You don't really need the 4H4 -- unless you live in the boonies and have really poor regulation on your line voltage. Just plug a 6V6 into the socket.
Grant/NQ5T > drawers(bands) were the same. After much poking and prodding > and tube testing, come to find out the 4H4 has a broken > filament wire, which means that the HF oscillator and the > mixer aren't getting any filament volts. Now I need a > replacement 4H4.
