I came up with the idea of using my Amateur Radio Station like popular cordless telephones. My radio is KENWOOD 144/440Mhz FM dual bander TH-79 with DTMF-keyboard.But public telephone system in my eria is puls dail. For this i am using interface equipment appear in schematic with PIC16c84. The telephone company requires that phone lines be isolated from voltages from the user's system. This normally requires transformers and relays.But here i use optoisolators(with an isolation rating of 2.5kV)instend (QST Oktober 1981)
The program sorse for pic16c84 in ASM format. To download click here. 4K
You can e-mail me clicking here
