One last follow-on to this thread: In order to speed up the calibration process by being able to see the measurement results in real time while adjusting the two CalByte values, I connected the SR620 scope outputs and monitored the graphical output on my oscilloscope. It turns out that the graphical output still works while adjusting the CalBytes and makes the setup simpler (for me, anyway) than using a terminal emulator on the SR620 serial port to make the adjustments.
Stan Message: 1 Date: Wed, 30 Sep 2009 16:05:46 +0200 From: J?rg K?gel <j.koeg...@gmail.com> Subject: Re: [time-nuts] Stanford Research SR620 Measurement Bias To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Message-ID: <390229150909300705v1808d748h5376cf05e7ae6...@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Make the adjustment in the correct sequence: 1. Set the Cal jumper to Cal Enable 2. Connect the reference to Ext Ref (rear) and Input A 3. Switch the counter to Ext Ref 4. Set the CalByte 50 for the best display (this is a very fine adjustement) 5. Switch the counter to Int Ref 6. Set the CalByte 4 for the best display (this adjustement is coarse, optimize!) 7. Set the Cal jumper to Cal Disable After this calibration my SR620 is with the external reference +/- 3 counts (9'999'999.9997x....10'000'000,0003) previous value -210 counts with the internal reference +/- 6 counts previous value -25 counts Best regards J?rg K?gel _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.