[Elecraft] K3 in WPX SSB with 2.7 roofer

[George Danner]

One of the things that Bell Labs found in adding loading coils to phone 
lines (to reduce the high frequencies) was that in an audio system if you 
reduce the high frequencies then you needed to also reduce the low 
frequencies to keep the intelligibility constant. Since a phone system 
needed intelligibility above fidelity; Bell Labs just decreased the coupling 
capacitors to reduce the low end while using the line loading coils to 
reduce the high frequencies.

I tend to use lo-cut to improve "listen ability" when I cut the high end.
I use a 1.8 kHz filter for a morning SSB net that has other nets 3 kHz away 
usually on both sides. Some of the transmitters on the adjacent frequencies 
can't fit in 5 kHz much less being 3 kHz away. The 1.8 kHz filter is the 
best solution - the filter skirts along with the DSP skirts help the most I 
can expect.

I would recommend adjusting Hi-Cut for the interference and Lo-Cut for the 
best compromise on fidelity & intelligibility; if that switches in a tighter 
filter, then that might be needed.

My 2 cents!
73
George  AI4VZ

-----Original Message----- 
From: Al
For years I have heard folks state that 1.8 kHz is mandatory for SSB 
contesting... but I have never understood how one could put up with this 
narrow bandwidth for long. I need more information hitting my ears and am 
perfectly happy with letting the famous 'ear-brain' filter extract the 
maximum from that information.