On Sat, 26 Mar 2016 02:17:21 -0400, rickman wrote:
Both of these pages were interesting, but hard to read. I don't get why
some pages use a light grey text. I suppose some don't have a problem
reading that, but I do, a *lot*. The other page intentionally added a
shadow to the text, not just the headings or links, making that page
even harder for me to read. I really don't get that either.
If you're using Firefox, click on the "reader view" icon.
https://support.mozilla.org/en-US/kb/firefox-reader-view-clutter-free-web-pages
There are similar features and plug-ins for other browsers.
I see all too much of the "gray text" problem that inspired such
things as "reader view". I agree, it sucks. It's the result of some
of the really bad style sheets that are found in many CMS (content
management system) web page creations. It's main benefit is that it
emphasizes the advertising. It also holds your attention longer so
that you stay on the web page longer. I can bore you with details on
how this works in advertising if you're interested.
I found a few more pages on Yagi-Uda antennas and some derivatives. One
describes how to build a Quagi antenna where the driven element and the
reflector are loops. Seems that works pretty well getting similar
numbers to Yagi type antennas with more directors.
Yep. A quagi is a square loop element. The big advantage of quagi
and loop yagi antennas is that they squeeze a few more dB of gain
(about 2-3dB) with the same boom length as a conventional yagi. That's
not a trivial amount when you consider that in order to get 3dB more
gain out of a yagi, the boom has to be twice as long.
What I really need in an antenna, is something I can add to the ubiquiti
nanostation m900 loco I am using for Internet access. The internal
antenna is only 7.5 dBi. I see a Yagi which is 13 dBi but it seems to
be out of date. The current model is very fancy and is over $200. The
other one is only $33.
I'm involved with a bunch of 900 MHz ham radio repeaters and had a
fair amount of experience with 900 MHz. I don't like yagi antennas
for 900 or 2.4GHz. I prefer patch or panel antennas. However, if you
must buy a yagi, I suggest something by Antennex or something resold
by Laird. By the time you get to 13 or 14dBi gain, the bandwidth of a
yagi becomes sufficiently narrow that you'll loose gain at the band
edges. Since your radio needs to hop from 902-928Mhz, you'll need an
antenna that's fairly flat across the entire range. Just keep your
eye on the VSWR vs Freq graphs to avoid this problem.
http://www.lairdtech.com/product-categories/antennas/yagis
http://www.l-com.com/wireless-antenna-900-mhz-yagi-antennas
Gotta run...
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558