Wow, this is an example of dedication to the cause. I think many of us wimped out when confronted with the complex circuitry of the test device prescribed by DeMaw, but Rob G7WKE actually built the thing, and did a great job on it. I’m tempted to suggest that Rob might want to set up a small business leasing this rig out to less dedicated filter builders. Or perhaps he could have batches of crystals sent to him for DeMaw-ian analysis.
Hi Bill,
After listening to you and Pete discussing crystal filter design during SolderSmoke 197, I thought you might be interested in my latest project.
This is the Crystal Tester from January 1990 QST that is reprinted in W1FB’s Design Notebook, which I believe is the circuit you and Pete were referring to.
It all appears to function as it should, so the next step is to sit down quietly with a pile of crystals and hopefully start along the road to a working filter!
73s
Rob G7WKE.
