[AMPS] pills and rc feedback

[g8gsq@qsl.net]

sorry for the late reply - spamcop has the whole of the UK's biggest ISP blocked so I couldn't post to the reflector. I'm trying this through a webmail account.

-----Original Message-----
From: Steve Thompson <g8gsq@qsl.net>
To: amps@contesting.com <amps@contesting.com>
Date: 17 January 2002 07:38
Subject: Re: [AMPS] rc feedback and "pills"


>
>-----Original Message-----
>From: skipp isaham <nospam4me@juno.com>
>To: amps@contesting.com <amps@contesting.com>
>Date: 17 January 2002 02:52
>Subject: [AMPS] rc feedback and "pills"
>
>
>>
>>-
>>Thanks Steve,  I didn't mention it at the time,
>>one can find feedback to reduce the entire stage
>>gain at lower frequencies and across the actual
>>device(s).  Sometimes both in the same circuit.
>>-
>>One purpose is to level the stage gain, the other
>>to prevent  "or cure" problems.
>
>Indeed - you can always add a rfc in the path if gain levelling isn't
>needed. In the manufacturing side, hfe is deliberately kept low where
>possible to help prevent instability problems, but the circuit designer has
>to do their bit too. It's interesting, and often frightening to redraw a
>circuit as it looks at lf. There's often no damping at all, and what you
>draw is the circuit of an oscillator. I much prefer to try and get the bias
>and supply loading right, so the stability is there without the feedback
>components.
>>-
>>Other than your pill information below, the only
>>mention of pills as rf transistors  that I have seen
>>has been by CB'er amp hacks "because they
>>look like pills."  They weren't using "pill" because
>>they were on the manufacturing side of the device.
>
>For sure - I guess there was a common root to the usage.
>
>Steve
>
  


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