Hello Oliver,
Actually, the wider the bandwidth and the higher the quality of the
audio, the easier it is to tune accurately. Precise tuning of a 2.6KHz
signal is much more difficult than with a 3.6 KHz signal - where it is
pretty easy to achieve an accuracy of about 5Hz to 10Hz if your receiver
bandwidth can match or exceed the transmit bandwidth -- whether you're
familiar with the voice of the other operator or not. All ears are not
created equal though, so YMMV.
This is not a plug for ESSB, merely an observation. Besides... I'm a CW
op :-)
73, Dale
WA8SRA
O. Johns wrote:
Folks,
I read the web pages about ESSB, after seeing on the reflector that
the K3 now supports it. It struck me that even ESSB doesn't solve one
big issue with voice transmission: PITCH. Tuning the SSB receiver
changes the overall pitch of the received voice. Unless you have met
the sending ham or at least talked to him/her on the phone (or on
AM!!), you have no real idea how high- or low-pitched the voice really
is. One can only guess, and get a sort of feel for what a reasonable
tuning is.
One way to solve this may seem a joke, but it isn't. Everyone should
buy a little 440 Hz pitch pipe, the kind used to tune musical
instruments. Then, say, the net control could blow his pitch pipe at
the start of the net and all the listeners could blow their little
pitch pipes while listening to net control. They would all then
adjust their receiver tunings until the pitches matched. Like a
shortwave orchestra tuning up. (Of course, this might violate the FCC
rule against music on ham radio, but maybe not if the pitch pipe was
near a pure sine wave. Then the signal transmitted by net control
would be just an ordinary CW signal, but at 440 Hz from the net
control's suppressed carrier.)
A refinement would be to build a pure 440 Hz tone generator into the
microphone preamps of radios. Net control pushes a button while
transmitting and it goes out over the air. The net members push
another button while receiving to produce a 440 Hz tone in their
speakers along with the received signal from net control. Then the
receiving operators adjust their receiver tuning until the pitches
coincide. For the tone challenged among us, the receiver tuning could
even be automated, much like the K3 already does for sidetone on CW.
This scheme came to me when I was adjusting the audio parameters on my
K2. I had the K2 running into a dummy load, and was listening to it
on headphones plugged into a TenTec RX320D across the room. Since the
K2 was on a dummy load, I tried whistling and was surprised and
pleased to find that the PITCH of my whistle didn't match the one I
was hearing on the phones. But I could adjust the RX320D tuning until
they did match. Guarantee of zero beat and realistic pitch in voice
reception.
Doesn't seem that this would be too hard to do. Maybe the K3 could
even do it in firmware?
73,
Oliver Johns W6ODJ
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