• Precision Frequency Counter —- is built into the 6040 level
meter providing the capability of two instruments in one. The
precision frequency counter derives its reference from a high
stability temperature compensated crystal oscillator module
which provides an accuracy of 0.4 ppm. This is excellent for
testing the frequency drift on drop and insert carrier channel
oscillator and pilots. A signal count with 1 Hz resolution is
provided for the measurement of incoming signals. Other
frequency display modes provided are signal count with 10 Hz
resolution and a center passband frequency; the frequency to
which the 6040 is tuned,
• Analog Tuning Meter — In addition to the digital LEVEL
dBm display, an analog tuning meter is provided equipped with
two ranges. One range provides a 21 dB window for sweeping a
baseband for hot signals or observing noise spikes. The second
range provides a 4 dB window with an adjustable zero dB set
point to make it easy to manually tune and peak a signal with
high manual resolution.
• Level Out — A front panel BNC connector provides a
linear dBm scaled DC output to drive a recorder or oscilloscope
for an analysis of fades, noise or level troubles.
® LCD Digital Displays — of both frequency and level are
provided for high visibility. The LCD displays are designed for
high ambient temperature operation and are equipped with self
regulating heaters for low temperature operaton below 5°C.
• Field Operation — the 6040 weighs 21 lbs and is AC or
rechargeable battery powered. It has a unique battery discharge
protection feature that helps prevent running out of
battery capacity before tests are complete. At a threshold
battery voltage, LO BAT alert will flash in the LEVEL dBm
display. 25 minutes later, the 6040 shuts itself off to prevent
permanent battery damage. By momentarily switching to
POWER OFF, the protection circuit can be reset to complete