Valve Protection

Radio Record, Volume III, Issue 15, 25 October 1929, Page 12

Valve Protection

"Rough" Usage Beneficial AN instance of supposed rough treatment, now stated to be good practice, may come as a surprise to many. Careful valye users are accustomed to switch off their valves before removing them from the holders. It is now asserted that this practice is liable to result in damage to the filament, since it is in a comparatively brittle condition when cold. On the other hand, when the filament is glowing it is much more elastic. Consequently, if a valve is removed from its holder without switching off the filament supply, there will be little risk of damage to the filament from the slight shock which usually occurs as the valve legs are withdrawn from _ close-fitting sockets. It appears, therefore, that .the most convenient practices are also those to be recommended for long valve life. Anyone who is thoroughly accustomed to the handling of valves will do well, however, to take out the B battery positive plug before changing valves in their holders.