4.2 Steps To Check The Frequency Response - ABB ETL600 Instruction Manual

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A
6. Connect the BNC connector OUT of P3LL with the RX RF-IN (50 Ohm input) SSMB connector on the
P4RX board.
7. Connect the level meter 50 Ohm (or 75 Ohm) to the RX RF-OUT (50 Ohm output) SSMB connector of
the P4RX board. Read the indicated level in dB.
• If a 50 Ohm instrument is used, designate this measured level as B.
• If a 75 Ohm instrument is used, subtract 1.58 dB from the measured level. Designate this result as
B.
8. (B-A) is the gain of the P4RX board. Now the following condition should be fulfilled:
• for F0 ≤ 500 kHz:
• for F0 > 500 kHz:

4.2 Steps to check the frequency response

Refer also to chapter 5 "Test circuits", Figure 2.
1. The Tx tuning adapter P3LL is inserted in place of the RF hybrid (P3LE).
2. The P3LL tuning adapter is set for the following for the entire process:
• FUNCTION
• Position of S1
• Position of S2
• Position of S3
• Position of LOAD
3. The P4RX module is plugged directly into the rack.
4. Connect the BNC connector OUT of P3LL with the RX RF-IN connector on P4RX.
Connect the level meter (50 or 75 Ohm) to the RX RF-OUT connector of P4RX.
Because the P3LL output is a high impedance source, the signal level at 50/75 Ohm will be quite
small. But mostly a wide band level meter still will be sensitive enough. If not, use a more sensitive
selective level meter to get reliable
5. In the Tuning Rx RF filter dialog box, click Check Rx RF filter to get the dialog box Check filter.
6. Click Activate f0 – 0.5 · B
check the pass condition given in dialog box.
7. Click Activate f0 + 0.5 · B
check the pass condition given in dialog box.
8. If the conditions checked in steps 6 and 7 are fulfilled, the pass band ripple of the filter is within
specifications
9. With the next tests, the filter selectivity is checked.
Click Activate f0 – 2 · B
check the pass condition given in dialog box.
10. Click Activate f0 + 2 · B
check the pass condition given in dialog box.
11. If the conditions checked in steps 9 and 10 are fulfilled, the selectivity of the filter is within
specifications
12. Click Deactivate frequency and Close.
13. Click Cancel.
14. Remove tuning adapter P3LL and insert the RF hybrid (P3LE) back into the rack.
(B-A) = 0 dB ±1.5 dB
(B-A) = 0 dB +1.5 dB / -3.0 dB
Note:
The RF hybrid must not be plugged on top of P3LL.
A
L2
FILTER
Don't care
Don't care
measurements.
(B = 4, 8, 16 or 32 kHz). Measure the voltage at RX RF-OUT in dB and
Rx
Rx
(B = 4, 8, 16 or 32 kHz). Measure the voltage at RX RF-OUT in dB and
Rx
Rx
(B = 4, 8, 16 or 32 kHz). Measure the voltage at RX RF-OUT in dB and
Rx
Rx
. (B = 4, 8, 16 or 32 kHz). Measure the voltage at RX RF-OUT in dB and
Rx
Rx
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EN 5/7
1KHW001491-EN