UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Help needed with

frsimen · 17th Feb 2023, 6:33 pm

Hello Mark,

As PJL has suggested above, you really need to repeat all the IC25 measurements with the replacement fitted. Pins 6,11,14 and 2 should all show a changing signal as there isn't anything to stop them counting in the absence of the PE pulse from TP16. If that pulse is actually present now it's possible that pins 14 and 2 won't count but they will be at 0V rather than 12V.

Paula

17th Feb 2023, 6:33 pm	#107
frsimen Heptode Join Date: Jan 2011 Location: Croydon, London, UK. Posts: 772	Re: Help needed with - Racal Dana 9081 Hello Mark, As PJL has suggested above, you really need to repeat all the IC25 measurements with the replacement fitted. Pins 6,11,14 and 2 should all show a changing signal as there isn't anything to stop them counting in the absence of the PE pulse from TP16. If that pulse is actually present now it's possible that pins 14 and 2 won't count but they will be at 0V rather than 12V. Paula