Not knowing anything about the toroid, and the impedance of your AC line, I'm not sure how anyone could give you explicit instructions.
That said, if you haven't already, check out W9YC's work.
http://www.audiosystemsgroup.com/RFI-Ham.pdfHe has a single core "brute force" AC line filter design:
A Home-Brew Filter The "brute force" line filter of Fig
30 provides effective line filtering for the lower HF
bands (10 MHz and below). The choke is wound with
a twisted pair of #12 THHN stranded wire on a #31
2.4" o.d. core, so it can be safely used in a 20A circuit.
As in the commercial filters, the capacitor forms a differential
mode filter with the imbalance in the inductance
of the choke, and should always be on the end of
the filter opposite the noise source. Since only the
"phase" (hot) and neutral conductors pass through the
choke, the equipment ground conductor (green wire)
must be carried around the filter (that is, from power
source to load). The capacitor should be about 0.47 μF,
Only Type X1, X2, Y1 and Y2 capacitors, which are
specifically tested to withstand the high voltage spikes
that can occur on power wiring should be used. Choose
this capacitor carefully – if it fails, it couldcatch on fire!