I uploaded revision WA5BDu 1r8 of PHSNA and 4.2 of the PLX-DAQ spreadsheet.

On PLX-DAQ. I like to use the spreadsheet when plotting.  I was doing a crystal and realized that in that mode I don't get the adjustment for crystal filter loss, which in my case is the crystal fixture plus 20 dB attenuation in front of it.  I'd like my peak reading to be normalized to 0 dBm.  So I identified a cell in PLX-DAQ (O3) which will contain a flag (100) if you want the factor used.  Then I revised the PHSNA software to read that cell's contents and act accordingly.

The rest of revision 1r8 is to allow going between AD9850 and AD9851 modes relatively easily.  I added a mode flag which is stored in EEPROM and a menu option to toggle it.  On start-up, the current mode is shown.  In the AD9851 mode, the reference clock adjustment is made and the control byte is changed from 0x00 to 0x01.  If your Adruino has only been used for the PHSNA, it will come up in the AD9850 mode until you tell it otherwise.

The frequency compensation polynomial has only one set of coefficients, and the adjusted (calibrated) clock frequency is only stored once.  So if you switch modes, you'll have to re-calibrate or accept defaults for those items.

I don't have an AD9851 module with the proper pin-out lying about, so I haven't tested the software with one.  I did test the AD9850 mode to make sure I didn't screw it up.  Sure enough, I had the logic backwards in a couple places but it's fixed now.

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I've been reading crystal parameters and comparing with earlier readings using my homebrew K8IQY tester, and in some cases re-doing the earlier readings.  I'm fairly pleased thus far and interested in hearing what others are finding.  My calculated Rs does seem to be a hair (5%) low but I need to study that some more.  If it's consistent, I'll add in a fudge factor for myself, but would need some input from others before making it universal.

Happy measuring,

Nick, WA5BDU

