From: Paul
Date: Thu, 28 Mar 2002 23:08:20 +0000
Subject: Re: Ready :-)) - Re: [TSSP] short H/D and stuff
Terry,
I've been comparing the single-shot 3-24 and average-16
traces 3-26 and with the latest version of tcma there is
a clear difference emerging:
3-24 single shot TEK00000.CSV
PK FREQ kHz (Error +/-) Q FACTOR (Error +/-) LEVEL
1 229.974 (0.01%,12Hz) 466.29 (0.34%, 1.6) -0.0dB
2 578.149 (0.05%,282Hz) 184.60 (4.53%, 8.4) -26.1dB
3 904.065 (86.60%,782888Hz) 110.46 (33.98%,37.5) -40.5dB
Accounted for 99.9% of input signal
3-24 single shot TEK00001.CSV
PK FREQ kHz (Error +/-) Q FACTOR (Error +/-) LEVEL
1 229.951 (0.01%,16Hz) 283.47 (0.34%, 1.0) -0.0dB
2 577.980 (0.09%,501Hz) 169.50 (2.94%, 5.0) -22.3dB
3 903.745 (86.60%,782611Hz) 104.78 (22.07%,23.1) -36.4dB
compared with
3-26 average 16 TEK00000.CSV
PK FREQ kHz (Error +/-) Q FACTOR (Error +/-) LEVEL
1 229.956 (0.01%,21Hz) 465.70 (0.14%, 0.7) -0.0dB
2 578.100 (0.06%,375Hz) 184.74 (1.43%, 2.6) -27.1dB
3 904.140 (48.70%,440287Hz) 106.58 (16.55%,17.6) -42.8dB
Accounted for 100.0% of input signal
3-26 average 16 TEK00001.CSV
PK FREQ kHz (Error +/-) Q FACTOR (Error +/-) LEVEL
1 229.939 (0.02%,35Hz) 283.93 (0.12%, 0.4) -0.0dB
2 577.969 (0.05%,281Hz) 167.34 (0.93%, 1.6) -22.3dB
3 903.913 (0.49%,4402Hz) 102.18 (6.98%, 7.1) -37.0dB
Accounted for 100.0% of input signal
and the above are representative, we get the typical
accuracy:
single-shot average-16
f1/4 0.4% 0.2%
f3/4 4% 1%
f5/4 20% 8%
So there is now a distinct advantage to averaging over at least
16 pings.
Perhaps we should compare some 16-ping traces to some 64-ping?
As you can see, tcma is having a little trouble computing its
F error with small signals, and the levels are all wrong, but
once these are fixed, it will be ready to use.
I'm quite keen to see if two coils can be pinged together in
one trace, if you want to try that?
--
Paul Nicholson,
--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.