Motorola Solutions Inc. 99FT4100 Manual De Usuario

The following test equipment are required to perform the procedure:

• Aeroflex 3920 Digital Radio Test Set (or equivalent)

• Service Speaker (part no. HSN1006_)

• Station Rear Accessory Test Cable

• Dummy Load (50 Ω, repeater wattage or higher) required for repeaters only

• DB25/RJ-45 Adaptor

1 Connect equipment as shown in 

Figure 18: Test Equipment Setup for Verifying Receiver

Circuitry on page 63

.

2 Set the service monitor to generate a 1.0 μV (-107 dBm) FM signal at the receiver frequency,

modulated by a 1 kHz tone at 3 kHz deviation for 25 /30 kHz channel spacing, or 1.5 kHz
deviation for 12.5 kHz channel spacing. The 1 kHz tone should be audible through the external
speaker. If no audio is heard, suspect the following:

• Faulty transceiver board

• Faulty service monitor-to-station RF cable

• Left panel to transceiver board cable unplugged

• Faulty left panel to transceiver board cable

3 If audio is heard (the audio volume can be adjusted on the rear of the HSN1006), look at the

oscilloscope window on the Aeroflex 3920 (or a separate O-Scope).

a Verify that the audio level sine wave measures between 0.75 to 1.5 Vpp.

b If not, connect to the tuner and increase the Rx audio level until this is achieved. If the level

cannot be obtained, suspect a faulty transceiver board.

4 Move the BNC cable from the scope CH 1 input to the Audio 1 input.

5 Change System Monitor injection signal level to the noted levels in 

Table 8: SLR 1000 Repeater

Specifications on page 37

.

6 Measure the receiver 12 dB SINAD sensitivity.

a If the SINAD level is less than 12 dB, suspect a faulty transceiver board.

7 This completes the Verifying Receiver Circuitry test procedure. If all displays and measurements

are correct, the receiver circuitry may be considered to be operating properly.

a Remove test equipment, restore the repeater to normal service, and (if applicable) return to

the troubleshooting flow chart to resume troubleshooting sequence.

MN003557A01-AA
Chapter 7:  SLR 1000 Performance Check or Testing

62  

Send Feedback