The CV633 is the American 829B re-labeled. This exhibit was supplied by Hall Electric. The logo says made in UK but the valve looks to be an American import.
The 829B American pattern VHF double tetrode is the big brother of the CV788. The American approach to twin VHF transmitting beam tetrodes was to put two separate valves within the single envelope. This design requires external neutralisation capacitances to prevent parasitic oscillations. The european design of a common cathode with independent g1's, a common g2 and single sheet anodes (seeQQV03-20 and QQV06-40A) had internal neutralisation and made the 829B and 832 obsolete, as well as offering greater output power.
This valve type would not have been the valve of choice by 1950.
The wide glass tube envelope has a characteristic bulge of 54 mm diameter that was used for retaining rings.
The octagonal lozenge around the etched 829B looks typical of RCA.
One of the anodes. The ceramic insulators are present due to the high voltages used.
The base end of one section.
The top of the valve. The beam plates are bridged and form a screen over the tops of the central electrodes. The screen grids are also joined by a strap at the top.
The wide glass tube envelope is 50 mm in diameter and, excluding the B7A base pins, is 95 mm tall.
