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Leon Crampin · 30th Nov 2020, 11:03 pm

I can't throw any light on the term "stacked IF".

A reasonable way of coupling a 'scope to the oscillator valve in many cases is to drop a screening can over the oscillator valve, without allowing it to contact its earthing skirt.

There is usually enough capacitive coupling to the oscillator anode to get a good trace via a 'scope probe connected to the loose can. This will work even with an internally screened valve such as the ECH81 without pulling the oscillator frequency very much.

Leon.

30th Nov 2020, 11:03 pm	#17
Leon Crampin Octode Join Date: Nov 2005 Location: Surrey, UK. Posts: 1,874	Re: A Few Radio Related Questions I can't throw any light on the term "stacked IF". A reasonable way of coupling a 'scope to the oscillator valve in many cases is to drop a screening can over the oscillator valve, without allowing it to contact its earthing skirt. There is usually enough capacitive coupling to the oscillator anode to get a good trace via a 'scope probe connected to the loose can. This will work even with an internally screened valve such as the ECH81 without pulling the oscillator frequency very much. Leon.