[Elecraft] K3 sidetone level

[Bob McGraw]

I trust you have the same firmware in both radios.

Having only one K3S but I do use two identical (hopefully) speakers, I 
find the physical position of my head and ears related to the position 
of the two speakers can produce a null in the sound, especially with a 
tone.   While RX voice differences in this regard is not noticed the 
same way, a tone can be very distinct in reflections and cancellations.  
In RF we call it standing waves.  In audio, it is the same thing, just 
different dimensions, speed and frequency.

Now you say there is a difference in level settings.  By chance have you 
actually measured the audio power output of the sidetone and are the 
sidetone from the two the exact same frequency?   Are you using the same 
speakers or headphones on each radio.

As Jim, K9YC says "and I don't know the answer."   I consider him and 
Joe W4TV to be resident authorities on audio and K3 radios.

73

Bob, K4TAX



On 11/13/2024 8:03 PM, elecraft-request at mailman.qth.net wrote:
> Message: 12
> Date: Fri, 8 Nov 2024 23:39:56 -0800
> From: Jim Brown<jim at audiosystemsgroup.com>
> To:elecraft at mailman.qth.net
> Subject: Re: [Elecraft] K3 sidetone level
> Message-ID:
> 	<42c75ce2-c327-40ca-a00b-79476daf4991 at audiosystemsgroup.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> On 11/8/2024 8:36 PM, Chris wrote:
>> For some unknown reason, the sidetone level in my K3 doesn't sound right to
>> me. As some of you already know, I have two K3. The CW sidetone on one at
>> 60 generates the same volume as the other at 25.
> I've been running K3s since 2007, and I don't know the answer. It MIGHT
> be related to the speakers or phones you're listening on, or it could be
> that you're hearing a difference between the AF and RF gain settings and
> whether the preamp is on or off, and on rigs with the newer preamp
> that's in the XVTR module. If on SSB, could be difference in mics. Mic
> gain settings could be different.
>
> BUT -- the numeric values you see change with most controls are
> meaningless. The numeric value of compression, of mic gain, line gain,
> of VOX, Anti-VOX, the many ways in which AGC can be varied, are all
> examples of numeric values that are meaningless.
>
> Numeric values that DO directly reflect what we're adjusting are TXEQ,
> RXEQ (dB boost or cut), POWER (in watts) that are telling the radio to
> transmit (to the extent that it's properly calibrated), anything with
> frequency, voltage, current, the relative dB voltmeter tied to received
> signal level. The S-meter IS calibrated to voltage at the antenna terminal.
>
> I've many times described how to set up TXEQ and COMP for best sounding
> audio for communications and "talk power." I'll repeat it. First, set up
> TXEQ: turn the first three bands (50, 100, and 200 Hz) all the way down.
> Turn the fourth band (400 Hz) down by 6 dB. set the top two bands for
> 3-6 dB boost. Turn COMP all the way down. Next, set mic gain per the
> manual. Now, start turning COMP up until the on-screen meter shows about
> 10 dB of gain reduction on voice peaks as you transmit.
>
> We've accomplished two important things here. First, we've killed all of
> the voice frequencies below about 400 Hz, which do NOTHING useful for
> speech intelligibility, but burn about 3dB of transmitter power. Second,
> the COMP (compression) function turns down the gain on voice peaks,
> making the quieter parts of our speech 10dB louder. 3dB is double the
> transmitter power, 10 dB is 10X the transmitter power. So we have made
> turned our 100W radio into the equivalent of a 2kW radio! or our 5W
> radio into a 100W radio.
>
> There's one other step in this. Get another experienced ham with good
> radio ears to listen to you with the filters in his radio set fairly
> wide (like the normal 2.7 kHz bandwidth that is pretty much the standard
> of ham SSB transmission). The settings I've given above are the starting
> point for most good mics (and I don't mean expensive) for ham rigs, but
> some sound a bit different from others. And not all voices are the same.
> Some voices have lots more lows, and with these, we may need to turn 400
> Hz down more than 6dB. Remember -- we're going for talk power, whether
> we're DXing, contesting, or ragchewing with QSB.
>
> What I'm saying about speech intelligibility was learned in the earliest
> days of telephony by engineers at AT&T Bell Labs, which until about
> 1980, when the company was broken up because it was a monopoly, was the
> most important engineering organization on the planet for the prior 100
> years! The transistor was one of their later creations! They discovered,
> published, and patented most of what we know about electronics, audio,
> radio, transmission lines, and how we understand speech. They invented
> and patented the best of the two systems for stereo in 1936.
>
> 73, Jim K9YC