Audio quality is excellent. There is one in continous use at the home location.

One substitue I have made is to use just the North Country Radio AM88 synthesiser section and PA (terminated with a 50 ohm resistor) to feed this circuit - directly in place of the crystal. This works well but the AM88 isn't a patch on this SPAT circuit.

An alternative aerial that limits the reach, provides hi signal in close proximity and allows the signal to be directed away from a neighbour or stops "bleeding" of a signal into nearby phonelines when using a normal wire aerial is to use a MW loop tuned antenna - about 15 inches square. Feed the output into the normal receiver single turn coupling of the loop and tune for maximum signal. This works very well. Being mainly magnetic induction rather than transmission the signal drops to the power 4 not 2: perfect in countries where even part 15 power is not allowed but coverage of a medium-size property is required.