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[jamsat-bb:11887] Tone frequency was 1783.5Hz

眞田さん、大谷さん、皆さん、

CoolEdit2000 における周波数表示方法について、本家(フランス管制局)に尋ね
てみたところ、皆様ご指摘のように、"下記 2."  の方法が正しいという回答を
受け取りました。 6月2日付の wavファイルにおけるトーン周波数の正確な数値
は、『1783.5Hz』 とのことです。

要は、FFTプログラムの解像度の方が、マウスカーソルの動きよりも優れている
ということです。この 1783.5 Hz の数値を用いて改めて衛星内部の温度を計算
すると、約 -0.8[C]  になります。

  T[度C]＝1.256*F(Hz)−2240.9＝1.256*1783.5(Hz)−2240.9＝-0.824[C]


(質問)
Date: Tue, 04 Jun 2002 01:25:06 +0900
From: Mineo Wakita <ei7m-wkt@asahi-net.or.jp>
To: f6agr, f1hdd
Subject: How to analyze using CoolEdit

Hello,

I have one question how to analyze a frequency of the wav file.

  http://www.ne.jp/asahi/hamradio/je9pel/20602ide.wav

In the above wav file, the tone frequency appears at 20 seconds
after starting.  I analyzed this tone frequency by the following
two methods

1. CoolEdit2000 - Analyze - FrequencyAnalysis - Pause - Put MouseCursor
                                                 at the top of the peak
                 --> Then, 1788Hz on 'Frequency' in the Analysis window

2. CoolEdit2000 - Pause at 20 seconds - Put a dotted vartical line on
                      a red vertical line - Analyze - FrequencyAnalysis
                 --> Then, 1783Hz on 'Cursor' in the Analysis window

Which method is correctly either 1. or 2. ? 
1788Hz or 1783Hz ?


(回答)
Date: Mon, 03 Jun 2002 21:25:01 +0200
From: ruygh@attglobal.net
To: Mineo Wakita <ei7m-wkt@asahi-net.or.jp>
Subject: Re: How to analyze using CoolEdit

Hello,
the right one is 1783.5 Hz. You are right when putting the analysis time
with the cursor onto the sample window. Measuring the frequency with the
cursor is very imprecise since with a 8192 points FFT, you would need a
display with 4096 horizontal points which doesn't exist. Thus the cursor
position on the FFT analysis display covers more than one point of
analysis hence it is erroneous.
Best 73


-------------------------------------------
Name: JE9PEL/1 脇田
Mail: ei7m-wkt@asahi-net.or.jp
URL : http://www.asahi-net.or.jp/~ei7m-wkt/
QTH : Yokohama, Japan
Date: Jun 4, 2002
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