ocr: ELECTRET BASE MIC Wire colours for Spare #F Insert Electret clarity only - - - PTT * - - -AUDIO Goose neck Made . - - * froM 1/2" Aluminium GROUND or Plastic piping Screened cable 3.5MM socket Place. a piece of - for plastic sleeving 0 Audio over it switch larger to SW2 direct inJection Make PP3 connections R1 Yaesu for FT290R UR1 0 D J I 2 5 SW1 3 4 Plastic project box Rear of or old Mic case Plug Box Top URI=4.7 or 10k pot. (or preset) R1 =1 1k to about 4.7k ohMs UUL o D tit Box Bottom C1 SW2 = Switches is 0.1 for to 3.5MM SW1 PTT 0.05uf only DPDT socket and -SWZ can SPDT be DMited as can Go ...