Wszechprzepustowy transformator szeregowy APTS (all-pass transformer / series)

The presented all-pass transformer / series APTS circuit divides the entire frequency band into sub-bands, in the case of APTS2 lower and upper, which are transformed separately by each of the component transformers. APTS seems to be competitive with a single wideband transformer, assuming no negative feedback from behind the transformers. Apart from the band limitations, this circuit is in fact an first order all-pass filter APF1, which is an undesirable feature here. APTS can therefore be used as an RF transformer, for example an antenna transformer, or even an output transformer of a low-frequency tube amplifier (feedback from the tube anode).