Guidelines In order to access the repeater s frequency modulated carrier with a sub-audible tone of 77Hz is required on the input frequency of 29.540 MHz Particular attention must be paid to the transmitting stations' deviation settings. The optimum deviation is ± 3KHz and the absolute maximum is ± 5KHz. Above this, severe clipping of the audio occurs causing distortion. The optimum deviation for the 77Hz sub-audible tone is ± 500Hz and the absolute maximum is ± 600Hz before distortion is caused to the audio modulation. It is advisable to check your equipment deviation using a calibrated modulation meter. If you are unsure then your local radio club or repeater group should be able to provide assistance. |