基準発振器とオシロスコープで VCO チューニング。
なるほど!と思いました。チューナーもいつか欲しいけど、こっちだと用意するものも少なくすぐやれそうです。(5才児の餌食になって消えた440Hz発振器付きメトロノームを探すだけ)
— 引用開始
From: Ian Fritz
Date: May 28, 2006 10:49 PM
Subject: [sdiy] VCO tracking w/o counter
To: synth-diy ML
>On 2006-05-26 20:47 -0500, Paul Schreiber wrote:
>
> > You *cannot* tune a 1V/Oct input (VCO, etc) with a scope. You
> > need a frequency counter.
I’ve done it without a counter, as follows:
1. Mix a 440Hz pulse (from a xtal-oscillator timebase) with the VCO signal
and feed it to a scope.
2. By looking for stable beating patterns, set the VCO to various
octaves: 110Hz, 220Hz, 440Hz, 880Hz, etc.
3. Measure the control voltage required to get the VCO to each of these
frequencies.
4. Adjust tracking controls as usual to get 1 V/Oct.
:-)
Ian