Thursday, February 23, 2012
This is the schematic diagram of 40M band RF preamp with 3 tuned filters. Above image is an experimenter's 40 Meter band front end for CW. This has a double-tuned filter and a low gain, lower noise RF amplifier. This is a great circuit for isolation of a product detector or mixer in a popcorn receiver.
Sunday, February 19, 2012
Right here is definitely an simple VE7GC Popcorn RF preamplifier by Dick Pattinson. The circuit utilizes a single tuned circuit at the front end and can connect straight to a mixer or product detector in a simple receiver project. Note how Dick provided adjustable RF gain control for this circuit in his Wee Willy project on this web page. In case you can not get Tak Lee green 10.7 MHz IF coils, most likely any other brand of 10.7 MHz slug tuned IF transformer would do the job.
Thursday, February 16, 2012
This is the 6M RF preamp circuit, build using MPF102 N-Channel RF Amplifier. It really is pretty much like a 6M two-stage preamp that published in QST during the mid eighties. Doug truly favored the grounded gate FET for narrow band preamps. His published work is replete with good examples of them on just about every band. I assembled that amplifier and consider acquiring about 10 dB gain, that is all that I desired for the 6M direct conversion receiver working with a diode ring detector that I was developing. The fantastic feature of the amplifier is the fact that it integrates a band pass filter and preamp in one.