For sale is a vintage Marconi (GEC/Osram) U50 full wave rectifier tube, made in England. The production codes are ZO and JB.
The tube is in very good condition.
The test results using a B&K 747 Dynamic Mutual Conductance tube tester are 75/81 where the minimum result for a good U50 on this tester is 24 with neither shorts nor gas.
Pick-up is available in South Yarra, Melbourne. Domestic shipping is $10 and
international shipping will be individually calculated and invoiced (to the US is $19 USD).