Valve selection box

[djrm]

Greetings, I collected this assortment of old valves from my son recentley, he saw them in his local charity shop at $1 each or $20 for a box full. I got them out again yesterday looking for a couple of octal pentodes, everythin but it seems. There are a few interesting ones in the collection. I especially like the blue one and the photo-cells. There were many more all glass types too in the box. The big one at the front is a gas filled regulator I got from a sale last year together with the audion I showed recentley. David.

   

[boater sam]

The photocells are scrap as they have been exposed to light too long.

[djrm]

Hi Sam, I never knew they failed like that, do they need replacing from time to time in old equipment like sound film projectors? I have an old 16mm sound projector and th sound isnt too good for a number of reasons. A missing bulb and failed output valves were the main problems though. David.

[boater sam]

I have never played with sound projectors but I know that the photocells must be kept away from direct light when not in the projector. The packaging has a warning about exposing them to light.