More detail information on Pocket Two Way Radio Walkie Talkie: www.dealextreme.com – 1.4″ LCD display – Frequency range: VHF136~174, UHF400~470 MHz – 99 Channels – 5/6.25/12.5/25KHz – Working voltage; 3.7V – Battery: 1500mAh – Frequency Stability: -30 ~ +60 degree Celsius – Antenna impedance: 50 ohm – RF Power Output: 2W – S/N ratio: 45dB/42dB – FM range: 87~108MHz
Testing of a newly-built 160 metre AM transceiver at Chelsea on Port Phillip Bay near Melbourne. The receiver featured in a previous video. The transmitter is similar to the one presented here: www.angelfire.com It is crystal controlled on 1843 kHz. A centre-tapped 15 volt 1A power transformer is used for modulation. Efficiency is quite high – total Tx power consumption is 1A for approx 7 watts out on peaks. The IRF510 final stage does however need to be presented with an acceptable antenna impedance otherwise distortion can appear on the output, as happened here (the switched inductor in series with the antenna has since been replaced). The transmitter’s circuit is described in ‘Lo Key’ September 2011 – published by the CW Operators QRP Club.
Video Rating: 5 / 5