Side tone coupling: In telephones, it is the hearing of one's voice in the receiver when one speaks. Too much side tone make people speak lower and can cause feedback. Too little side tone and people may think the phone is not working or may shout.
Fig: Smooth Tone Clickless CW Sidetone Generator
Fig: Smooth Tone Clickless CW Sidetone Generator
Fig: Schematic diagram of the sidetone circuit
Figure Description:
This is a simplified schematic diagram of a receiver sidetone circuit. Because
current will not flow through a balanced circuit, the turns ratio of inductors
L1 and L2 is unbalanced by a predetermined amount and the value of resistor R is
changed so as not to match the line impedance. This way, a controlled amount of
signal can be induced into L3 to be used as receiver sidetone.
Hi
ReplyDeleteCould someone tell me, w.r.t. above circuit how to calculate the turns ratio of L1, L2 and L3 for a given amount of sidetone (say 10% of transmitter signal)?
Thanks