Electret Microphone for Yaesu Ft-950

I retrofitted an old IP Telephony headset/electret mic for use with My Kenwood TS-850. With the upcoming CQ WW SSb contest I needed to now use it with the Yaesu FT-950 which required a simple wiring change . Microphone impedences are the same so i thought no other change would be necessary or so I thought. Using headphones and setting the "moni" loud enough to hear I tried speaking using the antenna switched to a dummy load . Both with and without processor, audio was distorted and scratchy- sounded like RF almost getting in.
I had fashioned this headset adapter box based on simple diagrams from " Tomi Engdahl's" website and needed to change resistance and capacitor values to have it sounding quite good with My Kenwood radio. So now I did the same with the Yaesu interface finally arriving at a better,but not great sounding audio.
Next step was to actually talk to someone and another Ham in the area helped with this. Rf did seem to be distorting the audio, using different antennas and processor on or off. Turning down mic gain did help but still was not good. Eventually gave up for the night!
Today I tried adding a ground to the case ,which strangly enough caused some hum-- must be a ground loop somewhere! Next tried multiple ferrite beads- this did the trick nicely! Audio good enough for the non-discerning ear! OK- good enough for Me! If you look at the picture,beads are between adapter and radio. Now I'm ready for this weekend's contest. High winds forcast for tomorrow-hope their wrong! Don't want any downed antennas.
73---Tim

Update- 9/27/2011--  The Electret mike worked OK but I eventually upgraded to a Heil proset plus which works great!!