Picked this up at the Livingston mini rally for a pound.
Some sort of remote aerial tuner. First thoughts were the connectors are very Larkspur, but it's painted black. Some research on line suggests it is aircraft equipment. I suspect from the size it's VHF and quite low power, but the aerial connections are for open wire, not coax. Inside there is a powered rotary switch which switches some capacitors and a small coil.
Manufacturer is STC. Front panel markings:
COUPLING UNIT AE
SER NO. B15
WT 2lbs 2ozs
I have looked in the usual places like VMARS but no hits on the model no. or NSN.
Anyone have any info or a circuit?