[ARC5] What the heck is a "1/2 harmonic Q-5er?

[Hubert Miller]

The E.R. issue 304 article has a selectivity graph which shows BC-342 at about 4 kHz at -3 db and about 7 kHz at -6 db.
There is no graph for BC-348, but I "guesstimate" it about double, with the BC-348 higher frequency and low-Q overcoupled last IF.
So you have approx 7 kHz at either side of the BC-348  915 kHz with hardly any audible level change. So the BC-453 dial setting
and the 2x harmonic does not have to be exactly right on.  It will  take a narrow slice of the more broad spectrum at 915 kHz. 
If this scenario as I picture it is realistic, setting the BC- 453 at 419 kHz would not be a great big dealbreaker. Even give it one or two
more kHz if  the BC-453 is not  perfectly accurately aligned.
-Hue Miller