HP 85027A/B/C Performance Tests
Equipment
HP 85027A
HP 85027B
HP 85027C
Sweep Oscillator
HP 8350B
HP 8350B
HP 835DB
RF plug-in
HP 83592A
HP 83595A
HP 83592A
Scalar network analyzer
HP 8757A
HP 8757A
HP 8757A
Cal. open/short
85021 -60021
85037-60001
85032-60001
50 ohm load
909A opt 012
909D
909A opt 012
Adapter*
not req’d
85027-60002
1250-1 475
*
A second directional bridge is required as a test instrument in addition to the directional bridge
under test. The adapters recommended are suitable for use with two similar bridges.
Procedure
1. Set up the equipment as shown in Figure 4-4, with the calibrated open connected to the test
directional bridge, not the directional bridge under test.
2. PRESET
the analyzer. It should indicate that Input A is on Channel 1. Turn off Channel 2. The
Preset should also preset the sweep oscillator to a sweep time of 200 ms with 27.8 kHz
modulation on.
3. Set the sweep oscillator start and stop frequencies to correspond to the first band of
frequencies in the Performance Test Record (0.01 to 8.4 GHz).
4. Perform an open/short calibration and store it in memory.
5. Connect the directional bridge under test to the first directional bridge, test port to test port
with an adapter if necessary. Connect the 50 ohm load to the input port of the directional
bridge under test.
6. On the HP 8757A turn on the cursor and press the [MAX]softkeyto find the point of minimum
return loss (highest point) on the trace. Enter this value on the Performance Test Record.
7. Repeat steps 3 through 7 for each frequency band of interest.
8. If the test results (including uncertainties) are not within specifications -as indicated on the
Test Port Match Performance Test Record, refer to the Troubleshooting section of this
manual.
Table 4-2.
Test Port Match Performance Test Record
HP 85027A
HP 85027B
HP 85027C
Frequency
Spec.
Test
Spec.
Test
Spec.
Test
Band (GHz)
Result
Result
Result
0.01-8.4
> =23 dB
______
> =23 dB
______
>
=23 dB
_______
8.4-12.4
>=l9dB
_____
>=l5dB
_____
>=19dB
_______
12.4-18.0
>=l5dB
_____
>=l5dB
_____
>=l5dB
_______
18.0-20.0
—
>=l5dB
_____
—
20.0-26.5
—
>=11 dB
______
—
Uncertainty*
>=ldB
>=ldB
>=2dB
4-8
UPDATES APPLY TO ALL SERIALS