Troubleshooting Charts:
RX RF Failure
5-27
5.10 RX RF Failure – Page 1
Inject a carrier wave with - 47dBm
into antenna port. Remove shield,
SH11. Use a spectrum analyzer
and high-impedance RF probe to
measure the IF signal at the input
side of C601 going to the Abacus.
IF Frequency =
109.65 MHz?
Poor RX
sensitivity
or no RX
No
No
Is the IF signal level at the
input side of C601 about:
700: -50 dBm?
800: -55 dBm?
UHF1/UHF2: -50dBm?
VHF: -50 dBm?
Yes
1
Yes
Remove shield, SH8 and SH10. Measure RF levels
at the input side of L1117 and the input side of :
C2305 (for 7800 radios) or
C2605 (for UHF1/UHF2 radios) ,
C2705 (for VHF radios) ,
Compute the Harmonics Filter and Antenna Switch
loss.
Loss < 1.5
dB?
Remove shield SH8 and SH10.
Visual inspect the Harmonics Filter
and Antenna Switch components and
replace parts if needed.
No
Measure RF levels at:
the input side of C2305 and pin 3 of U2302 (for
7800 radios) or
the input side of C2605 and pin 3 of U2602 (for
UHF1/UHF2 radios)
the input side of C2705 and pin 3 of U2702 (for
VHF radios)
Compute the 15dB step attenuator loss.
Note: The 15 dB step attenuator will be enabled.
Loss
<17dB?
No
Yes
Yes
Testing a
7/800
radio?
Testing a
700
No
Yes
3
4
No
Check digital logic to the 15 dB
Step Attenuator and replace:
U2302 (for 7800 radios) or
U2602 (for UHF1/UHF2 radios)
U2702 (for VHF radios).
if needed.
Remove SH2.
Measure the LO
power going into
the mixer, U507, at
the output side of
R525.
Is the LO power
around -3dBm?
Yes
Note: RF Test frequency used:
UHF1: 424.975MHz
UHF2: 485.075MHz
VHF: 154.275MHz
700: 769.0625MHz
800: 860.0625MHz
Measured with a High Frequency Probe for relative comparisons and troubleshooting
only. Actual S21 gain or loss may differ if the test point is not 50 ohms.
Check FGU
and replace
U507 if
needed.
Yes
Testing a
UHF1/UHF2/
VHF
No
Yes
2
Содержание Astro APX 3000
Страница 1: ...APXTM TWO WAY RADIOS APX 3000 DETAILED SERVICE MANUAL ...
Страница 2: ......
Страница 4: ...Notes ...
Страница 6: ...vi Document History Notes ...
Страница 10: ...x Table of Contents Notes ...
Страница 12: ...xii List of Tables Notes ...
Страница 18: ...xviii List of Figures Notes ...
Страница 22: ...xxii CommercialWarranty Notes ...
Страница 46: ...3 20 Theory of Operation Main Board Notes ...
Страница 84: ...3 58 Theory of Operation Bluetooth Notes ...
Страница 147: ...Troubleshooting Waveforms Clocks 6 3 6 2 2 4 MHz Clock Trace 1 Trace recorded at R6113 Figure 6 2 4 MHz Clock Waveform ...
Страница 154: ...6 10 Troubleshooting Waveforms Audio SSI 6 3 4 BCLK Trace 1 Trace recorded at R6107 Figure 6 9 Audio SSI BCLK Waveform ...
Страница 156: ...6 12 Troubleshooting Waveforms RX SSI 6 4 2 DA Trace 1 Trace recorded at R2805 Figure 6 11 RX SSI DA Waveform ...
Страница 157: ...Troubleshooting Waveforms RX SSI 6 13 6 4 3 FSYNC Trace 1 Trace recorded at R2804 Figure 6 12 RX SSI FSync Waveform ...
Страница 159: ...Troubleshooting Waveforms TX SSI 6 15 6 5 2 DA Trace 1 Trace recorded at R2817 Figure 6 14 TX SSI DA Waveform ...
Страница 160: ...6 16 Troubleshooting Waveforms TX SSI 6 5 3 FSYNC Trace 1 Trace recorded at R2807 Figure 6 15 TX SSI FSync Waveform ...
Страница 161: ...Troubleshooting Waveforms SPI 6 17 6 6 SPI 6 6 1 CLK Trace 1 Trace recorded at R2803 Figure 6 16 SPI CLK Waveform ...
Страница 162: ...6 18 Troubleshooting Waveforms SPI 6 6 2 CS Trace 1 Trace recorded at R6602 Figure 6 17 CS Waveform ...
Страница 164: ...6 20 Troubleshooting Waveforms I2C BUS 6 7 2 SCL 5V Trace 1 Trace recorded at R2204 Figure 6 19 I2C Bus SCA 5V Waveform ...
Страница 165: ...Troubleshooting Waveforms I2C BUS 6 21 6 7 3 SDA Trace 1 Trace recorded at R6209 Figure 6 20 I2C Bus SDA Waveform ...
Страница 169: ...Troubleshooting Waveforms USB 6 25 6 10 USB 6 10 1 D Trace 1 Trace recorded at TP F_GCAI_USB Figure 6 24 USB D Waveform ...
Страница 170: ...6 26 Troubleshooting Waveforms USB 6 10 2 D Trace 1 Trace recorded at TP F_GCAI_USB Figure 6 25 USB D Waveform ...
Страница 172: ...6 28 Troubleshooting Waveforms SDRAM 6 11 2 CLKX Trace 1 Trace recorded at TP6308 Figure 6 27 SDRAM CLKX Waveform ...
Страница 208: ...6 64 Troubleshooting Waveforms LF CW on Spectrum Analyzer Notes ...
Страница 222: ...7 14 Troubleshooting Tables List of Board and IC Signals Notes ...
Страница 282: ...8 60 Schematics Boards Overlays and Parts Lists Main Board Block UHF1 84012513001_A Notes ...
Страница 338: ...8 116 Schematics Boards Overlays and Parts Lists Main Board Block 700 800 MHz 84012501002 Notes ...
Страница 390: ...8 168 Schematics Boards Overlays and Parts Lists Main Board Block VHF 84012512001_A Notes ...
Страница 456: ...9 8 Debugging Fixture Powering up Covert Board Notes ...
Страница 468: ...Glossary 10 Glossary Notes ...
Страница 472: ...Index 4 Index Notes ...
Страница 473: ......