The microphone is plugged into a standard DIN receptacle inside the shroud, and the cable at its far end has a DIN plug that connects to the Anabat detector. The capsule behind the microphone contains a preamp with 75 ohm output resistance that is capable of driving long cable lengths. Any of the Anabat microphones can be used, including the standard microphone that otherwise is incapable of driving long cables. The capsule is potted and sealed to prevent moisture entry.
- DIN connector with a PVC
mounting washer, sealed contacts
- preamplifier attached to connector and to the cable
- PVC capsule (Spears #429-005 1/2" sch40 straight
coupler, cut to 1.5" length)
- PVC cap (Spears #448-020 2" sch40 threaded cap, center drilled/tapped PG7 )
- Heyco PG7 gland nut
- Canare type 4E6S star-quad microphone cable to the desired length
- Heyco PG11 gland nut to seal the entry to the enclosure around the Anabat
- DIN 8 connector that plugs into the Anabat.
When completed and tested, the space behind the preamplifier is sealed and potted with electronic grade epoxy.
More details of the cable wiring can be found at http://www.nevadabat.com/
This preamplifier draws less current drain than the special "hi mic" that is sometimes used for long cable runs, 0.5 milliamp vs 4.5 milliamps. It also has a lower output impedance, 75 ohms vs 1000 ohms, that translates into a better response at high frequencies on long cables.
Photos in the natural setting courtesy of Dr. William Rainey.
These systems also include the enclosure mounted on the pole,
next to the solar panel. The enclosure holds the
Anabat, z-Caim, battery, data logger, and power controller.
A
NEMA 4 enclosure (rated proof against rain and spray) holds the Anabat
and the Zcaim, along with a 1.2 amp-hour sealed lead-acid battery and
an OWL2pe data logger/ power controller/battery charger. The
controller is programmed to turn the Zcaim and Anabat ON 20 minutes
before local sunset and OFF 20 minutes after local sunrise.
Running the equipment only during the hours of darkness conserves the
battery and allows the system to operate on a smaller battery.
The data logger records the battery voltage as well as the external
temperature and humidity, and optionally weather parameters such as
wind speed and direction. Note that the microphone cable comes into the enclosure through a gland nut, as do the other cables. Power to both the Anabat and the zcaim are supplied via the controller, through the 12 volt input barrel jacks. There is also a connection from the controller to the Zcaim that implements the power control, remotely "pushing" the Power button on the Zcaim.
Temperature
and humidity data are useful to assess environmental conditions. A 5 watt solar panel can maintain the system. The Zcaim/Anabat requires between 10 and 20 milliamps while in operation. This solar panel can provide 350 milliamps in full sun, but on dark days It may only produce 5 to 10 milliamps. The OWL2pe controller can adapt and shut down the system during particularly bad weather.
A modification is also necessary on the stock Zcaim. We install a stereo phone jack on the side of the Zcaim, with connections that allow the OWL2pe data logger/controller to turn on the system and to monitor its status. In the photo, the blue wire connects to common, the red wire via a diode to the Zcaim power pushbutton, and the yellow wire via a 10kohm resistor to monitor the Zcaim power supply.
