[ARC5] Receiver input impedance...

[Dennis Monticelli]

It is on the high Z side.  The model for a short antenna is usually given
as a series circuit consisting of a capacitor in series with a low
radiation resistance.  When that series circuit is transformed into its
equivalent parallel R & C circuit the capacitor changes value (though not
by a lot) but the resistor does change a lot.  It becomes much larger.

Dennis AE6C



On Mon, Oct 20, 2014 at 8:08 AM, J Mcvey via ARC5 <arc5 at mailman.qth.net>
wrote:

> The ARC-5 system was designed for low-Z (12 ohm?), short capacitive
> antennas. So, in this case, the low Z side would be at the receiver
> terminals?
>
>
>
>
> On Sunday, October 19, 2014 3:45 PM, Glen Zook via ARC5 <
> arc5 at mailman.qth.net> wrote:
>
>
>
> For some reason, the URL for the Parts Express baluns didn't come through!
>
> Here it is again:
>
> http://www.parts-express.com/75-to-300-ohm-matching-transformer--180-010
>
>
> Glen, K9STH
>
> Website:  http://k9sth.net
>
>
> On Sunday, October 19, 2014 2:32 PM, Glen Zook via ARC5 <
> arc5 at mailman.qth.net> wrote:
>
>
>
> I discovered, years ago, that the lowly TV balun works wonders with
> receiver front ends.  Those available today go down to at least 5 MHz and
> my experience has shown that they work down to at least 160-meters.
>
> Here is the article that I wrote 15-years ago on this subject:
>
>
> http://nebula.wsimg.com/b489aa03011b4fc90655d356fe270973?AccessKeyId=5DDC3F25F0398F58962E&disposition=0&alloworigin=1
>
>
> Suitable baluns are available from Parts Express:
>
> "75 to 300 Ohm Matching Transformer" from www.parts-express.com!
>
>
> At 65-cents in quantities of 10, I usually purchase 10 and keep them
> around for use whenever I run into a receiver that really doesn't like
> 50-ohm coaxial cable.
>
> Glen, K9STH
>
> Website:  http://k9sth.net
>
>
> On Sunday, October 19, 2014 2:16 PM, Jim Falls <radio-tuber at att.net>
> wrote:
>
>
>
> I use a Cheapo Grande TV twin lead to cable adapter on my Super Pro. Not a
> mind-blowing difference, but these old ears can hear it.
>
> Cheers!
> Jim K6FWT
> CBLA #37
>
> > On Oct 19, 2014, at 10:12, Kenneth G. Gordon <kgordon2006 at frontier.com>
> wrote:
> >
> >> On 19 Oct 2014 at 11:51, David Stinson wrote:
> >>
> >>
> >> ----- Original Message -----
> >> From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
> >>
> >>> Thus, it seems to me that an 80:1 Un-Un might improve matters
> >>> somewhat,
> >>
> >> Ken, my guess would be that the losses in a 80:1 UNUN
> >> would negate anything gained by the match.
> >
> > Hmmm....I hadn't thought of that....
> >
> > Ken W7EKB
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