here
The PCB comes with 3 KVG filters and some MC1496
S42 9 MHz AM
S43 8.998200 MHZ (LSB)
S44 9.001800 MHZ (USB)
With a little fixture, I have tested the USB filter with my VNWA.
Because the impedance of the filter is about 560 ohms with 25 pF in parallel, I needed 2 LC circuits to adapt the filter to 50 ohms.
The fixture with vertical PCB screen not really necessary :
The results after tweaking the capacitors for minimum ripple (very important) :
Bandwith :
3.22 kHz @ -3 dB
3.43 kHz @ -6 dB
5.15 kHz @ -60 dB
shape factor 6/60 dB = 1.5, not bad for the price
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