The TYS5-3000 is one of the largest silica valves made. The main picture shows the valve in its supporting box. For transportation the box was further housed in an outer wooden crate.
We do not have accurate date information. The 1962 Mullard data book does not have any silica valves and the data-sheet is about 1958. We suspect the design is much earlier.
The thin plywood box as seen from above.
The protective box seen from the side shows the fixings.
The TYS5-3000 was designed for both transmitter use and for industrial heating applications.
This exhibit is one of four TYS5-3000's rescued after the closure of the former Lucas-CAV site in Acton, London W3. The TYS5-3000 was used in induction hardening plant for diesel fuel pump camshafts and starter motor shafts. This exhibit was a spare. The valve had been re-manufactured and left in store. Essentially, with the exception of the main silica tube, the valve is new.
The top of the valve shows the Mullard name and the valve type in raised letters moulded into the silica cap.
The filament connections.
The anode and grid connections.
The TYS5-3000 is directly heated with a thoriated tungsten filament. The top of the grid cylinder is visible as is the grid spiral emerging from the left of the top ring. The outer cylinder is the nickel anode.
Looking through the envelope the distorted image of the electrodes shows the ripples in the diffiicult to make silica envelope.
For induction heating applications the operating frequency would most likely have been 450 kHz.
For full details of this valve, a PDF of the data-sheet can be found as a link from the valve name at the top of the page.
The exibit was donated complete with its original packing crate.
The silica tube envelope is 97 mm in diameter and, excluding the connecting leads is 540 mm long.