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|  MIL-R-23016(Wep)
3.2.9.14.3.2 Broadband Intermodulation:
The test sample receiver shall be connected to the standard-
impulse generator by means of 150-ohm coaxial cable terminated
with a 10-db resistive pi or T pad with negligible frequency
characteristics in the region of the frequency of test. The
impulse generator shall be turned on and the output attenuator
reading for minimum preceptible receiver output, or other
evidence of normal function, shall be noted. The receiver
local oscillator (or each oscillator in turn for multiple-
conversion superheterodyne receivers) shall be disabled and,
if feasible, a 60-cycle voltage (or current) equal to the
oscillator signal shall be injected into the mixer. The output
of the impulse generator is then raised until the minimum
perceptible receiver output, or other evidence of normal func-
tion, is again evident. This generator setting in db, less
the original setting in db, is the broadband intermodulation in
db. The intermodulation of undesired signals introduced across
the antenna terminals shall be at least 25 db.
3.2.9.14.3.2.1 Impulse Generators:
Impulse generators used for intermodulation testing of
receivers shall be as shown in table III.
3.2.9.14.4
Receiver Front-end Rejection:
Front-end rejection of receivers shall be equal to or greater
than the limit shown in figure 29 except that image frequencies
above 25 mc. shall be 50 db. This test shall be performed with
any signal generators equipped with an accurate attenuator and
capable of a signal output at least 80 db greater than the
minimum signal perceptible at the tuned frequency of the
particular receiver being tested. If necessary, matching net-
works shall be used to obtain a 50-ohm output. All measurements
shall be corrected to account for any changes in output voltages
owing to addition of matching networks and shall be equal to
the open-circuit voltage at the output terminals. With the sig-
nal generator and receiver connected with a 50-ohm coaxial cable
and tuned to the same frequency, the generator setting which
gives the minimum perceptible reading above the receiver back-
ground noise shall be noted. Modulation may be used in conjunc-
tion with an output meter if the receiver is not equipped to
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