Roger Beep.

Use.
A roger beep is a device that is designed to transmit a short sound when you stop transmitting. The purpose of this is to let other people know that you have finished, and they can now reply.

Although these circuits are often included with FM CBs, they are really designed for use with SSB or AM. The reason for this is that FM radios produce quite a large amount of background noise when there is no signal and, even when a squelch is used, end of transmission is easily recognised by the white noise or "crunch" sound from the receiver.
AM and SSB sets are much quieter on receive - so you may not notice when the person at the other end lets go of their microphone. Add to this the fact that SSB sends no carrier, and it is difficult to tell when the other person has let go and is ready to receive - so the beep can be very useful for SSB equipment.

Circuit diagram.

Components:

R1 = 4k7 R2 = 10K R3 = 5k6 R4 = 47k R5 = 5k6 R6 = 470k R7 = 1M R8 = 2k2

C1 = 10 microFarad C2 = 470nF C3 = 470nF C4 = 4.7 microFarad C = 10nF R = 15K D1 = 1N4001 RV1 = 47k

TR1 = 2SA1015 or BC558
TR2 = 2SC1815 or BC183
TR3 = 2SC1815 or BC183

Component values.
Most of the passive components should be as stated. The oscillator resistors are inter-dependent and should not be changed without the correct calculations being made. Although R1 and R2 set the delay, they also set the base current through TR1 - so changing these without correct calculations could cause damage to the transistor.
The transistors are not so critical, and there are many types which could do the same jobs. The important properties are the polarity and the current ratings.
If correct setting of RV1 is difficult or more at one end then R6 and R7 may be changed.

Supply voltage.
The circuit should work with a supply between about 8 and 14 volts. So, although the main CB radio supply could be used, an internal regulated supply could be used to supply the beep.

Connecting.
To use the circuit above, the transmit connection should be disconnected between the radio and the microphone. This will leave you with two connections... the one from the radio connects to the "Radio TX" pin on the beep, and the one to the microphone connects to the "Mic TX" pin on the beep. This puts the beep circuit in series between the microphone and the radio transmit switching - allowing the beep to decide when the radio should be transmitting.
That is the only wire that needs to be disconnected in the radio - the other beep wires simply connect to the relevant points inside the radio.
It should be noted that some radios may give a squealing noise if the mic audio circuit is connected to anything while the radio is receiving. To cure this, a relay should be used to do the switching and disconnect the beep audio out while the radio is receiving.