[Lowfer] LW-MAX final amp components...

Sun, 3 Nov 2002 02:49:10 -0600

I don't have a probe yet so I have not powered up anything. I'll have to
order one this week. I need to align the new amp with it. I'll just do
captures until I can get a probe.
"IP" is steeling the show tonight, but my loop is pointing at him anyhow.
Mike>WE0H
http://www.we0h.us/lf.html

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of Bill Ashlock
Sent: Sunday, November 03, 2002 2:04 AM
To: lowfer
Subject: Re: [Lowfer] LW-MAX final amp components...

Mike R,

>My LW-MAX has a BD-135 and a BD-137 in the final circuit.
> There is a lowpass filter on the output that uses two 100uh
>chokes in what looks like a T type filter.

This is a change in my thinking on the output stage! There are the normal
output NPN/PNP transistors. But then the troublesome un-tuned filter shows
up which I have proven (at least on my bench and also in P-spice
simulations), just doesn't work! This because the high-Q loop load and lack
of any loading at the resonant freq of the filter (IE: it takes off and
rings like crazy). Have you seen this effect on your new scope?

Thanks for looking into this!

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