More Lessons Learned from Listening to the Dr.

It's a GooD thing I had no specific contest plans for this weekend as once again, everything
was all over the place.  Being an off-contest weekend (between CQ W.W. Ssb & November SS Cw),
I was not hoping for much beyond being able to test equipment configurations in Concord & Alameda; which I guess technically DiD happen.

In both locations I've been tweaking the RX audio lines looking for the correct cascade order for each device in each separate (Left/Right) audio line, using as a reference advice received from Joel Hallas (W1ZR) - the QST Dr. - back in 2014.  I even wrote a Blog Entry about this.  At the Alameda location
I recently brought back a classic Radio Shaft 15-band equalizer to process split-RX audio

I've used this equalizer during CQP expeditions to process (mono) RX audio - using the equalizer's Left Channel - and all TX microphone audio in the right.  Bringing in a classic FT-1000mp transceiver (w/dual-RX audio) and making the discovery of "Stereo Cw" has changed the RX-end of the WQ6X operating world considerably.  The "goeswith" in Stereo Cw is a doubling of equipment interaction possibilities; for better or for worse.

Cascading filters which use "infinite gain" IC's at the core of their design, is prone to outbreaks
of feedback; experienced as sudden sheiks/howls when the gain of the cascaded devices surpass
some specific (but unspecified) threshold.  In extreme cases, the feedback loop is so pervasive it requires cutting the power to the Rockville mixer (Concord) or equalizer (Alameda) and starting over.

Remember: amplifier circuits don't discriminate; whatever signals go into the amplifier are
processed indiscriminately by the bias-parameters of the amplifying device(s) along that audio path.  To be clear, noise (atmospheric or electronically created) is itself just another signal; albeit an undesired one.  DSP chips can extract/alter individual bits of any signal be-4 or after amplification; however the principle is still the same: What goes in to the amplifying stage(s) comes out more, or comes out less, depending upon the characteristics of the amplifying device (Tube, Transistor or IC).

In the world of electronics (and electron flow) we don't get something for nothing; every process has one-or-more "gotcha's".  In this blog's opening picture, the arrows represent audio flows for each side of my listening experience.  Each of those individual circuits (radio-based or external device) can easily contribute its own artifact to the audio-line that device is a part of; and, in most cases, the other audio stream (Left/Right) will be impervious to this artifact; another benefit of Stereo Cw.

After weeks of Empirical-Experimentation the various cable orders to the 4-Ch (stereo) Rockville
mixer have worked out quite nicely:

1. CH-1: ICOM 7000 (mainly for shortwave listening)
2. CH-2: Elecraft K3/0 - for remote radio access of NX6T in Fallbrook.
3. CH-3: Stereo audio from the Yaesu FT-1000mp
            A) Left Side: Unprocessed raw audio
            B) Right Side: Audio run thru an enhanced MFJ 752-B Signal Enhancer
4. CH-4: Processed audio from the Yaesu FT-1000mp
            A) Left Side: Autek QF-1A ---> MFJ-784 Audio DSP units
            B) Right Side: Autek QF-1A ---> JPS NIR-12 Audio DSP units

By combining audio from CH-3 & CH-4, mixing processed and unprocessed sound is possible. 
This helps with discerning different Ssb stations in each ear.  With a dual-RX transceiver like the FT-1000mp we get not only Stereo-Cw but Stereo-Ssb, with one voice in each ear.

 

Having an altogether genuine Japanese Yaesu SP-6 speaker allows switching (monurally)
between A/B audio for the Main/Sub RX audio paths from the FT-1000mp transceiver. 
Additionally, the AF-REV button on the bottom allows swapping audio channels as well.

The Bottom-Line: all this audio-processing equipment gives me more knobs to twiddle,
and knob-twiddling is what it's all about.

What about you?  Do YOU like to knob-twiddle?

What kind of knob combinations do YOU use?