Tektronix 1L40, Инструкция по эксплуатации

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Operating instructions— Type 1L40
RF INPUT— Coaxial receptacle which connects through
either a Coaxial M ixer and low loss coaxial cable to the
signal source or (if above 12.4 GHz), through a Waveguide
M ixer Adapter and a two-foot coaxial cable to one of
three W aveguide Mixers which connect to the signal source.
See Signal Applications.
Signal Application
The frequency of an RF signal determines how it w ill be
applied to the RF INPUT. Signals in the frequency range of
1.5 GHz to 12.4 GHz are applied through a low loss coax­
ial cable, such as RG-9B/U, to a Coaxial Mixer Assembly
which is installed into the input receptacle. Signals in the
12.4 GHz to 40 GHz range are applied to an external
W aveguide Mixer which connects through a two-foot coax­
ial cable and a W aveguide M ixer Adapter to the input
receptacle. The W aveguide M ixer Adapter replaces the
Coaxial M ixer Assembly in the input receptacle.
Mixers and accessories may be ordered separately as
required. The selection of mixers and adapters for the fre­
quency coverage is as follows:
1.5 GHz to 12.4 GHz — Plug-In Coaxial Mixer, Tektronix
Part No. 119-0096-00.
12.4 GHz to 40 GHz— W aveguide Mixer Adapter, Tek­
tronix Part No. 119-0104-00; Coaxial Cable, Tektronix Part
No. 012-0115-00 and one of the following W aveguide.
Mixers.
Band W a v e ­
guide
(El A
d e sig na ­
tion )
Frequency
Range
Flange
Type
T ektronix
Part
Num ber
Ku
WR62 12.4 GHz to
18.0 GHz UG-419/U 119-0097-00
K WR42 18.0 GHz to
26.5 GHz
UG-595/U 119-0098-00
Ka WR28
26.5 GHz to
40.0 GHz
UG-599/U 119-0099-00
The Mixer Adapter or Coaxal Mixer may be removed
from the input receptacle by turning the retainer ring in
either direction. To replace either assembly, push the
adapter or coaxial mixer against the spring until the flange
bottoms, then turn until the latch snaps to hold the unit in
place.
Signal input power to the analyzer should not exceed
— 30 dBm. Signals above this level overload the 1st mixer
a n d /o r the 1st IF stage and generate spurious' signals on
the display. Add at least 10 dB of attenuation to the input
when the signal begins to compress (no increase of signal
amplitude wth an increase of signal level). A conversion
chart (Fig. 2-5) may be used to calculate input signal level.
CAUTION
Signals stronger than + 1 5 dBm a p p lie d to the
in p u t o r mixer w ill dam age or burn o u t the mixer
diodes.
Mismatches between the signal source and the RF INPUT
connectors may be caused by signal source output imped­
ance, long coaxal cables, etc. These mismatches w ill ad­
versely affect display flatness. When optimum flatness is
desired and signal strength is adequate, a 50Q attenuator
pad of approximately 6 to 10 dB should be added between
the signal source and the input to the mixer. The addition
of the attenuator w ill minimize reflections and optimize
display flatness. '
NOTE
Q u a lity o f a tte n u a to r used is o f v ita l im portance.
It is suggested th a t a ttenuators such as Tektronix
Part Numbers 0 1 1 -0 0 8 5 -0 0 (1 0 d B ), 0 1 1 -0 0 8 6 -0 0
(2 0 d B ) and 0 1 1 -0 0 8 7 -0 0 (4 0 dB ) or e q u ivale n t
be used.
FIRST TIME OPERATION
Preliminary
If the instrument has not been installed into the plug-in
compartment of the oscilloscope as directed under Installa­
tion, proceed as follows:
a. Set the Sweep Voltage selector at the rear panel (see
Fig. 2-4) to the correct position (100 V or 150 V) for the
oscilloscope being used. Some Tektronix Oscilloscopes and
their sweep voltage output are listed on the back panel of
the instrument. If your oscilloscope is not listed, check the
specifications given in the oscilloscope instruction manual
for the voltage swing of the sawtooth out signal.
Fig. 2 -4 . Rear panel o f the Type 1L40 showing saw tooth selector.
b. Insert the Type 1L40 into the plug-in compartment and
fasten the securing latch.
c. Turn on the oscilloscope power, connect a patch cord
between the Oscilloscope Sweep output and the Type 1L40
SWEEP INPUT connector. A llow approximately 20 minutes
warmup period for the instrument operation to stabilize.
d. Set the Type 1L40 and plug-in oscilloscope front panel
controls as follows:
DISPERSION RANGE M H z/C M
DISPERSION— COUPLED Controls coupled together
RESOLUTION and in the lO M H z/cm
position
2-6