I have got a thermometer with a remore temperature sensor that sends radio signals to update the base unit's display. The base unit also has its own temperature sensor to let it display the indoors temperature as well as the sensor's temperature.
The sender unit's antenna is a coil of wire which is about 1/4-inch diameter and a couple of inches long. See these pics:
2_sender_B4_thermo_(extra_panel)
TWO QUESTIONS: What is the best orientation for each of these units so their antennas are postioned optimally? For simplicity I am assuming no obstructions.