TX3H-869.5-10

      The TX3H-869.5-10 has the following features including Standard frequency: 869.50MHz band;Data rates up to 16kbps;Usable range over 3km;Fully screened;Low power requirements.
      The TX3H-869.5-10 is an 869.5MHz FM transmitter module with a power output of 450mW nominal. It is a 100% pin-compatible drop-in replacement for the Radiometrix TX1H-151.300- 10and can be used in applications where greater radiated power is desired (for example when space limitations dictate the use of small and inefficient antennas, or for applications where the extra power is permitted). The TX3H-869.5-10 module will handle raw data rates up to 10kbps.The TX3H operates on European 869.40 869.65MHz sub-band allocation for 500mW and is designed to meet EN300 200-3 (radio) and EN301 489-3 (EMC) requirements. Custom frequencies may be available to order.
      TX3H-869.5-10 is normally driven directly by logic levels but will also accept analogue drive, e.g. 2-tone signalling. In this case it is recommended that TXD (pin 7) should be DC-biased to 2.5V with the modulation ACcoupled and limited to a maximum of 5V peak-to-peak. The instantaneous modulation voltage must not swing below 0V or above 5V at any time if waveform distortion and excessive FM deviation is to be avoided use a resistive potential divider and/or level shifter to accomplish this if necessary. The varactor modulator in the transmitter introduces some 2nd harmonic distortion, which may be reduced if necessary by predistortion of the analogue waveform.The choice and positioning of transmitter and receiver antennas is of the utmost importance and is the  single most significant factor in determining system range. The following notes are intended to assist the user in choosing the most effective arrangement for a given application.
      If the connection between module and antenna does not form part of the antenna itself, it should be made using 50 microstrip line or coax or a combination of both. TX3H-869.5-10 is desirable (but not essential) to fill all unused PCB area around the module with ground plane.