[Hallicrafters] Which models had the 50KC I F?

[Bruce Muscolino]

The model I am familiar with is the S-78.  There were others.  

A 50 kHz IF is better than a 455 kHz IF because it gives a sharper
response without resorting to crystal filters.  IF selectivity's on the
order of 500 hZ can be had with just the LC IF circuits.

73