Several discussions with my ham colleague Gary, N3GO and wrestling in a quite area,
I believe I have ONE approach that works well and is consistent with proper results.
The main items to note: Only TWO traces are present during the cal, LESS CONFUSION!
The frequency selection I chose, start and stop, is just an example.
The use of the RESET soft touch is crucial. And I should update message #83. I believe that RESET
eliminates the BOGUS firmware process that takes you to the DONE soft key premature!!
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Calibration for 4 track nanoVNA (VNA)
Some notes: If you can have on hand another 50 ohm termination
and another female-female SMA adapter, it is helpful.
Supplied and used are the TWO- matched cables, the LOADS and one SMA adapter.
Each of the NUMBERED items below represent your PRESS (SOFT KEY TOUCH).
Turn on the VNA and note register 0 is ON.
CONNECT THE EQUAL LENGTH MALE-to-MALE COAX CABLES TO CH0 AND CH1.
1. DISPLAY
2. TRACE 0
3. SINGLE
4. TRACE 1
Now we are displaying S11 and S22 ONLY both as LOGMAG.
5. STIMULUS
6. START 100 KHZ
7. STOP 500 MHZ
8. BACK
9. CAL
10.RESET
11.CALIBRATE
Note! None of the softkeys on the right side touch screen are highlighted.
Place an OPEN on end of CH0 cable and this will be followed by a SHORT.
12.OPEN
13.SHORT
Place a 50 ohm LOAD(s) on the end of cables for CH0 and CH1.
14.LOAD
15.ISOLN
Connect the 2-cables together using the female-female SMA adapter.
16.THRU
17.DONE
Finally save to a desired register.
That's it. Check and be sure that the open, short and 50 ohm are on the proper
side of the chart. Note, the cables are CONNECTED to CH0 and CH1 and the calibration is to the end of the cables. The reference plane for insertion loss measure magnitude is in place of the adapter. However, the
phase is subject to error and that needs addressed in another message.
Also, with a thru cable connection between CH0 and CH1, the
loss measure, S21 should be nearly 0 dB.
Alan W4AMV
