Gerhard Fiedler connectionbrazil.com> writes: > If you're talking USA, it's the FCC regulations. Harold has a collection > , specifically part 15 Hehe, I feel that my case is covered by FCC part 15.13, but 15.111 contradicts everything I know about radios I owned and worked on ... Example: Assume LO1 = 1mW and mixer isolation 40dB from LO1 to input and RF amp reverse gain of 40dB one has 1mW - 80dB ~= 100nW into the antenna. 2nW into the antenna requires something like 120 dB isolation from LO1 to antenna. Not likely in any commercial or consumer receiver (and actual LO1 levels are more like 10mW and higher for professional receivers). What am I missing ? Realistic figures figures for a low power FM front end are like LO1 ~= 10mW, attenuation to ant in ~= -60dB (10uW or 22mV@50Ohms at the antenna - ten times as much as I intend to radiate). I guess I'll simply cheat and measure the LO stray radiation from a CE and FCC approved radio at the antenna, and produce as much power with my thing knowing it must (?) be reasonable vs. FCC and CE ... incidentally for 10.7MHz IF1 any FM radio's LO1 stray emissions lie inside the 88-108.5 MHz FM band for at least half the channels tuned, by design. Peter P. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist