Apollo SL40 User Manual

Troubleshooting
Apollo SL40 Field Maintenance Manual
1
7
2. Set the SL40 as listed below:
While viewing the frequency display, use the large and small knob on the right
side of the SL40 to select 127.5 MHz.
Toggle this frequency into the Active channel.
Press the PTT button on the test panel.
3. Key the transmitter
EXPECTED RESULTS SNR ≥35 dB
4. UN key the transmitter
TRANSMITTER AUDIO DISTORTION
Transmitter audio distortion is measured using the HP8920. This is accomplished by
presetting the SL40 to the same channel as the HP8920. Adjust the amplitude of a 1000
Hz tone (input to MIC 1 and/or MIC 2) to obtain 85% modulation. Then select the audio
distortion function on the HP8920 Communications Test Set.
Procedure:
1. Set the HP 8920 as listed below. Use Figure 3 and Figure 4 as guides.
Press PRESET
Press TX function
Using the CURSOR control knob or the USER keys set:
AUTO MANUAL MANUAL
TUNE Freq 127.5 MHz
TX PWR 0
RF IN/ ANT RF IN
AF ANAL IN AM Demod
De-EMPHASIS off
Detector PK+-/2
AF GEN Freq 1 kHz
Set AF GEN LVL to read 85% modulation
Set AF meter to DISTN
2. Key the transmitter
EXPECTED RESULTS: DISTN < 10%
3. UN key the transmitter

Apollo SL40 Specifications

General

Brand	Apollo
Model	SL40
Category	Transceiver
Language	English