STEP BY STEP

1

Noch’s ‘HO’ scale Cow Pasture package provides six pre-painted cows and a single small calf, along with the sound module and loudspeaker. The cows look overly pristine and would benefit from a little weathering.

2

The mooing sound is rather loud, and it becomes tiresome after a while. Adding a switch to toggle the sound on and off is recommended, while a simple volume control can also be installed into the circuit.

3

The first job was to replace the short power input cables, neatly soldering new red and black wires to the contacts. The wires need to be long enough to reach the power supply, wherever it is sited on your layout.

4

The red power input wire was interrupted by a SPST toggle switch. The wires from the sound module to the speaker were also disconnected from the PCB (NOT from the speaker itself) and longer cables soldered to the terminals.

5

The new red output wire was then connected to the end terminal of the potentiometer, while the speaker’s red cable is connected to the central terminal. The remaining terminal is linked to the base of the potentiometer.

6

The black wire from the speaker is then joined to the new, extended black cable from the PCB output and the bare wire insulated. The input cables were hooked up to a 16V AC accessory output from a small Gaugemaster controller.

7

When happy that the switch and volume control are working satisfactorily, the speaker can be mounted wherever desired. This simple mock-up was intended as a test-bed only, so the speaker was simply glued in position.

8

A knob is required for the volume control (pushing onto the potentiometer’s shaft) and an aperture is required if mounting the speaker to a fascia. For greater protection for the speaker’s cone, drill a series of smaller holes.