Dorji DRA808M

From rev0wiki
Jump to: navigation, search

The Dorji DRA808M is a 70cm band (400-470MHz) FM (analog) radio transceiver module with a 1W maximum output power. The radio measures 84mm x 48mm x 25mm (3.3" x 1.9" x 1"). It can be purchased from Tindie for $17.00 USD, incl. shipping. The module datasheet can be found here.

Comments

Testing

All tests done at 445.925MHz

Power:

  • High = xW
  • Low = xW

Carrier Frequency Deviation:

  • xHz (Narrow, Approx.)

Deviation:

  • xkHz (Narrow, Approx.)
  • xkHz (Wide, Approx.)
  • xHz (PL Deviation, Wide, Approx.)

Receiver Sensitivity:

  • xuV (Approx.)

Current (At 3.7V):

  • RX Idle = xmA
  • RX Active (Squelch Open) = xmA
  • TX Low Power = xmA
  • TX High Power = xA

Weight:

  • DRA808M with no shield can = 2.2g
  • DRA808M with shield can = 3.4g

Component List

Component Part Marking/Additional Text Manufacturer Function
RDA1845 UB141150 RDA - RDA1845 Single chip transceiver, integrating synthesizer, IF selectivity and base-band signal processing. 10mW Output power.
TMS370C002A(?) 0C002 B0C7 Unknown 8-Bit microcontroller
2SC3356 R25 NEC NPN Transistor
Unknown W D Unknown Transistor (Power Amplifier)
SGM2019-3.0YN5 YJ30 SG Micro 3.0V LDO
SJK-6U-14.74569-10-80-A-15 SJK 14.7456 Q-Crystal XTAL for Microcontroller
28.00 28.00P D150 Unknown XTAL for RDA1845

I have acquired the datasheet for the main radio IC, RD1845, and interestingly, the comment posted on the forum with the datasheet download was the following: "Radio chip, the transceiver has a lot of indicators can not meet the national standard! Careful use!" The datasheet can be found here: http://rev0proto.com/files/RDA1845_datasheet_v1.1e.pdf Additionally, the registers and programming info can be found here (for more adventurous hackers): http://rev0proto.com/files/RDA1845_registers_v2.3.pdf

Additional Photos