Quote:
Originally Posted by ischmitz
Are you sure you're doing this right? You need +5V power on pin 40 relative to pin 20 (GND). Then confirm you have a strong 5V p-p 6 MHz clock signal on pin 19 and a weaker version of the same signal on pin 18.
Maybe check the good DME to confirm your scope is set up properly to detect the 6 Mhz signal.
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NOK DME (copy from above) and OK DME bench test values written thereafter
Pin 5 4.85 V 33 Hz OK: 9.2V 50Hz
Pin 18 0.8 V 33Hz OK: 2,4Vpp (0.3-2.7V) 3.3 - 3.8 MHz
Pin 19 0.9 V OK: 1.2V- 1.3 V 16.7Hz
Pin 40 4.8 V OK: 4.95 V DC
Pin 9 kept resetting. OK: 0.435V DC
Adv11 OK 7,3V 50Hz
Scope is a Hameg HM412
Sanity check, 1kHz signal from signal generator
From that I calculate 6.75 waves in 10 div × 1ms/div= 6.75waves in 10ms --> 1000ms/10ms x 6.75=675Hz....
I calculated the frequencies of the DME signals the same way. What am I missing?