|Speaker, power supply and Box of Swifts|
We are currently testing a small number of prototype Swift call players, built out of standard, low cost electronic components, including amplifier chips. The result, called "A Box of Swifts" is a simple to use, no hassle device with a power supply in (anything between 6 and 12 volts) and a single wire out to drive a small, quality speaker.
When power is switched on, A Box of Swifts starts playing for an indefinite period of time, until the power is switched off, so controlling it with a low cost timer is easy.
Swift calls are held on a memory card, so there are no moving parts to wear out. There is no messing about with amplifiers, clamps on play buttons, or mains power to speakers.
The small speaker is easy to attach to the bottom of a Swift nest-box. 20 metres of wire to the speaker does not seem to attenuate the signal.
Although it does not have the power of a ghetto-blaster, early indications are good, with Swifts showing considerable interest.
We had success with new occupants in 3 places this year, and in other places, the Swifts responded well.
In further tests, we tried driving two speakers in parallel and in series, which might be useful in situations where you need more sound, or sound in two places at once e.g. two sides of a belfry. This works well, with the parallel configuration generating more sound, and without overheating the components in the box.
You can find instructions for operating and installing the BoS here, then hit File > download