From: John Woodgate
Subject: Re: Wideband gain measurement
Date: Wed, 9 Oct 2002 14:33:46 +0100
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Wed, 9 Oct 2002 14:31:27 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Ban wrote
(in ) about 'Wideband gain
measurement', on Wed, 9 Oct 2002:
>you can greatly increase the accuracy with a precision adjustable attenuator
>and your scope as a display.
> generator>input amp>Channel1
> output amp>attenuator>Channel2
>now adjust the generator that the amp is in a linear region without
>overload, high enough out of the noise and hits a horizontal line(90%) on
Before you go on, disconnect the amplifier and attenuator from the scope
and connect the generator, at the output level setting you have just
found, to BOTH channel 1 and Channel 2. Adjust the channel gain controls
until the two traces exactly co-incide. You have thus eliminated any
error due to channel gain difference from your measurement.
Then re-connect the amplifier and attenuator to channel 2 and go on to:
>set the attenuator course to-30dB and adjust the fine scale until both
>traces are of equal height. Write down the value, it corresponds to the gain
>of your amp.
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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