Here's AS' version of it
Very expensive module, will never afford it.
Here's a link to its manual, the Moog one functions in a very similar way so you might get some pointers. It's PDF, so you need a free reader like adobe acrobat reader to see it.
"A frequency shifter is a highly specialised module capable of shifting the spectrum of a signal by a fixed
amount. This is very different from a pitch-shifter and other effects such as ring modulation or frequency
modulation. (See appendix 5.)
The RS240 allows you to shift the frequency linearly within a number of ranges, the widest of which
shifts the signal by approximately ±5kHz at its maximum setting. You can use manual and voltage controls
(or a combination of the two) to achieve the desired effects. Upwardly shifted and downwardly shifted
signals are available simultaneously, both as independent signals, and as a user-defined mix of the two.
This module also allows you to shift the frequency exponentially, which will produce a number of
conventional - and less conventional - pitch shifting effects."
Here's the natty sequencer I want for mine: