[R-390] in rush current limiters

Sun, 22 Dec 2002 20:18:26 -0600

Greetings,

        The issue, as I understand it, with the three terminal voltage
regulators is that they are noisy.  They generate hash as they do their jobs
that adds to the receivers internal noise level.  I think you will agree,
any mod that detracts from the performance of the radio is not an acceptable
mod!

Talk with Chuck Ripple....he has been down this road...that is how he came
to develop the device he offers.

Cecil Acuff

www.r1051.com

[email protected]

----- Original Message -----
From: Jim Shorney <[email protected]>
To: <[email protected]>; Helmut Usbeck <[email protected]>
Sent: Sunday, December 22, 2002 7:42 PM
Subject: Re: [R-390] in rush current limiters

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>
> On Sun, 22 Dec 2002 19:47:34 -0500 (Eastern Standard Time), Helmut
> Usbeck wrote:
>
>
> >> Question, then: what is the regulating current of this curious tube?
> >
> >It's not a tube, it's basically a FET diode.  They come in differant
> >values but not as high as .3 amps which is what is needed.
>
>
> I was referring to the original ballast tube, not a solid-state
> replacement.
>
>
> >> Three-terminal regulators can be configured as constant-current
> >> devices.
> >
> >I know and what it's being used for is overkill.  Why reconfigure a
> >voltage regulator, three- terminal current regulators are also around.
>
>
> Why?  Because they're cheap and common as dirt (I've got a ton of them
> in my junque box, including a couple of odd voltages, adjustable, and
> LDO); and because their behaviour is well documented and understood,
> including the need for adequate bypassing.  One resistor of the proper
> value is all you need to make it a CC source.  How it behaves with
> half-wave rectified AC is another question, however...
>
> - --
> Jim Shorney      -->.<--Put complaints in this box
> [email protected]
> [email protected]
> Ham Radio NU0C
> Lincoln, NE, USA
> EN10PT
> http://incolor.inetnebr.com/jshorney/
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