[Elecraft] Settings for CM500 on K3?

[David Christ]

Good posting using quantitative reasoning not just qualitative 
anecdotes.  Provides a way for others to tailor it to their own 
particular situation.  It also cites references.  This I think is a 
model post.

David K0LUM

>
>The Wikipedia entry on "Voice Frequency" states:  "The voiced speech 
>of a typical adult male will have a fundamental frequency from 85 to 
>180 Hz, and that of a typical adult female from 165 to 255 Hz[1][2]. 
>Thus, the fundamental frequency of most speech falls below the 
>bottom of the 'voice frequency' band" (that is, the 300 Hz to 3400 
>Hz band used in telephony). "However, enough of the harmonic series 
>will be present for the missing fundamental to create the impression 
>of hearing the fundamental tone."
>
>So how does this apply to the K3 TXEQ settings?
>
>The K3 transmit equalizer has eight bands. Per the K3 manual, "The 
>center frequencies of the 8 audio EQ bands are 50, 100, 200, 400, 
>800, 1600, 2400, and 3200 Hz."  Clearly, the lowest band is 
>irrelevant for human speech and can be knocked down to -16 dB 
>without losing any speech.  The second band, centered at 100 Hz, 
>will partially cover the low end of the human male voice range, 
>especially for males, but as stated above, you can knock out the 
>primary frequency and still transmit intelligible speech because of 
>the harmonics of the primary frequency. It might sound a little 
>"tinny", but it will be fully intelligible. A female user of the K3 
>might want to knock the third equalizer band all the way down to -16 
>dB as well as the first two. These would be typical settings for SSB 
>contesting where you want to maximize the modulated signal in the 
>frequency band where it will have the most effect. 
>
>If you're a fan of "broadcast quality" AM rag-chewing, you'd 
>definitely want to use different settings, probably "flat" except 
>for the lowest band for males and the lowest two bands for females.
>
>But, as others have said, the human ear is the best way to discern 
>proper TXEQ settings. You can do it yourself with a good 
>noise-sealing headphone set and the rig in TEST XMIT mode, or over 
>the air to someone who knows your voice well.
>
>Lew K6LMP
>
>