[Elecraft] Comment on 2nd filter mod

[Ron D'Eau Claire]

I'll add to John's comments to make SURE that you are picking up the
audio from the Aux Speaker jack, NOT the "phones" jack. The caps in the
phones output circuit in the K2 roll of the response quite a bit, giving
the Spectrogram display a "tilt" that really isn't in the filters. 

Of course, if you took all your measurements through the phone's jack,
you should see an improvement, but it won't be as flat as a lot of the
images you will see of the "improved" filter.

The biggest thing I noticed after installing the mod was in how the two
sidebands SOUNDED, without even looking at Spectrogram. The "2nd Xfil
Flattening" mod came about right after I got my K2 assembled and noticed
that the two sidebands sounded totally different. Just listening to the
background noise told me that one had a LOT of high emphasis that the
other sideband lacked. To me, it made listening to SSB on the upper
bands irritating. 

Then the mod appeared on the reflector here and I installed it
immediately.  I could still hear a slight difference in the sound of the
background noise when switching from USB to LSB (that was before the
more carefully matched filter crystals were available) but the audio of
a SSB signal sounded the same to my ear on either sideband. 

Ron AC7AC
K2 # 1289