Performing a Final System-Level Check

When and where to use:

The final system level check must be performed for every channel in the system to confirm that the output levels for each site are no more than 0.3 dB of each other for each of the remaining test frequencies.

Procedure:

Make several photocopies of Recovered Level Entry Log. This table serves as a log for recovered signal levels at various test frequencies. The data entered is used to check and verify system alignment.
Set up either the Service Monitor or the DSA to produce sine wave output and set the frequency to 20 Hz.
On the CSCI, disable PL/DPL by closing SW100-2 (Mute PL/ DPL). The green LED on the CSCI changes from illuminated to blinking.
Connect the Service Monitor or DSA output to CSCI. The CSCI requires a bantam plug.
Log in to the TeNSr channel bank of the station under test.
From the Main window of the DSM-II channel under test, press the T key to enter the Test window.
Place the DSM-II port for the channel under test into test mode as follows:
1. Select the desired port by placing the cursor over the TEST field of the desired port. Press Enter.
2. At the bottom of the window, on and off options appear. Move the cursor over the on option. Press Enter.
3. Press the S key to save changes. The port under test is now in the test mode.
For the DSM-II port feeding the remote base radio (DSM-II programmed as rem, loopback, or sl-lb), key up the base radio as follows:
1. From the Test window, use the arrow keys to highlight the E1 field of the selected port. Press Enter.
2. At the bottom of the window, norm, on, and off options appear. Move the cursor over the on option. Press Enter.
3. Press the S key to save changes. The E1-Lead is enabled for this port.
  
  NoteIn the following steps, the reference value recorded during the Performing Fine Amplitude Adjustment procedure ( 8) is required as a reference.
Observe the reading on the DSA.

NoteIn 9 through 11, verify that the output of the CSCI and the optimization receiver exhibit a clean sine wave. Also verify that the modulation is approximately 60%.
In the copy of Recovered Level Entry Log that is used for your system log, enter the 20 Hz reference level obtained in Performing Fine Amplitude Adjustment.

Set the frequencies and note the levels as follows:

Set the frequency of the generator to 15 Hz.	Note the level recovered from the optimization receiver. Enter this level in the 15 Hz column of the Recovered Level Entry Log for the site.
Set the frequency of the generator to 12 Hz.	Note the level recovered from the optimization receiver. Enter this level in the 12 Hz column of Recovered Level Entry Log for the site.
Set the frequency of the generator to 10 Hz.	Note the level recovered from the optimization receiver. Enter this level in the 10 Hz column of Recovered Level Entry Log for the site.
Set the frequency of the generator to 7 Hz.	Note the level recovered from the optimization receiver. Enter this level in the 7 Hz column of Recovered Level Entry Log for the site.
Set the frequency of the generator to 5 Hz.	Note the level recovered from the optimization receiver. Enter this level in the 5 Hz column of Recovered Level Entry Log for the site.

Set to E1-lead that was enabled in 8 to norm. Key up the next base radio at the next site as described in 8.
Repeat 5 through 12 for all sites in the system.
Re-enable the checked channel and disable the next channel to be measured.
Repeat 2 through 14 for all channels in the system.

NoteThe output of the CSA begins to drop when the frequency generated falls below 10 Hz. This drop causes the roll-off seen in the chart and is acceptable.
Verify that for each given frequency, the levels recorded in the Recovered Level Entry Log table are no more than 0.3 dB different for each site at a given frequency.
The MOD COMP waveform, as displayed on the CSA, should appear as a square wave with a rising edge that transitions into a flat upper level with no humps or dips.
- A hump indicates that the low frequency (5 Hz, 7 Hz, 10 Hz) levels are hotter than the levels at the higher frequencies (12 Hz, 15 Hz, 20 Hz). Decrease the MOD COMP level.
- A dip indicates that the low frequency (5 Hz, 7 Hz, 10 Hz) levels are decreasing too rapidly relative to the levels at the higher frequencies (12 Hz, 15 Hz, 20 Hz). Increase the MOD COMP level.