10-07-2013, 07:54 PM
Actually generally the older battery sets are simpler to repair. Most are TRF sets (tuned radio frequency). A series of RF amps usually 2 or 3 ( these are all tuned to the same frequency amplifying the signal from the antenna), a detector stage, (turns rf signal to an audio signal) and two stages of audio amplification (take a weak audio signal and makes it loud enough to drive a speaker).
There's no frequency conversion, no lo, no IF stages. Much easier to align. The Trirdyn is a little tricky as it uses 3 tubes. 1st tube is the rf amp, 2nd tube is the regenerative detector, and the 3rd tube is the audio amp. Now for the tricky part reflex. If you look at the schematic you will see audio transformer #6 that is feeding the audio signal back to the 1st tube the rf amp.What is happening is the audio signal is being amplified again by the rf amp tube. One tube working as two tubes pretty tricky!!!
More later when I dig into this set.
Terry
There's no frequency conversion, no lo, no IF stages. Much easier to align. The Trirdyn is a little tricky as it uses 3 tubes. 1st tube is the rf amp, 2nd tube is the regenerative detector, and the 3rd tube is the audio amp. Now for the tricky part reflex. If you look at the schematic you will see audio transformer #6 that is feeding the audio signal back to the 1st tube the rf amp.What is happening is the audio signal is being amplified again by the rf amp tube. One tube working as two tubes pretty tricky!!!
More later when I dig into this set.
Terry
