But a station on 1510 kHz could also potentially produce an IF of 455 kHz and so cause image interference.
3.
As a consequence, most Autodyne receivers needed quite elaborate antenna tuning networks, often involving double-tuned coils, to avoid image interference.
4.
Later superhets used tubes especially designed for oscillator / mixer use, which were able to work reliably with much higher IFs, reducing the problem of image interference and so allowing simpler and cheaper aerial tuning circuitry.