[ARC5] S+N/N ratio results - wet filter

[Bill Cromwell]

Hi,

Some unmentioned details about the wet filters from "the good old days". 
I have told other hams on other lists that the "grey filter" on the air 
works the same way it does in a popular, crowded restaurant. We listen 
to one voice and one conversation while totally immersed in dozens of  
other, nearby voices. By the way...there is a limit to how much of that 
we can do and it varies day to day and even hour to hour. The extreme 
example...we're unlikely to notice a gnat belch in a hurricane. The term 
'rotten QRM' is not something new.

It's especially easy to sort out the one voice in the crowd when it's 
our sweetheart doing the talking (grin). So the grey filter uses all of 
the "data" available to do it's job. Today most of the transmitters are 
pretty much sterile and so is the CW being sent by microprocessors. In 
the good old days a lot (most? (all?)) of the transmitters had what can 
be called "character". Add to the transmitters' character the different 
'voices' of the fists keying them. One that stands out in my mind was 
WB8MTD in the 80's on QMN. One dit and we knew it was him. There was no 
chirp and no identifiable hum on his signal but his transmitter's voice 
was dramatically *different*. It was a much easier proposition to even 
learn how to sort the signals by ear than it is to apply the already 
'trained' grey filter now. Lucky for us there aren't as many signals on 
the air these days - except contest weekends - for whatever reason.

Using narrow filters, especially if there is any trace of ringing, is 
fatiguing. I run filtering to help lift very weak signals out of the 
noise and for that they are invaluable. Most of the time during the week 
I just use the SSB or AM filters even on CW. It's more pleasant. I can 
hear what's happening on a small chunk of the band while I'm working on 
other things. I like Ken's "grey spectrum analyzer" concept.

73,

Bill  KU8H