[Elecraft] RE: Does anyone miss passband tuning, audio notch on K2?

[Ron D'Eau Claire]

You DO have that capability with the K2, Eddy! "Passband Tuning" is just
shifting the receive passband around without changing the transmit
frequency. 

On the K2, you just put it in SPLIT and crank the Tuning knob to center
your passband where you want it. 

A lot of the "gadgets" in modern transceivers were conceived because
they ARE "transceivers" with only one tuning knob. An awful lot of the
"features" are simply a re-naming or slightly different implementations
of the things we had on our separate transmitters and receivers 40 years
ago. 

For SSB, you can emulate "passband tuning" by setting up the for
available filters for each sideband with different BFO frequencies,
thereby moving the passband around. You then have four selectable
"passband" settings at the push of a button. Of course, SPLIT (or RIT)
works FB on SSB too. 

Sometimes I would LIKE a notch filter, but it's strictly a "nicety".

The right place for a "notch" filter is at the input of the i-f strip,
where the existing i-f filters are located. But it gets very complicated
to add such a filter at that point. I think that's why i-f "notch"
filters all but disappeared in the 1960s with the advent of monolithic
"passband" filters for the i-f. The newer filters won't provide a
"notch" but they do provide superior stop-band and skirt performance. 

Audio notch filters work well, but they require turning off the AGC to
operate properly. Otherwise, the strong signal you notch out will still
drive down the AGC, making the signal you want to hear even weaker. So
you can turn the AGC off, but I suspect that a lot of ops would sorely
miss it. AGC and S-meters are gadgets that most ops have gotten used to
over the years. 

I haven't been highly motivated to mess with a notch filter because it
isn't often that I really need it. The K2 filters are VERY good! 


Ron AC7AC
K2 # 1289

I don't yet own a K2, but I wonder if those that do secretly wish they
had 
passband tuning or an audio notch filter of their K2? I was just on 40
CW 
working a pileup and the first thing I reach for is the passband tuning
knob 
after going to the tight CW filtering to control of QRM!

Your thoughts about this would be greatly appreciated!

73...ed