[HBR] HBR-11 Template??

[Ian Wilson]

If it's in its original state, the ARC-5 BFO coil is better than tapped: it
has two windings!
There are also (if I recall correctly) two fixed and one trimmer capacitor
in the can. So
you can build a Hartley if you wish.

If have built 85kHz BFO oscillators using an RFC (5mH?) in a Clapp-type
configuration.
That worked out very well in terms of tuning range with a 100pF variable
capacitor.

Most solutions will work fine at this frequency, stability is unlikely to be
an issue.

73, ian K3IMW