MSD Tach Adaptor Help

[Corey Stup]

Off the subject, but does anyone know what makes up a MSD 8910
(voltage/white
wire trigger) tach adaptor?  I can't find one locally, and since it
looks
like a 2 wire transformer(?), seems to be easily constructed.

My VW's fuel pump relay isn't sensing the RPM signal after the addition
of
the MSD.  Funny thing is, the tach works great.

Any responses can be directed to cstup at pobox.com.

Thanks in advance!