I also just bought one, which software are you using. Occasionally when running a 0 db sweep I get the below spikes. I was also looking to do the filter mod and found the newer versions of the LTDZ has it already
I'm using my own software, it has better calibration, but limited functions
Note that 0 dB sweep leads to overload LTDZ input, because it has a little higher output than needed for mixer saturation.
So, I recommend to use it through 10 dB attenuator.
Recommended attenuators for calibration are 10 dB and 40 dB.
I attached current version of my software for LTDZ.
If possible please run it on your LTDZ device and give me screenshot with ADC output for the following cases:
- RF-IN connected to RF-OUT
- RF-IN connected to RF-OUT through attenuator 10 dB
- RF-IN loaded with 50 Ohm dummy load and RF-OUT loaded with 50 Ohm dummy load
If you don't have dummy load, just leave both connectors open for third test.
Use the following sweep parameters:
- start freq: 35000000
- stop freq: 4400000000
- points: 9999
I'm interesting if there is a difference in hardware performance for different LTDZ instance.
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Some instructions:
1) unzip and run
2) Select proper COM port at the top of window and click "Connect" button
3) Select "ADC" for Mode\Data combo box
4) Press Sweep button
for calibration:
1) press button on LTDZ to enable tracking generator
2) press "Calibrate" button
3) connect RF-IN to RF-OUT through 10 dB attenuator and press OK
4) connect RF-IN to RF-OUT through 40 dB attenuator and press OK
5) press Yes to save calibration (or no to not save, in such case calibration will remain in memory, but not be overwritten on the disk)
6) select Mode\Data = Magnitude and press Sweep to check the calibration
Notes:
- 9999 points (maximum for LTDZ) is recommended for calibration
- LTDZ has min frequency 33 MHz and max frequency 4400 MHz
- you can use your own values for attenuators in calibration procedure, just enter it's value below Calibrate button
- offset field can be used to add some offset in dB on the chart
- calibration file is saved to the file _refLogA.xml, if such file exists it will be loaded at startup. Otherwise it uses default values.
- calibration file consists of two datasets with raw ADC data in hex format with comma delimiter, taken for two attenuators.
- md5: CFF3BF1C63067D02F4EFB5553B11F39D