Just a tickler/reminder, the broadness of the BC-348( ) can be greatly improved. Using either a BC-453 or the equivalent LF ARC-5 receiver, either of the bc band receivers, or these new Arduino minuature HF receivers seen on Ebay (for $50) will work very well.  BC band 274N or ARC-5  properly connected via pick- up loops, the 915 kHz IF can be introduced into the above receivers. That said, the BC-348 xtal filter, when properly aligned, works quite well. 

Jeep K3HVG