I have a nanoVNA-F that I am very pleased with.
I have done the internal calibration.
I use nanosaver software on Win10, and am also very pleased with it. Do I
recalibrate using the nanosaver software for every different band filter I
am testing and save that calibration using the nanosaver software?
1. To measure the insertion loss of a bandpass or highpass filter that is
designed for 70cm, do I recalibrate using nanosaver to the design range of
the filter, or use the very wide range that was set to my internal
calibration of the unit.?
If I want to know how much loss the 70 cm. filter has inside it's passband
or targeted use frequency, should I recalibrate using 400 to 500 MHz sweep
range, instead of the 'base' calibration I did which used 50 KHz to 1000
MHz?
On the other hand, when I want to evaluate a 2m/70cm duplexer's
performance, I'm not so much looking at insertion loss as I am attenuation
of the 2m signal by the 70cm port (to prevent desense of the 2m receiver by
the 70cm uplink transmitter). I am seeing about 56 dB of rejection by the
duplexer's 70cm port, at 145.9 MHz (Non-used 2m port terminated in 50 Ohms.
I am also seeing about 8 dB more rejection of the 70cm uplink on 2m using a
Triplexer (HF/2M/70cm) LP-BP-HP, as a filter instead of the duplexer
(LP/HP). Is that expected behavior?
2. The default value in the Sweep control for what appears to be resolution
is 1, I have played with various values from 1 to 10. Obviously, the
display is much smoother with larger numbers, but it this a change in
resolution (of the data measurement) or is just a display trick? Do I get
better precision using a number greater than 1?
Thanks for your help, this little unit is a ham's dream come true.
73, N0AN
Hasan
