[Elecraft] Keying Bandwith Modification: Done

[Ron D'Eau Claire]

The files ARE impressive, but raise some questions.

Knowing how the windows sound player can add artifacts and not knowing =
what
the test setup was, I took a look at the spectral distribution of the =
two
files and was surprised:

At 700 Hz from the carrier:

Before the mod energy is down -40 dB
After the mod it's only down -25 dB

At 1.5 kHz from the carrier:

Before the mod, down -50 dB
After the mod, down - 40 dB

At 2 kHz from the carrier:

Before the mod, down -60 dB
After the mod, down -42 dB.

No doubt the mod offers an IMPROVEMENT in clicks! So I'm suspicious of =
the
sounds of clicks in these files. I got interested because my as-yet
unmodified K2 sounds more like  the "after" than the "before" file.=20

I check clicks by listening on the high-frequency side of zero beat, so =
my
receiver isn't attenuating the signal anyway, rather than tuning to the
"other side" of zero beat. So I did the above checks at the point where =
the
signal appears to be right at zero beat.=20

I AM NOT suggesting that the click mod doesn't work. I AM suggesting =
that
this shows how hard it is to devise meaningful tests at times.=20

I have no doubt that the extensive testing done by Wayne and others =
confirms
that mod does make an improvement.=20

Ron AC7AC

-----Original Message-----
> I recorded 2 .wav-files , one premod and one after the mod.
>=20
> You can download them at http://home.vr-web.de/~hms/elecraft/

Very impressive demo Martin!

--
73,=20
Sverre

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