Concise instructions on making a broadband helical antenna for 2.4GHz
use, such as:
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802.11b wireless networking
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2.4GHz video links (like hobby rockets and remote control planes)
-
Possibly Bluetooth
22/03/04 - Since I posted this antenna design several years ago,
other designs have been published (see links below) which are easier to
make and can perform just as well. Looking through forums and through
feedback there has been a mixed bag of results with how well a home-made
helix performs. The matching strip and type of PVC used can strongly
affect the performance. Antenna savvy people such as amateur radio
operators have had great results as I did. If you don't have access to
antenna analysers or the patience to tweak the antenna yourself, I
wouldn't recommend making a helix.
This is a directional antenna, not an omnidirectional antenna, so it's very
good for point to point links.
Also now in these languages:
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Türkçe
-
Bahasa Indonesia
-
Nederlands and
English. This site deals with PVC dielectric properties
which can strongly affect the helical's performance. I urge you to read this page on
recalculating the spiral dimensions before you proceed to build the helix.
Not all PVC is created equal and it's been found that differing PVC's affect
the performace of the antenna. Typical PVC pipe can have up to 40% calcium carbonate by content which may well affect the antenna
performance.
If you find any other translations, please let me know! I have no
association with the respective translations, so they may not be consistent
or up to date with the master copy.
With a about $20 in parts, a soldering iron and a free evening you can build a device to scan your local 2.4GHz band from your PC!
This WEP key generator makes 64, 128 and 256 bit keys using /dev/random on
this server.
A Power Over Ethernet project for your Access Point - with bonus 5V regulation and pretty LEDs.
This will show you how to modify a D-Link DWL-520 PCI card and hook up
an N-connector to the case of your PC for a very tidy finish - no dangly
bits. This mod can apply just as easily to other brands and models of
wireless cards.
Nifty SVG web based display for your gpsd server.
Really Old Stuff
Kernel Hacking in the RTL8181
Realtek's RTL8181 runs in Minitar's and
other vendors 802.11b access points. By default it runs Linux, the source
tree of which you can get from Minitar's download section.
Minitar's 802.11b AP Hacking forum: Forum
EJTAG info for the RTL8181: RTL8181 EJTAG
NetBSD for RTL8181 (Now dormant): NetBSD
Minitar AP Hacking Wiki: Wiki
Alternative Linux Port (VERY active, go see it): Sourceforge
Atmel's old binary driver, links to two open source Linux drivers and a
device compatibility table.
Linux driver module to allow Cisco wireless PCMCIA cards (like the Airo
34x and 35x series) to work in PLX PCI9052 based PCMCIA to PCI adapters.
This project is closed as I have dispensed with the PLX
adapter. I will leave this here for others to try out though.
Thanks to wireless.org.au
for hosting and supporting this site.
Do go have a look there for lots of other wireless
and 802.11 information.
DIY 2.4GHz Spectrum Scanner
WEP Key Generator
Yet Another Power Over Ethernet
Making a Built In N Connector Pigtail for Your PC
A Simple Web Based gpsd Client