Sensibly equivalent¶ to:
The 63SPT was A C Cossor's type designation number for the EF50s that it made and, in the case of this valve, for valves made by someone else. We also have a 63SPT with the grey painted can that was made in the UK. The 1952 advert features this can style and this exhibit is probably from 1952 - near the end of the time the EF50 was being used and long after the EF80 and EF91 had taken over as the RF valve of choice for 45 MHz applications.
The valve was so important during WWII that several manufacturers were involved although the design was a breakthrough for Philips in The Netherlands.
This valve is marked made in USA and is painted grey which is different to our other Cossor 63SPT. In a 1951 advert for Cossor in the Radio Valve Data book printed that year the 63SPT featured appears to be of the form shown above. The only difference is that the valve in their picture says made in the UK.
The wide metal tube envelope is 32 mm in diameter and, excluding the B9A base pins, is 60 mm tall.
References: Data-sheet & 1043. Type 63SPT was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated February 03, 2017.