Monday12 Group1

[edit] Morning

Monday morning, almost all participants were on time for this session. We had a lecture on Antennas by R. Struzak accompanied by animated demonstrations which made it easy to understand the concepts.

• Animated demonstration: http://www.amanogawa.com/archive/wavesA.html
• Lecture Notes: http://wireless.ictp.trieste.it/school_2007/lectures/

[edit] Recommended software links:

• http://www.feko.co.za/apl_ant_pla.htm
• Li et al., “Microcomputer Tools for Communication Engineering”
• NEC Archives http://www.gsl.net/wb6tpu/swindex.html

After tea we continued with antenna theory. We then took on long reach WiFi links with E. Pietrosemoli .. We got pointers on how to tweak WiFi links to overcome issues like power budget, Fresnel zone clearance and ACK timeout. From a setup he showed us in class of a setup he did with Carlos we saw that they were limited to looking for a place near the road with no obstructions in between.

He also went on to advice that a must visit site for antenna building and installation is http:// www.w1GHZ.org. During installation look to having a strong illumination in the center to avoid many side lobes.

'Radio mobile' software can be used to set the field cordinated and radio settings in a pre field installatoion preparations.

[edit] Afternoon

Rob took up building antennas in the afternoon. Below are images of some of the antennas he covered......

The Types of Antenna
1/4 Wavelength Ground Antenna with approximately 2 to 4 dBi gain	Biquad: http://trevormarshall.com/biquad.htm	Collinear Omni

[edit] Can Antenna

Portions of Rob's talk were adapted from Wireless Networking in the Developing World, http://wndw.net/

After the lecture Rob gave a step by step instruction on how to make a good tin antenna. With the help of Carlos the groups took turns drilling the hole on the tin...see image below........

The Can Antenna Lab
Introduction to can antennas	The measurements that will give the best frequency band with the tine antenna	Getting all tools ready for the demo.	Using the vice to make sure the wire is straight
Put the N connector into the vice and put the solder in the connector and using a pliers stick the wire in the N connector and solder it in.	Marking the tin for drilling the hole for connector. Measure 6 am from the back of the can and draw a circle where the N Connector will fit.	Using a horizontal drill, carefully drill a hole that fits the N connector as drawn before.	Repeat the drilling if you have to just to get it right.
Group repeats Robs Demo	Group repeats Robs Demo	Group repeats Robs Demo	Group repeats Robs Demo
Group repeats Robs Demo	Group repeats Robs Demo	Group repeats Robs Demo	Carlos helps group members take turns at drilling the hole for the N Connector

Later in the afternoon came time to measure the frequency of our tin antenna's. One of Group 1 antenna was at 2.41 to work at channel one. Ideal would be 2.422 to work at channel three.

Links

• http://trevormarshall.com/biquad.htm
• http://www.turnpoint.net/wireless/has.html

--Memories Of Group One Members By Leonado And Catherine 21:35, 12 February 2007 (CET)