Has anyone out there ever used a 3B/240M (CV2214) valve / tube in an HF amplifier? I came across one of these, new and boxed, amongst my collection of treasured family heirlooms…it looks like a miniature 5B/254M but isn’t. The 3B/240M or CV2214 is a small grounded grid triode for use up to 200MHz. It […]
SEI Crystal Filter Data
Some years ago I acquired some superb…and originally very expensive…SEI Crystal Filters on 1.4MHz. I knew I had a USB and LSB pair, but didn’t know which was which and had no idea about the correct termination impedance. What I needed was SEI Crystal Filter Data…which no one had. There have been lots of questions […]