On that note (?), it's good to check your soundcard levels. I can
easily drive mine into distortion, getting lots of harmonics and junk.
If you run it just below where it begins to clip and distort, there
shouldn't be much harmonic output. On the other hand, if you run it
too low, you will start picking up noise and hum when you boost your
rig's audio gain.
Cutting your passband to an octave or less (say 500-1000 Hz) is one
way to clean up the signal, but it shouldn't be necessary if you're
careful about your soundcard level.
73 Martin AA6E
On 6/3/05, R. Brent Zook <brent.zook@verizon.net> wrote:
> I learned from experience that my soundblaster card would put out second
> harmonics. With a wide transmit passband, and a 1000 hz note, you might
> also be transmitting a 2000 hz note. Therefore, I try to confine my
> transmitting to the top of the passband, or to use a narrower transmit
> filter. Same reason as using "high" tones for RTTY --Brent N9HZ
>
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--
martin.ewing@gmail.com
http://blog.aa6e.net
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