artisan 8640B - A26 A1 Power Amplifier and AGC Detector Assembly Backdating (Change D)

Model 8640B TM 9-4935-601-14-7&P
MANUAL CHANGES
CHANGE D (cont'd)
Figure 7-3. A26A1 Power Amplifier and AGC Detector Assembly Backdating (Change D).
CHANGE E
NOTE
See paragraphs 7-26 through 7-35 for recommended instrument modifications.
Page 5-2, paragraph 5-21.
Delete section a. A8A1R4 Selection.
Add the following:
a. A8A1 R1 Selection. A8AIR1 is always 620 ohms in parallel with a resistor selected as follows:
1. Set COUNTER MODE to EXT 0-10 MHz.
2. Connect RF OUTPUT (-10 dBm at 8 MHz) to COUNTER INPUT.
3. Connect a 10-ohm linear pot across A8AlR1 (two test points beside U5).
4. Counter should hold a stable count. Decrease OUTPUT LEVEL vernier until counter just goes into random
counting.
5. Adjust pot for a stable count.
6. Repeat steps 4 and 5 until the minimum input for stable counting is reached.
7-14
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com