Checkout Procedure; Introduction; Test Equipment Required - Motorola R-2001A Service Manual

5-125. Spectrum Analyzer
1. Select the Monitor Function and the Spectrum Analyzer Display on the R2001A. Set the monitor
frequency to 250 MHz, and the RF Step Attenuator to the 40 dB position.
2. Connect the external signal generator to the RF In/Out Jack on the front panel. Adjust the external
generator for a center frequency of 250 MHz and a calibrated output level of -30 dBm with no
modulation.
3. Adjust in succession C2, C83, C88, and C96 (Marked on the Receiver Test Cover) to maximize the
amplitude of the spectral line in the center of the CRT display.
4. Adjust R124, R91, and R100 (Marked on the Receiver Test Cover) to obtain a uniform change in the
spectral amplitude per 10 dB change of the RFStep Attenuator. R124 affects the level of the spectral
component when in the top quarter of the screen, R91 affects levels in the third quarter from the top,
and R100 affects levels in the bottom quarter.
5. Adjust R119 for offset and R121 for gain sothatwiththestepattenuatorintheOdBPositionthepeakof
the spectral line lies on the 30 dB line of the CRT and that successive step increases of the input
attenuator move the spectral amplitude downward in 10 dB increments on the CRT. The accuracy
required for any one step attenuator position is ±3 dB.
6. It will generally be necessary to repeat paragraphs 5-125.4 and 5-125.5 until the best possible accuracy
is obtained.
7. Turn the power off and remove the Receiver Module and the Receiver Extender for the chassis.
Remove the Test Cover from the Receiver Module and replace the module cover. Reinstall the Receiver
Module into the system chassis.
5-126.

CHECKOUT PROCEDURE

5-127. Introduction

5-128. This section provides a system checkout procedure. This procedure will help isolate system failures
when used with the troubleshooting information in para 5-146.

5-129. Test Equipment Required

5-130. The test equipment listed in table 5-5 or its equivalent will be required to perform the checkout
procedure.
*RF Signal Generator
"RF Power Meter
*SINAD Meter
"Modulation Meter
RF Power Source
*An R2001 A is suitable for use in place of these separate equipments.
Table 5-5. Test Equipment
5-32
Motorola R-1201A
Motorola S-1339A
Motorola R-1013A
Boonton 82AD
1 watt to 100 watts