A frequency multiplier for my 8640B. The toroid is probably 1/4” o.d., maybe an F23. I find no marks on it to identify it. It could be a ferrite with permeability of 50 for this frequency range and probably work well. The winding is 4 turns trifilar. The diodes are HP2800.
The circuit is a full wave rectifier, cathodes to the output N connector. Its not quite impedance matched, but it does work. Type N connectors.
Copyright September 13, 2006, K0CQ