This is not a real concern with SSB rigs, because that crystal filter keeps our signals on the straight and narrow (!) but with DSB rigs, what is the best SIMPLE way to keep the audio between 300 and 2500 hz? Is there an alternative to the 741 op amp configured as an audio bandpass filter?
Saturday, January 12, 2013
How should we handle the need for frequency response shaping in simple DSB transmitters? If we don't roll off the lows and the highs, we risk wasting a lot of energy on RF that will be outside the passband of the SSB rigs on the other end. This is especially worrisome if we use those cheap electret mic's that seem to have response curves from DC to daylight (well, maybe not that high, but you know what I mean).
73 Bill N2CQROur book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20