4 ms·
What would you suggest as an alternative? Is the SA602 or SA612 any better?
by philpem 8y ago
What would you suggest as an alternative?
Is the SA602 or SA612 any better?
- VLM 8y agoDiode ring, just like the linked article. The cool part of the gilbert cell ne602 series (and similar) is its one chip with an oscillator and a mixer and the performance is barely good enough for 1980s analog cordless phones at 49 mhz with small antennas over a short range. However intermod and strong signal performance is dismal when connected to a large 80M dipole or whatever in some ham radio application. A diode mixer will require some external (IC?) oscillator of course but performance will be vastly better. The "new era" of design as seen in some SDRs seems to be a nice DDS synthesizer driving something like a Tayloe mixer (four very fast analog switches in an IC). I don't have the numbers in front of me but from memory the 3rd order intercept point (higher means less self-generated interference for strong signals) is ridiculously higher for even a cheap analog switch IC as a Tayloe mixer. Of course the power consumption of a DDS and a fast switch will be a little higher (10x? 100x?) than an analog cordless phone chip. There's always tradeoffs.
- resters 8y agomore info on the Tayloe mixer for those interested: https://wparc.us/presentations/SDR-2-19-2013/Tayloe_mixer_x3a.pdf https://wparc.us/presentations/SDR-2-19-2013/Tayloe_mixer_x3...