Z729 GEC POLKADOT SCREEN MILITARY EF86 FROM 1960
Well here's a treat, on offer is a GEC Z729, the famous POLKA DOT CHROME MESH anode EF86 variant. These devices are sought not just because they look beautiful but because they also have a wonderful sound showing low microphonics and a low noise floor - some say their slightly lower gain is a problem but believe me, the the rewards for outstrip the downside by an order of magnitude.
This device as you can see shows the full twin blue Osram decal, and is marked with the classic white GEC-Osram cartouche carrying the code Z729 and the date code QD which equates to April 1960. The pins are straight and clean, the valve tests at nominal for both anode current, Ia and mutual conductance gm using our AVO Mk 4 valve tester.
A simply super example of a rare high performance thermionic device.