1296MHz filter

Going to TRY and make one of these for my bodging to build a DUC/DDC 23cm to SDR rig. I have a problem creating harmonics from the mixing products of the Si570 that I have used to create the 23cm TRX.

From W1GHZ design, from here, of course it uses an Altoid tin so that HAS to be good to start with :-)

The dimensions are a tad precise.

"Resonators are 21.2 mm center to center. Coupling rods are 8.8 mm
center to center from outside resonators."

Good job I have an accurate digital caliper.