The TSI Tube Shield Interface is
used to pick up the 455KHz IF signal from vintage tube receivers. The
455KHz IF signal can then be connected to the PD-2 SSB Adapter
or the DRM-1 DRM Down Converter.
It is simply installed on the last IF amplifier tube. The tubes must be
the miniature type. The circuit is a high impedance emitter follower
which is capacitively coupled to the tube, to pick up the signal.