PERFORMANCE TESTS
REMARKS:
This test is a more comprehensive test then the high-level, mid-level, and low-level
accuracy tests.
If the UUT fails this test, the UUT needs to be calibrated (Section 3) or repaired
(Section 6).
If the UUT fails this test at higher levels, problems with the A8 Output PCA, the A21
Attenuator PCA, the A7 Relay Driver PCA may be indicated.
If the UUT fails this test at lower levels, a problem with the A21 Attenuator PCA, the
A7 Relay Driver PCA, or an RF-leakage problem with the attenuator assembly is
probably indicated. Check for loose connectors, loose screws, improper gasketing, or a
broken feed-through filter.
Because of operational subtleties in measurement receivers and the intent to reduce the
risk of measurement errors, the following procedure is written around the use of the
H.P. 8902A as the receiver.
NOTE
The calibration factors for the sensor module must be stored into the
measurement receiver's "Cal Factor" table prior to performing calibrated
RF power measurements. Correctly entered cal factors can be verified on
the H.P. 8902A by using special functions 37.5 and 37.6. (Refer to the H.P
8902A Owner's Manual.)
PROCEDURE (Level Measurements):
1. Perform the power meter "zero" and "self-calibration" for the measurement
receiver. (Refer to the H.P. 8902A Owner's Manual.)
2. Connect all instruments as shown in Figure 4-2.
3. Program the UUT to SPCL 909, 10 MHz, +13 dBm, and AMPL STEP 6.1 dB.
4. Program the Measurement receiver to RF-POWER mode, and toggle the
LOG/LIN button to display dBm. To enable the correct cal factor selection, tune
the internal LO. on the measurement receiver to that of the UUT RF output (10
MHz V for the first frequency).
5. Step the UUT level from +13 dBm to -11.4 dBm using the STEP key.
Verify that each level measured with the measuring receiver agrees with the UUT
programmed level and is within ±1.5 dB.
6. Select TUNED-RF LEVEL on the measuring receiver, wait for a displayed
reading, then press the CALIBRATE button. Verify that the Recal annunciator
goes out and a stable reading is displayed again.
7. Step the UUT from -11.4 to -127.3 dBm, again observing that each stepped level is
within ±1.5 dB.
4-11
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