Product Info

PTR for VHF-4000 and VDL-2000 Data Radios
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©2000 Rockwell Collins, Inc Page 33 of 61
Production Limit:
<= 6 dB variation 300 to 2500 Hz, –30 dB or
less at 3200 Hz
CMM Limit:
<= 6 dB variation 300 to 2500 Hz, –30 dB or
less at 3200 Hz
7.2.2.8 MICROPHONE BIAS
1) Set the UUT discrete inputs to “standard discrete configuration”.
2) Set the ARINC control data to “Standard 25 kHz ARINC Configuration”.
3) With no audio applied, ground the PTT line and measure open circuit voltage at mic audio input hi
(Pin 54 VHF-4000, Pin 4 VDL-2000).
4) Unground the PTT line.
Production Limit:
16.0 ± 1.5 Vdc.
CMM Limit:
16.0 ± 1.5 Vdc.
7.2.2.9 SIDETONE
1.2.9.2.1. SIDETONE FREQUENCY RESPONSE
1) Set the UUT discrete inputs to “standard discrete configuration”.
2) Set the ARINC control data to “Standard 25 kHz ARINC Configuration”.
3) Tune UUT to 126.500 MHz.
4) Connect the combined audio out (pins 25 and 26 VHF-4000, pins 31 and 19 VDL-2000) to the
distortion analyzer.
5) Apply 0.125 Vrms at 1 kHz signal to the mic audio input
6) Ground the PTT line.
7) Obtain a 0 dB reference on the audio analyzer.
8) Set the modulating frequency to 300, 1000, and 2500 Hz, verify the change in the audio out level
measured on the audio analyzer.
9) Unground the PTT line.
Production Limit:
<= 6 dB.
CMM Limit:
<= 6 dB.
1.2.9.2.1. SIDETONE DISTORTION
1) Tune UUT to 126.500 MHz.
2) Connect the Sidetone audio out (pins 20 and 26 VHF-4000, pins 31 and 19 VDL-2000) to the
distortion analyzer.
3) Apply 0.25 Vrms at 1 kHz to the mic audio input
4) Ground the PTT line.
5) Measure and verify the audio output distortion
6) Repeat using 300, 1000, and 2500 Hz at mic audio input.
7) Unground PTT
Production Limit:
<= 7%.
CMM Limit:
<= 10%.