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1.A SSTV INTERFACE (soundcard) to minimize RF feed back

2.A soundcard LIMITER to prevent over driving the soundcard

overall view                                                               note the green isolation xformer,mic plug,min relay
                                                                                 pc board was etched with a file

another view of the above                                          mounted and in operation on hf & 6 meters

A SIMPLER INTERFACE

CIRCUIT DIAGRAM                                             PARTS

TWIST A PIECE OF BARE WIRE AROUND MIC JACK                POT & RADIO CABLE INSTALLED
AND TIGHTEN .WRAP ONE END OF THE TWISTED WIRE
AROUND THE THEADS ON THE SWITCH AND TIGHTEN
THE SWITCH.SOLDER THE OTHER END OF THE TWISTED WIRE TO THE SWITCH
TERMINAL AS SHOWN

ADD ISOLATION TRANSFORMER. SOLDER WHITE WIRE TO CENTER LUG ON POT
SOLDER YELLOW WIRE TO TERMINAL ON SWITCH AS SHOWN. SOLDER RED AND BLACK
WIRES TO GROUND

YOU MUST MAKE THE CONNECTIONS BETWEEN THE MIC JACK AND THE SWITCH DEPENDING ON THE PIN NUMBERS FOR
YOUR RADIO (SEE YOUR OWNER'S MANUAL) THEY ARE  PTT,MIC,SHIELD GROUND,AND ANY OTHER GROUNDS
ONLY ONE LEG OF THE POT IS SOLDERED TO THE SWITCH.THE BLUE WIRE SHOWN IS NOT USED

THE CABLE COMMING FROM THE SOUNDCARD IS SOLDERED TO THE INPUT LUG OF THE POT (1K)
THE PLUG THAT GOES TO THE RADIO SHOULD MATCH THE PINS ON THE MIC JACK
I DIDN'T SHOW ANY CONNECTIONS BETWEEN THE MIC JACK AND THE SWITCH BECAUSE THE
PIN NUMBERS FOR MY RADIO MAY DIFFER FROM  YOURS
THE MOST IMPORTANT THING HERE IS FOR NO RF TO  GET INTO YOUR SSTV SIGNAL OR YOUR
MICROPHONE WHILE TRANSMITTING.THE ABOVE METHODE IS VERY EFFECTIVE IN PREVENTING
THIS
set the pot for 3/4 turn clock wise
 
 
 

                                           WA0TSL Clarence Fowler