Gotcha. That makes sense. Seven Three,
Michael - K5WRN http://www.qrz.com/db/K5WRN On Wed, Nov 4, 2015 at 10:15 AM, Rick Hiller via BVARC <bvarc@bvarc.org> wrote: > The vertical scale only goes to 15 MHz…..the chart is for the performance > of the bent over whip, so lower angle radiation is attenuated. I am sure > that there is skywave produced by the bent over whip it run at 20 MHz but > *this > chart is to show NVIS* and NVIS only happens in the lower HF spectrum, as > described in the full manual. There is no NVIS from about 8 Megs up. > > > > *From:* BVARC [mailto:bvarc-boun...@bvarc.org] *On Behalf Of *Michael > Wrenn via BVARC > *Sent:* Wednesday, November 04, 2015 10:08 AM > *To:* BRAZOS VALLEY AMATEUR RADIO CLUB <bvarc@bvarc.org> > *Cc:* Michael Wrenn <michael.k5...@gmail.com> > *Subject:* Re: [BVARC] Re-SEND Correction -- NVIS -- Near Vertical > Incidence Skywave and the BVARC Rag Chew Net > > > > Rick, > > I don't understand the chart. Is it the shaded area that encompasses each > of the propagation types? If so, why doesn't the skyway extend to at least > 28 Mhz? > > > Seven Three, > > Michael - K5WRN > > http://www.qrz.com/db/K5WRN > > > > On Wed, Nov 4, 2015 at 10:03 AM, Rick Hiller via BVARC <bvarc@bvarc.org> > wrote: > > *Resent for graphics correlation correction. Thanks, Michael…….Rick* > > > > > > Recently, thanks to Jeff, AA(zero)ST, I received an installation/user > manual for the Stealth Telecom Mobile Antenna System NVIS Whip Accessory. > (PDF attached) It is an add-on 14 foot whip that is pulled down at the tip > end to make it more horizontal. > > [image: cid:image002.jpg@01D116E4.47229BA0] > > > > There are some user notes on the page that I thought interesting for > antenna aficionados. One chart, shown below, shows the effects of using > the NVIS whip, but more to the point and BVARC oriented, the chart shows > the propagation that we experience on the BVARC Wednesday Night 75 Meter > Rag Chew Net…..what we affectionately refer to as “the Donut Hole”. The > *Donut > Hole* (circle in red on the chart) is *the (varying) area were line of > sight and ground wave (if any) stop and then NVIS takes over a few miles > more away.* The dotted line is 3910 KHz. > > > > > > If you would like to read more about the NVIS and the Rag Chew Net…find it > here… > > *BVARC Tech Articles* page. > > http://www.bvarc.org/index.php?page=tech > > > > and read the article by Larry, K5LJ: > > “*Shortened Dipole Study for Conditions On BVARC’s Rag Chew Net”* > > > > Thanks to Jeff for the inspiration. > > > > Enjoy….Rick – W5RH > > > > > > > _______________________________________________ > BVARC mailing list > BVARC@bvarc.org > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > > > _______________________________________________ > BVARC mailing list > BVARC@bvarc.org > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > >
_______________________________________________ BVARC mailing list BVARC@bvarc.org http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org