Is the DSP blanker input level also subject to AGC? Duncan, W5DC
Wayne Burdick wrote: > Wes, > > The DSP NB causes some artifacts at its higher settings. This is an > unavoidable side effect of signal processing. > > The DSP NB is applied after the crystal filter, so the bandwidth is > already constrained, removing some of the inherent characteristics of > noise pulses, including their rise/fall time and shape. Thus it is > harder for the DSP to distinguish between signal and noise. On the > other hand, this is the only way to remove narrow-band noise (e.g., > noise that appears every 10-15 kHz on a particular band, rather than > blanketing the entire band). The DSP NB also has the advantage of not > being "pumped" by distant signals outside the crystal filter. > > The IF NB has the opposite situation to contend with. Noise pulse > shape and rise/fall time are preserved, so they can be effectively > gated. But if you set the threshold too low, the IF NB's noise gate > can be modulated by very strong adjacent signals. > > By including both, we give the operator the ability to optimize the > ratio between IF and DSP blanking, which can be extremely effected as > attested to by many customers. > > 73, > Wayne > N6KR > > Wes Stewart wrote: > > >> Thanks Merv, >> >> So it isn't my imagination as some have inferred. >> > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
