K3: listening to both rcvrs

[Mike Cox]

I think the questions regarding addition of noise from one Rx to the
other Rx are interesting but not entirely relevant  to my own use of the
dual receivers for split frequency DXing.

Here's the way I normally deal with a split frequency pileup (using a CW
pileup as an example). Remember that myself and numerous others copy
much better when the signal is coming in BOTH ears (sounds like it's in
the middle of the head) as opposed to only ONE ear. We'll say the DX has
split a couple of KHz up the band and the pileup is several KHz wide. My
main Rx is on the DX and I'm in the split mode with the SUB Rx ON (I
will transmit on the sub Rx freq). The main Rx is set very narrow
(usually 100 - 300 Hz wide). The sub Rx is set about a KHz or more wide
so I can hear a greater swath of pileup signals and listen for the
station the DX is currently working. Here's how I run the audio with the
Orion or Kenwood (using headphones):

Left Ear: Main Rx ONLY (DX station only, NO added noise from the sub Rx)
Right Ear: Main + Sub Rx (combine the two in phase) This is also my Tx
frequency.

Here is what my brain perceives: The DX is in the middle of my head and
is easy to decipher (much easier for me than if the DX was only out to
my left). The pileup and most of the noise are outside of my head,
somewhere to my right side. It becomes a simple matter to pay attention
to the right side pileup and tune for a responding signal while the DX
station is not transmitting. Even though the pileup may not quit calling
while the DX station sends, when the DX station is on, it is very easy
to ignore the noise out to the right side and concentrate on what the DX
station is sending in the "middle" of my head. Even with the weakest DX
signals, I seldom ever turn off the sub Rx. The noise is simply ignored
in my head at the appropriate times. When scanning the pileup for the
"workee" on the right side, it is not necessary to achieve a solid copy
but only to recognize that magic "599 TU" report. Then you know you are
nearly on the spot the DX station is currently monitoring. The
additional noise added into the right side from the main Rx is not
really an issue and, in fact, it only becomes harder to copy stations in
the pileup during the DX stations' transmissions. That's not really a
bad thing since the DX station achieves a "perception priority" over the
bedlam of the pileup. The DX is in BOTH ears. The noise is only in ONE
ear. If the DX is in the left ear only, it only achieves, at best,
parity with the pileup in the right. By the way, the bedlam of the
pileup is usually many dB louder than the typical band noise so the
discussions of additive noise floors are really about a miner annoyance
compared to hundreds of transmitters pounding out their calls in the
pileup. Depending on the loudness of the pileup and how well your brain
has adapted to this system, you simply adjust the sub Rx volume so that
it doesn't detract from the copy of the DX station. That way, for me,
the DX station always achieves the magic priority over the pileup in my
organic signal decoder.

I currently run the K3 with stereo speakers. I set in front of the left
speaker and place the right speaker at my far right. For me, it works
better for copying the DX than using the headphones with the DX only on
the left side. It's the simplest of audio mixers. An SSB pileup is
handled the similarly except the passband of the sub Rx is not opened up
beyond normal voice response. I surely would like to use the "cans" so I
can get rid of the computer and fan noise!

Anyway, that's the way my brain does it best.

Good DX,
Mike, AB9V
>
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