The unit in my collection was purchased in August of 1989, from Antique Electronic Supply. It was featured in a sale flyer that was sent out, and I don't believe it was ever offered in regular catalogs. I suspect that their inventory of Western Radio items has long since been exhausted. The transmitter was quite simple to operate, and emitted a clean sounding CW note with 1 watt of DC input power. Here is a GIF image of the schematic for the BN-1.
All dimensions are in inches.
All coil forms are thin wall cardboard tubing. L1 and L2 are separated by about 0.06 inch. All windings appear to be 32 AWG varnish coated magnet wire.