RCS controllers and transmitter/receivers are summarised here and the wiring diagram is here.
The Brian Jones Mac Five, which is shown in the diagram below, requires a 2000 microfarad capacitor to be fitted as shown to obtain a satisfactory sound. A 25 volt capacitor is shown but lower voltages can be used, depending on your battery voltage, if space is limited. The Mac Five uses one channel for loco speed and direction but has no accessory channel. The second channel can drive a separate mechanical servo and microswitch to operate the horn.
Controllers from Mtronics are connected in a very similar manner except that they do not require a capacitor, do not have outputs for the front and rear lights and also have to have the jumper links set as described on page one. They also have no accessory channel and so a separate mechanical servo and microswitch is needed to operate the horn.
Controllers from Cliff Barker are also similar except that the horn can be operated by the coupler facility and they have a rear light only which is pre-fitted. They also do not require the capacitor. The pulse rate must be set to 4KHz to work with the soundcard.
The LocoLinc KLR-102 and KLR-106 receivers have accessory terminals which can be used to operate the horn. They do not require a capacitor.
In all cases, the horn operates on a momentary basis ie. It sounds when the switch is closed and stops when the switch is opened.
