Equipment to get started

Typically what you will need is whats called "Stumbling Rig", which is comprising of the following:

Laptop
A portable computer, either laptop/notebook or PDA which should be able to house a PCMCIA wireless card. Ideally it should be able to run on battery power alone for some decent amount of time. If stumbling during the daylight hours it would be beneficial to have a screen that is visible outdoors.

Software
The common "stumbling software" used is Netstumbler for laptops with Windows operating systems or the PDA version Ministumbler for PDA devices. Netstumbler cycles through all possible wireless channels, probing for networks, and reports the SSID of any access point that responds to the probe. If supported by the chipset it will also report signal level, noise level and records the data for a graphical history display. Netstumbler also supports GPS devices for recording at what location it last received a signal for each network - not so useful for a site survey but good for other types of surveys such as wardriving. For more software information visit Software to get Started.

Wireless Card
The ideal wireless card for stumbling would be a PCMCIA card with external antenna connectors. The classic example of this is the Senao 2511CD+ EXT2. Other possible wireless cards are USB wireless adapters with external antenna connectors (useful for PDAs) or a miniPCI card inside the laptop with a special "pigtail" (see below) bringing the internal antenna connection to the outside. Some compact flash wireless cards may also have antenna connectors.
The card should also be supported by Netstumbler or Ministumbler. Various cards are supported to a different degree in Netstumbler, most will allow basic detecting of networks but may not report signal level. The Senao mentioned earlier uses the classic Prism chipset which is supported 100% by Netstumbler. This list is a compatability list for cards that have been reported to work with Netstumbler.

Pigtail
A pigtail, also known as a flylead, is a small piece of flexible coaxial cable. This will connect from the wireless card to the antenna or possibly to a piece of coaxial extension cable between the pigtail and the antenna. Typically you will need a N-type connector of the correct gender (see Common Wifi Connectors) to connect to the antenna or coax extension lead on one end of the pigtail and the appropriate connector to connect to your wireless card at the other end of the pigtail, typically an MMCX, MC or RP-SMA connector. Internal miniPCI cards use the u.FL type connector. All combinations are either readily available or can be made to suit. See your card manual for details.

Coax (1-5m)
Coax on a stumbling rig is a great idea as it allows the laptop to sit on the ground or in the lap of an observer. This allows you to have another hand free for stablising yourself on the roof/ladder/mast. It also makes it less likely to damage the fragile pigtail as there is more slack cable to work with. Essentially it is just a coaxial extension lead with an N-type connector on both ends, one end plugs into the antenna, the other plugs into the pigtail. Make sure the genders are all correct however it is always wise to have a few gender changing connectors around just in case. Good cable to use in this situation is LMR200.

Polarised Small antenna
A cantenna, yagi or a 15dBi parabolic grid antenna are best for doing a site survey (aka stumbling) as they can be held relatively easily in one hand and don't have much wind drag. If you can pick up signals at a reasonable level with a small antenna like, it is certain that moving to a larger antenna in a permanent setup is feasible. If you can only pick up a few ESSID beacons here and there from the low gain antenna you can try again with a higher gain antenna and verify if the signal is usable with more gain.

Controlled Test
Its worth testing your equipment with a AP that you know is in range at a range of around 20 metres to first see what a good signal is like, then cover the AP in a damp towel, in a plastic bag of course, to show what a poor signal is like. If you know your stumbling rig is working you can do a site survey, it is very unlikely that you will pick up no signals from APs. If you can not detect any APs then chances are your stumbling rig is not working properly.

Safety Equipment and Buddy
Even for simple acts such as holding a ladder or calling for tools it is a good idea to have a buddy present. Stumbling can be dangerous. Air-Stream will not accept liability for injuries sustained while undertaking wireless site surveys or installs, but reccomends using best practise which includes identifying hazards and risk minimisation. This includes wearing a harness, stumbling during dry and daylight conditions, always having at least two firm footholds and a hand hold and safe use of electrical equipment.

Air-Stream Stumbling Kit
If you don't have access to stumbling equipment, there is ready made stumbling kit available to any Air-Stream Member with everything you need to do a site survey.

If you have all of these things arranged in advance you will have a much more succesful site survey, best of luck!

Software to get started

Stumbling Software
Software that you use for a site survey is often refered to as a "stumbler" because you can stumble across wireless networks that you didnt know about before. It gives you an update about what the radio in your wireless network card receives through the antenna.

SSID
The information you receive is the following and ESSID which is a piece of text used to identify the wireless network. Airstream networks have an ESSID in teh following format "Air-Stream-Suburb-Name".

Signal, Noise and -dBm
Stumbling software also allow you to see the recieved signal strength intensity "RSSI" or signal strength. Along with the signal you will also see a certain amount of background noise. Ideally you want all signal and no noise. Or at least more signal than noise, hence we have a signal to noise ratio(SNR) we want a really high SNR. Both signal and noise are typically measured in -dBm which is a negative log scale.

What is a good signal?
The weakest signal is around -100dBm and the strongest signal is around -10dBm each 3dBm closer to zero is a doubling in signal. If you have a signal of -80 dBm to -1dBm you can get a decent 11Mbps link, with a signal of -90 dBm to -100 dBm your link will have problems and packet loss.
Also a SNR of at least 5 is required.

Scanning through channels
There are 13 channels on the 802.11b range of frequencies. A wireless card reads from the radio tuned into one channel at a time so it may take some time to scan through all channels, you can also lock a piece of stumbling software into one channel to focus on a particular AP on a given channel giving you better feedback rather than hoppign through all channels at once.

Netstumbler and Ministumbler http://netstumbler.org
And an excellent Windows application, with a full GUI, compatible with most wireless cards, including Prism chipsets (Senao) and Hermes chipsets (Orinocco, Lucent, Cabletron). The graphical feedback is easy to interpret at a glance.

Screenshots

Kismet
POSIX (Linux, BSD, Unix) based software. Good for identifying networks but difficult for determining signal strength, uses a scale of 0-255 from minimum to maximum and doesnt seen to isolate the signal to noise ratio per SSID. A small kismet drone or drones can be placed on a remote access point and relay packets to a kismet server. The kismet client then connects to the kismet server and displays the data as a text display. The client and server can be on the same physical system or on seperate systems connected by a network.

Screenshots

Wavemon
POSIX based software, uses the ncurses text package to display signal strength and other information graphically.

Screenshots

dstumbler
BSD

Screen shots

7 Channel LPT Port Controller

This circuit is drawn out in such a way that it can be easily assembled on vero-board. Not all 7 relays are required eg JF only uses only two, northfeild five and Carrick Hill will only use one.

The aim of this circuit is to enable a system script to reset or power cycle an ethernet AP's when they crash, which does happen from time to time. This is very usefull where access to a site is limited.

Download High res PDF

A Site Survey: Quality and Range of AP signal at your site

The only real way to tell if you can connect to Air-Stream or not is to get to the highest point on your property and do a site survey. The equipment required to do this is explained in Equipment to get Started which you may already have. If you are a member there is a stumbling kit* available for loan, or a generous member may be willing to help you out or lend equipment.

A site survey is the process of measuring which microwave signals emitted from Air-Stream Access Servers are accessible from your a handheld antenna and laptop. Also the strength and quality are assesed. Most of the time is is done on your roof. It doesn't take very much time if done properly and will answer the question "Can I join the Air-Stream Network?" once and for all.

*Note: The stumbling kit is available to Air-Stream members. Contact for more details.

Add an image to your post

Adding an image to your posts is easy.

First create a page and write your story, then scroll down to the File Attachment Link

Attach your image file.

Once the image file is attached, you can the place the image in your story with some html like I have done for this page.

Calculating the length of an Antenna

To calculate the wavelength of an Antenna the formula for Wavelength is the Speed of Light ~299,792,458 metres per second divided by the frequency in Hertz. However, because electricity travels slower through some materials than others, there is a need to reduce the speed of light by the Velocity of Propagation also commonly known as the Velocity Factor for example a piece of copper wire has a Velocity Factor of 0.951.

Consequently the formula of a full wave antenna at 2.447Ghz (Channel 8) using copper wire is:

(299,792,458 x 0.951) / 2,4470,000,000 = 112mm

A Half Wave antenna would then be 56mm and a Quarter Wave antenna would be 28mm

Please note: This is only a guide to home made antenna building, when looking around the Internet you'll find many variations to this calculation due of a number of reasons ranging from rounding down/up or ways to match the impedance of the antenna with the feed line.

For example feed lines for Transmitters and Transceivers are 50 Ohms so too Wireless LAN equipment. However a half wave dipole is 72 Ohms and a quarter mono pole is 30 Ohms but for maximum efficiency both feed line and antenna must be the same impedance. Consequently there are many tricks employed to achieve a match and no doubt antenna design is a very complex area, but you'll be surprised of what can be done with a little experimentation, specially as the equipment used in Wireless LAN is very low-powered and therefor the risks of equipment damage and interference is minimal and so well worth having a go.

Changing ACK timeout on various OSes

Throughput can be improved over long distance links by changing the ACK/CTS timeouts and Slottime, see http://www.air-stream.org/ACK_Timeouts

RouterOS

The ACK Timeout option is found in the Winbox GUI under the "Advanced" tab for the interface settings - make sure "Advanced Mode" is clicked on. RouterOS has a feature which dynamically calculates the ACK Timeout, this is the default option and seems to work well for most installations. For manual setting of the ACK Timeout just type in the number in microseconds and click Apply.

Atheros cards using athctrl

athctrl is a small utility for Linux that changes the ACK Timeout, CTS Timeout and Slottime based on the maximum distance you specify, in meters. It's usage is:

athctrl [-h] [-i device] [-d distance]

The maximum acktimeout/ctstimeout possible on atheros based cards is currently 409 µs, working out to a maximum distance of about 53-57 km.

Examples

athctrl -d 1000

Set maximum distance of 1000m for wifi0.

athctrl -i wifi1 -d 5000

Set maximum distance of 5000m for wifi1.

OpenWrt + Madwifi

The physical layer parameters are stored in /proc/sys/dev/wifiX

To view a parameter, such as acktimeout on wifi0

OpenWrt:~# sysctl dev.wifi0.acktimeout
dev.wifi0.acktimeout = 22

Example

I want to set up my 802.11a card, wifi0, for an 8 km link.The default slottime is 9 and the default acktimeout is 22 as discovered from the above command.

I must add 1 to slottime and 2 to acktimeout for every 300 meters over the initial 300. This means I need to add an extra (8000 - 300) / 300 = 25.7 to slottime. I will round up to 26 to be safe. So my slottime will be 9 + 26 = 35, and my acktimeout and ctstimeout will both be 22 + 26 * 2 = 74.

This can be manually done as follows

OpenWrt:~# sysctl -w dev.wifi0.acktimeout=74
dev.wifi0.acktimeout = 74
OpenWrt:~# sysctl -w dev.wifi0.ctstimeout=74
dev.wifi0.ctstimeout = 74
OpenWrt:~# sysctl -w dev.wifi0.slottime=35
dev.wifi0.slottime = 35

To make this permanent on bootup, one would add the following lines to /etc/sysctl.conf

dev.wifi0.ctstimeout=74
dev.wifi0.acktimeout=74
dev.wifi0.slottime=35

BSD

sysctl can be used in BSD based operating systems to access and modify the parameters, the format is similar. 

Example

For example on interface wl1:

~# sysctl -w dev.wl.1.acktimeout=74
dev.wl.1.acktimeout: 22 -> 74
~# sysctl -w dev.wl.1.ctstimeout=74
dev.wl.1.ctstimeout: 22 -> 74
~# sysctl -w dev.wl.1.slottime=35
dev.wl.1.slottime: 9 -> 35

To make it permanent on bootup, one would add the following line to /etc/sysctl.conf

dev.wl.1.acktimeout=74
dev.wl.1.ctstimeout=74
dev.wl.1.slottime=35

OpenWrt Whiterussian + Broadcom

The dctrl utility by nbd or an nvram setting in Whiterussian can be used to specify the maximum distance between stations. dctrl usage is:

dctrl [max distance in meters]

In Whiterussian RC5 or higher, the nvram setting wl0_distance can control the maximum distance, specified in meters. A small utility called sdist, attached to this page, can be used to verify that the correct registers have been changed. Remember to run /sbin/wifi to reload wifi settings after changing nvram.

Example

Checking initial values using sdist, then changing wl0_distance to 20kms, reloading wifi settings. Checking that the registers in the wifi card actually changed, then committing the nvram so the wl0_distance setting persists on reboot.

OpenWrt:~# ./sdist
shm: 0x9
reg 684: 0x207
OpenWrt:~# nvram set wl0_distance=20000
OpenWrt:~# /sbin/wifi
OpenWrt:~# ./sdist
shm: 0x8f
reg 684: 0x28d
OpenWrt:~# nvram commit

HostAP + Prism ?

Do we care?

Note about Atheros: If using 802.11g it would be a good idea to lock the station into 11g, to prevent slottime resetting if a 11b client tries to connect. This is accessed in Linux/Madwifi through iwpriv <interface> mode 11g and in BSD through ifconfig <interface> mode 11g

Circular Wave Guide Antenna for 5.8Ghz 802.11a

Inside Diamter of Tube = 35.8 (Type 40 Copper Water Pipe)

Operating Frequency = 5800MHz
Lower Cut Off Frequency = 4908Mhz
Upper Cut-Off Frequency = 6410Mhz
Total Length = 69.5mm
Feed distance from back = 22mm
Feed Probe Length = 11.5mm
Expected Gain 8dbi

Coaxial Cables

	Any 50 Ohm coax will work for attaching external antennas on wireless network equipment for 2.4Ghz and 5,8Ghz equipment. However there are a number of factors that affect performance due to rf leakage and attenuation due to materials and shielding used by manufacturers. These factors become more important the higher the frequency and lower the power level used. Both apply to wireless network equipment and so it is important to use higher quality coaxial cables or keep lengths to a minimum. This translates into a 50 Ohm coax cable with a non-foam dielectric eg Teflon, PTFE or polyethylene and double screened shielding with less than 1.5db per metre at a frequency greater than 2 GHz. But remember a loss of 3db means a 50% reduction in power...
Examples are: Semi-Rigid RG402U or RG405U suitable for hard wiring and fixed pigtails LMR195 suitable for making Pigtails max 3 Meters CFD200 or CNT200 suitable for making Pigtails max 5 Meters CNT400, CFD400 or LMR400 suitable for Antenna runs up to 10 Meters LDF4-50A (Heliax) suitable for Antenna runs up to 20 Meters
The impedance of a coaxial cable that has a round center conductor and a round outer conductor is as follows: Zo = 138 Log (D/d) Log is always to base 10, (ln is natural log). Zo is the surge impedance, generally 50 ohms, D = inside diameter of the outer conductor, d = outside diameter of the inter conductor. Any dielectric other than air requires that the constant 138 be modified by dividing it by the square root of the dielectric constant of the insulating material.

Didz Senao 2511CD PLUS EXT2

I keep repairing my pigtail and this time its on for good. As you can see I allready have quite a bit of heatshrink on it to stiffen it. on the N-male side you can see a small bulge from when i fixed it up with solder in the past

After ripping out the main connector when tring to take out one of my pigtails I was left with one connector. Normally you can use it fine and the drivers provided say that its getting a signal but netstumbler is completly blind.

I had been soldering the pigtail onto the card but would break soon after usally when really needed like stumbling on someones roof with no plan b.

It took me a few months before I had the corage to rip the other connector and decide to make that damn coax secure by runing it though the card itself filing up the rest of the card with glue

Solding the coax onto the small tracks of the card was not hard and the coax takes the solder quite well. Someone with a shakey hand cannot do something like this, were talking millimetres here!

I had to take off the clear casing that let the LED shine though and melt away some of the inside of the casing to make the coax fit though. I went a little too far and made two holes but ah well. Those holes wont be a problem when coax and glue will be there instead.

Results are that it works! after all the work I have put into the many repair jobs im still able to pickup access points with results as if it was brand new. The soldering I have done doesnt seem to have affected its performance if at all.

Good solder joins do pay off.

Did I mention I love solder :-D

Dlink DCF-660W External Antenna Modification

There is a socket on the PCB which can be used with a pigtail, but those who have used this for stumbling, have often found they don't last very long.

Nevertheless this modification does allow the attachment of a standard 2dbi or 5dbi rubber ducky antenna, which many will have floating around the shed.

	Stage 1. Remove plastic cover, notice the metal strip, this is the internal antenna.
	Stage 2. First cut the pin leaving as much length as possible. Then bend the metal strip back and forwards until the strip brakes off.
	Stage 3. A right angle reverse SMA PCB plug can be soldered directly to the remaining metal strip. Ensure the plug is centred and alinged with the cut pin.
	Stage 4. Solder the cup pin to the centre pin of the reverse SMA Plug. Ensure that not to much heat is used as the pin may move during soldering.
	Stage 5. Place the removed cover back and mark out a slot to be cut for the connector.
	Stage 6. As noticed here the cover will not fit directly back due to the hight of the reverse SMA plug.
	Stage 7. I find the best way to hold everthing in place is to fit heat shrink, the hot glue sealed heatshink offers the best results for strength. But normal heat shrink can be used.

Equipment needed to connect into the network.

There are many different ways to connect to a wireless network over distance and even more choices of equipment. The following are three typical examples of what maybe used to connect an Access Point over 5kms in the right conditions such as: Line of Sight (LOS) , Polarization and Fresnel Zone Clearance.

Image A uses a router which can be flashed with openWRT and although this requires some coding skills it allows for the implementation of many network functions such as firewalls, routing rules and subnet allocations.

Image B uses a standard Ethernet Bridge and would represent the cheapest setup for wireless users. The limitations are that only one IP is usable and therefore will require an additional server or router if you wish to deploy subnet IP ranges over your local network.

Image C represents simplest form of set-up where the wireless device (eg: CM9) is installed into a computer or server. This offers a great number of advantages as well as its clear simplicity. The disadvantages are that the computer needs to be located closer to the Antenna, or is used with expensive low-loss coax cable which may reduce link performance.

Information on Power Over Ethernet (PoE) can be found here: http://www.air-stream.org.au/poe

Folded Dipoles

The drawing here shows the essential elements of a folded dipole and consists of two parallel elements having a constant spacing S with each element having a certain diameter, d1 and d2.

The ends of the parallel elements are connected to form a continuous loop and the feedpoint is at the center of the element having the diameter d1.

Consequently, in this calculation we use the value of single-wire dipole, the feedpoint impedance will be transformed upward by the ratio R according the equation seen below.

In free space the impedance, of a resonant 1/2 wave dipole antenna with a centre feed is aproximately 72 Ohms. Hence, a folded dipole using equal diameters for both elements will have a ratio of 4 and therefore an impedance of about 288 Ohms.

Image Assist

A new feature has been added to the Air-Stream Website called Image Assist which allows members to easily upload and insert images inline into your website blogs and comments. It automatically generates an "Add image" link under the "Body" field when creating content.

By clicking the link it opens an image browser, displaying all the images you have previously uploaded via the Images Module.

Parallel Port (LPT) Remote Control

The aim of this circuit is to enable a system script to reset or power cycle an AP or router when they crash or lock, which does happen from time to time. This is very usefully where access to a site is limited.

Nevertheless the same circuit could be used for any remote control project where you need to switch on and off a device using a computer.

The following circuits are drawn out in such a way that it can be easily assembled on vero-board.

The design allows from 1 to 7 relays to be used.

The download link for two different versions are as follows:

One Relay: http://www.air-stream.org/files/1_channel_LPT_0.pdf
Seven Relays: http://www.air-stream.org/files/7_channel_LPT.pdf

Power Over Ethernet (PoE) Building

An Ethernet Wireless Device is a very practical approach, mainly because they can be located near the Antenna in a waterproof box and the Ethernet cable can be run a fair distance away up to 300 metres in some cases.

Ethernet connections require only two pairs of cable TX & RX, but in a standard Cat5e cable there are 4 pairs. This allows for the spare pair to used for injection of power over the Ethernet. Called Power Over Ethernet (PoE) it is common practice to use the Blue and Brown pairs for this purpose.

An issue may occur on long Ethernet runs, when this method is used in combination with some Wireless Devices that require a low voltage (5V) or a regulated power.

This is because there will be a voltage drop over the length of cable due to I²R losses. In these circumstances a higher voltage is injected into the cable and a voltage regulator is installed with the Wireless Device to drop the voltage down again to the desired voltage.

An example of a such a regulator can be found here: http://www.air-stream.org/LM2576

A useful list of PoE industry standards can be found here: http://www.air-stream.org.au/poe_standards

Power Over Ethernet (PoE) Standards

STANDARD	Source Voltage	1	2	3	4	5	6	7	8	REMARKS
IEEE 802.3af using data pairs	48 V DC, protected	RX, DC+	RX, DC+	TX, DC-	spare	spare	TX, DC-	spare	spare	Industry Standard for embedded PoE
IEEE 802.3af using spare pairs	48 V DC, protected	RX	RX	TX	DC+	DC+	TX	DC-	DC-	Industry Standard for embedded PoE
Intel, Symbol, Orinoco	Usually 12 or 24 V DC	RX	RX	TX	DC+	DC+	TX	DC-	DC-	Most Brands of PoE
Cisco (OLD old standard)	48 V DC	RX	RX	TX	DC-	DC-	TX	DC+	DC+	Older Cisco polarity is REVERSED
Cisco (NEW old standard)	48 V DC	RX	RX	TX	DC+	DC+	TX	DC-	DC-	New Cisco is IEEE compliant

Run Senao PCMCIA Wireless Card in Windows

The manual provided is pretty straight forward but both the manual and drivers provided were written before Windows XP Service Pack 2 so here is how to get the drivers working.

Service Pack 1

Do as the drivers say and disable windows thing by un checking it in the properties of the wireless card.

Service Pack 2

Run Computer Management (Windows key + R, type in compmgmt.msc and click OK)

Select 'Services and Applications'
Below that click 'Services'
On the right hand side look for 'Wireless Zero Configuration'
Double click it

Select the startup type as 'Disabled'
Click OK.

This can be done before or after the drivers are installed it should not matter. If Wireless Zero Configuration is running the drivers provided will always say 'data error, check WEP settings' in the tool tip when hovering over the taskbar when you associate to any access point.

Nothing else should be needed, the drivers and NetStumbler should work normally.

Simple 3 Amp Step Down Switchmode Regulator

Although this example is 5V, there are also 3.3V, 12V, 15V, and adjustable output versions (see attached datasheet).

Except for the Adjustable output version the same layout can be used for each.

Note: Pin 5 (which is grounded below) can also be used to switch the external loads on/off via a logic input e.g. 0v or 5V, for example an LPT port.

You must be logged-on to access the datasheet.

UltraWAP power over ethernet mods

More power over ethernet mods. This one for an UltraWAP.

Sweeping the sky

Polarisation

Antennas on APs generally cover a broad spread of the horizon whereas client antennas are usually directional, focusing on a particular region in order to get more signal and less noise. Another strategy employed by antennas to reduce noise is polarisation. This removes the microwaves oscillating in any other direction apart from the polarisation of the antenna. For large range antennas there are two or three types: Omni Linear Colinear which are vertically polarised and Waveguides which are horizontally polarised. There are also sector panel antennas which can be either.
When you are doing a signal survey it is important to know the polarisation of the AP you are surveying. For a general survey, you will need to try both polarisations.

Horizontally Polarised

AP: Waveguides
Survey antenna: grid wires mostly going left to right

Vertically Polarised

AP: Omni (linear colinear omni)
Survey Antenna: Grid wires mostly going up and down

Know your antenna

If you can, go to a location with a known AP in visual contact and try seeing what you can do with your antenna to get the optimal signal. This will let you know if you antenna has any quirks and also allow you to know how your stumbling software works.

Scanning for APs

When sweeping the sky, take a good 5-10 minutes to sweep slowly around the horizon. You need to wait for the AP to send out a beacon and you need to wait for your wireless card to go through the 13 channels. Too
hasty is wastely. Take note of the general directions where APs are found and then focus in on these directions once you have found which are the most promising APs.
Once you have done one polarisation, repeat with the other polaristion. On horizontal polarisation you will pick up the wave guides and on the vertical you will pick up omnis.

Fine tuning the signal

This is only really essential when installing equipment, but while the gear is out you may as well try this as well. Find the direction with the strongest signal, move in small increments until the signal falls off. Then sweep back in even smaller increments, zig zagging across the signal until there is no more improvement. Try raising and lowering on the horizon as well.

Save you results

Once you have finished your site survey, remember to always save your results. They are of interest to other people who are in the same area and to AP owners who like to know how far their signal is spreading.
This may inspire people to put up gear at your site to be a relay point.

Stumbling Kit

The Air-Stream Stumbling kit is available to Air-Stream members to use for site surveys. The kit is maintained by Shawn and is available for loan to members at his discretion.

The kit includes everything needed to do a basic site survey:

• Handheld PDA with wireless card and stumbling software
• 14 dBi "Yagi" style antenna
• Appropriate pigtail, coax leads and connectors
• PDA docking bay, AC adapter and car charger

Bookings can be made by contacting the committee (committee at air-stream dot org.) The only thing to remember is that you will be responsible for lost or damaged equipment.

The antenna is a Yagi style antenna which can be used in vertical or horizontal polarisation and is simply pointed in the direction you wish to stumble. Other antennas can be used with the PDA, however your antenna must have either a RP-SMA male or N female connector to connect to the pigtail in this kit.

If you can stumble a site with this kit, it is fairly certain that a permanent connection could be made with a good antenna and wireless equipment.

For more information about "stumbling" or site surveys visit Equipment to get started and Software to get started