[Premium-Rx] WTB: Sinadder 3 or ??

[Dr M J DiGirolamo]

Hi Gang,

  Have been performing sensitivity tests (12 dB SINAD) on some receivers
using a IFR-1500 Service Monitor.  I see there's a device, the Sinadder 3
made by "Helper Instruments" which would make things a little easier for me.

   Anyone have one that's not being used anymore?  Whatcha got?  Maybe
another model or mfr?

73,

Mike, W4XN
W4XN at arrl dot net