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

Chris55000 · 29th Jun 2020, 9:27 am

Hi!

It's normal for the eye balance indicators on bridges to open fully at one end of the balance (and sometimes the "power factor" control) this is because, with the usual wiring arrangements, (see my circuit diagram and others in this thread) the wiper of the balance control is directly earthed along with the cathode of the indicator, so when you turn the wiper towards the end connected to the grid circuit of the indicator, you're short–circuiting it's input and therefore the eye will open fully!

Chris Williams

29th Jun 2020, 9:27 am	#83
Chris55000 Nonode Join Date: Aug 2007 Location: Walsall Wood, Aldridge, Walsall, UK. Posts: 2,874	Re: Hunts CRB3 Hi! It's normal for the eye balance indicators on bridges to open fully at one end of the balance (and sometimes the "power factor" control) this is because, with the usual wiring arrangements, (see my circuit diagram and others in this thread) the wiper of the balance control is directly earthed along with the cathode of the indicator, so when you turn the wiper towards the end connected to the grid circuit of the indicator, you're short–circuiting it's input and therefore the eye will open fully! Chris Williams __________________ It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed!