[Elecraft] Sidetone DB Measured

n4lq n4lq at insightbb.com
Tue Apr 22 18:03:14 EDT 2008


Just to eliminate some of the subjective opinions, I have measured the DB 
level with my sound level meter at a distance of 2 feet from my speaker.
Note that for CW I always use the MFJ-281 ClearTone speaker. This speaker 
has a rather sharp resonance at 650hz and is the best cw speaker I've found 
over the past 44 years. I keep the speaker directly on the desktop with a 
solid background behind it. This position provides the cleanest and loudest 
tone.
I tuned in WWV and adjusted the AF gain on the receiver for a comfortable 
level, 75 DB. I then pushed the mon button and adjusted the sidetone for 
exactly 75 DB. The sidetone level indication shows 18.
Finally, I increased the sidetone level to maximum and read an ear splitting 
91 DB on the level meter.
I've always used QSK, even back in the tube days so I'm used to the band 
noise and wouldn't want to be without it however I believe it tends to make 
us want to increase the sidetone level a bit. The internal speaker on 
virtually any rig is horrible for CW so I never use them. Those speakers are 
there just so they can claim to have one. CW tones are directional. Aiming 
the sound straight up not a good way to copy CW.
Using my Kenwood HS5 headphones, the sidetone seems about right when set at 
30 which is where I usually have it set for the speaker too. The HS5 cans 
have an 8 ohm impedance and are quiet efficient at 650 hz. Wide band, hi-fi 
cans might require more sidetone drive to mask the unnecessary frequencies.
73
Steve Ellington
N4LQ at insightbb.com 


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