He notes (pun intended) that he is able to discern an improvement in copying weak signals on CW by listening to a station with both of his receiver's VFOs tuned to receive the station but with a separation between them of 65-80 Hz.
The article goes into the details of how and why this is theoretically possible, touching on musical theory of the chordal scale, mathematics of accoustics/hearing and the biology of the human ear. If the math is correct, listening to a CW signal in this way should improve its perceived loudness by 6dB and that of the background noise by 3dB, resulting in a net 3dB improvement in the signal's SNR.
Many modern rigs provide the capability of listening to both VFO's simultaneously. Unfortunately, this will, on most rigs, prevent operating split since the second VFO is being used as an additional receive VFO. Flex owners can open another pan display and use it as their transmit VFO.
I am a recent subscriber to CQ Magazine's online version and am quite happy with it. I always enjoyed perusing the magazine and sometimes buying an issue when it was available at Barnes & Noble but I didn't subscribe due to the numerous negative reviews regarding timely (non)delivery of the physical magazine to subscribers.
With the 630/2200-meter bands now available for use by US hams, and a quarterly column on those bands by John KB5NJD, I thought it was time to take a chance and subscribe to the digital version. My emailed notification of each new issue's availability is received no later than the second day of the month.
Articles like the one mentioned above are the reason I'll most likely re-subscribe.