Tuesday, June 23, 2009
0-500 Khz converter to 4Mhz
No big science here, the venerable NE602 working as a mixer....again...
This was part of a NAVTEX receiver experiment. NAVTEX signals are around 490 and 518 Khz so I first built an PLL oscilator for those frequencies (for a DC receiver) but the PLL never worked like I wished so the idea was first to make the conversion to 4Mhz and then built a direct receiver around that frequency. Never did built the receiver but tested the converter against my TS-50 and it did received great.
The PCB schematic is not exactly the same in the paper (different input filter) but any design with the NE602 will work.