Subject: Re: [AMPS] Bias for SB-220
Date sent: Fri, 4 Jun 1999 03:23:17 -0700
From: Rich Measures <measures@vc.net>
To: "Dick Green" <dick.green@valley.net>,
<amps@contesting.com>
>
>
>
> >? How many peak volts on your 'scope? With "normal" ALC indication, my
> >TS-440S overshoots to about 120v-p. into 50-ohms. .
> >
> >I didn't measure it on my scope because I thought I needed a fast
> >peak-reading or storage scope.
>
> ? A triggered scope with a vert.-deflection delay line will see the
> leading edge.
>
Nonsense.
The time interval of the pulse is well under 1 mS. The scope would
have to be triggered from the source well ahead of the envelope
rise, in order for the trace to move off the starting point and catch
the leading edge.
If the decay time of the phosphorus is fast, the pulse will be gone
before your eye ever recognizes the pulse. That's why fluorescent
lamps, with 120 pulses of light per second, look like a steady
picture. If it was only one pulse of under 1 mS, you'd never know
the bulb lit.
You'll never see most overshoot on a non-storage display. Anyone
that understands use of test equipment would know that.
73, Tom W8JI
w8ji@contesting.com
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