UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - FT-101ZD sizzling sound on tune up into dummy load.

G6Tanuki · 21st Oct 2019, 1:18 pm

As mickm3for says, the coupling-capacitor from driver-anode to PA-grid is a known weakness in these radios - you could say it's the equivalent of "that capacitor" in valve broadcast-radios!

If it goes a bit leaky it can cause all sorts of odd and inconsistent behaviour of the PA-current during tune-up. If it fully-fails you'll be needing a new set of PA bottles and possibly a new mains-transformer too.

21st Oct 2019, 1:18 pm	#4
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,998	Re: FT-101ZD sizzling sound on tune up into dummy load. As mickm3for says, the coupling-capacitor from driver-anode to PA-grid is a known weakness in these radios - you could say it's the equivalent of "that capacitor" in valve broadcast-radios! If it goes a bit leaky it can cause all sorts of odd and inconsistent behaviour of the PA-current during tune-up. If it fully-fails you'll be needing a new set of PA bottles and possibly a new mains-transformer too.