Welcome to ETC Educational Technology Connection (HK) Ltd!
This miniature pocket Keyfob transmitter is perfect for use with the Smart Q RF Electrosmog sensor.
25-second RF Electrosmog sensor - measuring radio frequency
It's the RF transmitter we used in the `How does antenna length affect signal strength?' and `How does distance from the transmitter affect signal strength?' experiments. (The worksheets for these experiments are available from the Resources tab of the RF Electrosmog sensor).
The Keyfob is housed in a tough ABS enclosure and supplied with battery ready to operate. It operates at a frequency of 433.92 MHz with a range of up to 150 metres (optimum range - in direct line of sight). It will transmit a KEELOQ code for as long as the push-button switch is depressed and has a LED to indicate transmission.
Battery: The Keyfob is supplied with a standard cigarette lighter 12V battery type GP23A or equivalent.After approximately 20 seconds of continuous transmission the Keyfob is programmed to shut down to prevent the battery being drained through accidental operation.The transmitter encoders use EMC compliant radio transmitter modules and comply with ETSI330-220 and ETSI300-683
Note: To tune specifically to the 433 MHz frequency use a 15.3 cm long antennae [19.6 x 0.78 (the velocity factor of the coaxial cable supplied with the Electrosmog sensor)].