N.Ganesan - VU3GEK-KJ6LRR
The LRR401 is a high performance general coverage double conversion super- hetrodyne HF communication Receiver, utilizing high selective filters and with excellent dynamic range double balanced mixers. This approach results in excellent SSB/CW and AM reception performance. The VFO is stable microcontroller controlled DDS oscillator. Optional low-noise analog variable audio filter circuit used here for improved audio easily compares the reception with that of a receiver equipped with DSP filter. The LRR-401 combines the satisfaction of the kit building experience with the performance features expected in a modern HF receiver. This circuit design follows a standard well-proven approach based on various kits available on WWW modifications have been done.
Features & specification
q 0 to 30MHz Continues coverage.
q SSB/CW & AM.
q Sensitivity Approx. 0.2 μV.
q Frequency display readout with LCD
q DDS VFO of tuning step 1, 10,100Hz, 1, 10,100 KHz, 1& 10MHz.q 45MHz first IF,455kHz second IF
q Low-noise analog variable audio filter approx. 600-4000 Hz
q Internal speaker, 2Watts dc controlled audio amplifier.
q 12VDC @ 500ma power.
J310,BF988,MC1350,SA602,MAX293,AD9851,16F628A & TDA1013.
With 45MHz Crystal filter & 455Khz Ceramic filter
UNDER TESTING SEE THIS BLOG FOR UPDATE