[ARC5] Input impedance - BC-453-B - un-un

[AKLDGUY .]

Correct me if I'm wrong, but when multiple receivers are fitted,
aren't all the antenna terminals connected together with short
wires? So effectively all receiver inputs are in parallel?

73 de Neil ZL1ANM


On Fri, Feb 6, 2015 at 7:43 AM, Kenneth G. Gordon <kgordon2006 at frontier.com>
wrote:

> On 4 Feb 2015 at 20:57, Dennis Monticelli wrote:
>
> >
> > Guys,
> >
> > Maybe we're over-thinking this input matching "problem."
>
> Well, I haven't viewed it as a "problem": I am simply very curious whether
> matching the input impedance could make any difference, either good or
> bad.
>
> > If the input parallel tuned tank's parallel resistance at resonance is
> in the
> > neighborhood of 50K ohm (as Ian reports), then let's ask ourselves what
> a 50 ohm
> > antenna looks like after passing through the series 8.5pF input coupling
> cap.
> > The series circuit of 50 ohms and 8.5pF need only be transformed into its
> > parallel equivalent circuit to answer that question.  Doing the
> mathematical
> > conversion at 400KHz results in 44K ohm in parallel with 8.5pF.  The
> > capacitance will get absorbed by the antenna trimmer leaving 44K of
> antenna
> > source resistance.
> >
> > I just don't see a need to be fiddling with input matching networks.
> And let's
> > give the ARC-5 designers the credit they deserve.
>
> Well, as I have repeatedly stated here, as far as I am concerned, the ARC
> engineers were pure geniuses. They appear to have thought of everything.
>
> Ken W7EKB
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>