Re: Ramsey Amps?

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From: W. Daniel, 9V1ZV (daniel@pandora.lugs.po.my)
Date: Tue Aug 15 1995 - 22:23:11 EDT


On Fri, 18 Aug 1995 17:43:09 EDT, "Richard G. Kellner" <kellner@usa.acsys.com> wrote:
> the push-pull circuit are not contributing equally; one side is way down.

Hi,

        I built on of them things about a year back or so. Samething.
Instructions were wrong etc etc. In any case I felt that the layout was
unstable with long lines running both the input and output. Input and output
coupling was a real likelyhood as is parasitic osc. I finally redesigned the
whole circuit on a PCB about 1/3 the original size. This has worked much
better and was giving me a little over 15 watts (depending on the power
supply) with reasonable stability. Only problem is still the biasing, the
MTP3055E's got REALLY hot after a little bit of usage. I am not sure how to
fix the biasing, and tried a few things but none seemed to make a great deal
of difference. Most likely it is a design flaw somewhere. BTW, my own PCB
design had a ground-plane for the reverse side of the PCB. I can't remember
what the signal looked like on the scope now.

73 de 9V1ZV Daniel

-- 
 Daniel Wee | daniel@pandora.lugs.po.my
 9V1ZV      | daniel.wee@f516.n600.z6.fidonet.org


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