Whirlpool

Hello.

Myself and 2 mates want to connect to each other using wireless 25dBi directional parabolic antennas: www.baileyladders.com.au...ecifications.pdf
I am situated roughly in the middle, while 1 friend is 6.5km away and the other is about 10km in another direction. The plan is for both of my mates to point an antenna at my house, while I mount 2 antennas, each pointing back at one of my mates. Kind of like the following ASCII diagram...

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We have various reasons for not using an omni directional antenna.

We have decided that it is best to mount a device in a weatherproof container, up on the mast near the antenna. My question is - what device? It must have an ethernet port and obviously an RF socket too (to plug in the antenna). We are going to run Cat6 cable from the device down into the house and into the computer or switch (and possibly use Power-Over-Ethernet to power the device).

Each of my mates need one device while I probably need 2 (one for each antenna). Alternatively, I could get a single device that has 2 independently-controlled antenna sockets... if such a device exists.

I am asking anyone with knowledge of such devices to please give me some advice.

Thankyou.

Ok 3 major questions:

Whats your budget?

Are your houses in line of sight? With no sever objects blocking

Are you technically minded or do you require a simple solution?

Theres really more questions that need to be explained but answer those first. Budget is very important i've don a 10Km link and its not cheap if your want it stable

thanks for the response.

Whats your budget?

We are prepared to spend up to $300 for each device. As for everything else (except the mast), it will cost us about $230 each. (antenna, pigtail, LMR400).

Are your houses in line of sight? With no sever objects blocking

We are going to mount the antenna as high as we need to, for line of sight.

Are you technically minded or do you require a simple solution?

We have some technical skills but we would like to avoid using a linux box if possible. (I was hoping a device would do the job)

bagurk writes...

We are prepared to spend up to $300 for each device. As for everything else (except the mast), it will cost us about $230 each. (antenna, pigtail, LMR400).

You'll need a bigger budget you'll be lucky if mainstream hardware will support 10km range

You'll need a commercial device for the 10km so be prepared to spend more

BTW check how high you'll have to go to reach LOS cause you dont want to go wasting your money for it not to work

You wont need a linux box so im not sure why you though that, i recon the hardest part for you guys will be figuring out your LOS and keeping to your budget

Im heading home for the day but theres been post about this before and a few cheaper routers you can use

But check out your LOS first i got to stress that one

BenMHarvey writes...

You'll need a bigger budget you'll be lucky if mainstream hardware will support 10km range

You'll need a commercial device for the 10km so be prepared to spend more

Are you sure about this or just guessing, because I have read success stories of ~10km links where relatively cheap mainstream devices are used.

As far as i know, signal quality is determined by-
1. how much gain the antenna has and
2. the power output of the wireless device

Also is affected by the length of the Aerial cable so the best suggestion is to wire the Aeriel, Access Point all into a waterproof PVC pipe to mount on your roof. Then you just need to wire some power and ethernet up to that obviously a quality job you dont want to blow your hardware up if water leaks in

We intially used Dlink 3200 as our Access Points but we kept having annoying signal issues at first we thought it was our antenna's because we made them ourselves but we swapped to mickrotik AP's my mate does alot of WiFi work between office blocks and his building sites so we had the pleasure of swapping and trying other equipment

But yeah he was the brains behind the link, but yeah like i said do the research prior to doing anything, we are lucky because between our houses is just bush

Im not %100 sure but heavy residential and business area's can affect the signal strength although this may not be correct

Also is affected by the length of the Aerial cable so the best suggestion is to wire the Aeriel, Access Point all into a waterproof PVC pipe to mount on your roof. Then you just need to wire some power and ethernet up to that

Yes, I mentioned that we will do this in my first post.

Someone has recommended that we use minitar APs.
This device with a single ethernet port seems ideal. I can only find one place in australia (SA) that sells it, but it is very cheap - $35.

Does anyone else have any comments?

Cheers

That Minitar you link to only has 14dBm for g-mode, which is 25mW.
Have you had a look at the websites for freenet-antennas and rf-shop?

I also think the minitar dont like long distances and will time out from the lag delay due to the distance but i may be wrong

That Minitar you link to only has 14dBm for g-mode, which is 25mW.
Have you had a look at the websites for freenet-antennas and rf-shop?

Hey. I had a look at the freenet-antennas site, and found the UltraWAP access point. This device appears to be highly praised and has a much higher power output than the minitar. Looks like this one is our best option at the moment. Thanks for your comment.

look up the old network system that was happening back early 2000... in Sydney (i think)
they just used rabbit ears, pair gain (not sure), and just tried to convince everyone else to join in and form a free network.
but it seems you want to send a signal to a direct source...
just chucking in random info that may help out.

hey some more info:

"It’s the law*
Note that there are legal limits on the output power of an 802.11 device and that by combining a high-gain antenna with a high-powered router you could be breaking the law. For example, Buffalo informed us that attaching a 5dBi antenna to its AirStation G54 HP unit would cause output to exceed the legal specification. If in doubt, check with the antenna supplier before purchase. "
www.pcauthority.com.au/F...e-to-wifi.aspx/2

*just there for legal buffs.... but im sure it wont matter if its for private use

cmdhit writes...

It’s the law
Note that there are legal limits on the output power of an 802.11 device

2.4 GHz has a limit of 4W EIRP, thats the output from the transmitter and the gain of the antenna combined BTW

Mark can you help me then what are the legal limit on a 5Ghz connection. I actually had no idea there was a law restricting the upper power

2.4 and 5.8 are the same, 4W EIRP, unless you are in a "remote" area doing a point to point link, then you can use 200W EIRP if you meet the special conditions published by ACMA. 5.4GHZ is 1W EIRP, a bit of light reading here www.comlaw.gov.au/comlaw...D0B?OpenDocument

Thanks for the info i'll have to check this out lol i might be breaking the law

How would they regulate this?

Well lol i'll read up on that thanks for the info a well earned :D

update-

a friend pointed out this package:

host219.ipowerweb.com/~f...820b309dbd22c1db

seriously considering it!

Be wary of the effective speeds you'll pull over those distances its quite low powered which means it complies with the law but my ADSL2+ connection is prolly going to be faster than the effective speed

bagurk writes...

a friend pointed out this package:
Point-to-point bridge kit
host219.ipowerweb.com/~f...820b309dbd22c1db

Yes those are good, and they even come preconfigured however you will need two of those Bridge kits (4 radios in total) if you want to set up two point-to-point links.

Have you had a look at this integrated radio/antenna, the Deliberant 2112? - it has 250mW output power in b-mode but only 12dbi antennas so may not go the distances you need.

Link: www.rfshop.com.au/Produc...899/Default.aspx

On a sidenote...

I wonder how much EIRP 250mW with 12dBi antenna makes? Is it 24dBm("250mW") + 12dBi = 26dBm("4 Watts") ????

I know 4 Watts is the max EIRP for 2.4GHz band, but not sure if it is better to have a weaker radio with bigger antenna or a stronger radio with a smaller antenna.......

Good luck!

YellowLemon writes...

Is it 24dBm("250mW") + 12dBi = 26dBm("4 Watts") ????

24 dBm + 12 dBi = 36 dBm EIRP. They add up :)
[edit] and 36 dBm = 4 W so you probably meant to write 36? typo :) [ /edit]

but not sure if it is better to have a weaker radio with bigger antenna or a stronger radio with a smaller antenna.......

It's better to have better antenna because you get antenna gain on received signal as well, not just transmitted signal.

A bigger antenna gives gain on received signal, very true, but if we are talking about a point-to-point bridge with the same hardware at each end.. would it still make a difference? I could perhaps argue that a sensitive antenna might even give a lower S/N ratio by picking up random low-level junk.

BTW, 34 I saw that sysKin hehehehe maths is hard :)

YellowLemon writes...

A bigger antenna gives gain on received signal, very true, but if we are talking about a point-to-point bridge with the same hardware at each end.. would it still make a difference?

Yes, look up Friis equation: received power is transmitted power times transmitting antenna gain times receiving antenna gain times the distance loss.

So, if you have identical antennas on both ends, they both contribute to received power while transmitted power is only counted once.

I could perhaps argue that a sensitive antenna might even give a lower S/N ratio by picking up random low-level junk.

Quite contrary: don't forget that high gain antenna "simply" receives from a very particular direction. The more directivity (and therefore gain) the less junk you receive since you're not receiving stuff coming from wrong directions.

Is identical Antenna's that great i thought aslong as the Dbi matched it would be just as beneficial as matching antenna's?

Pointless to me really as i have Matching antenna's but i thought it was only the Db that need to match

sysKin thanks for that information!

Yes those are good, and they even come preconfigured however you will need two of those Bridge kits (4 radios in total) if you want to set up two point-to-point links.


Yeah, I know. We might just split the total cost 3 ways. A bit over $400 each.

Lately we have been researching what to do about mounting the antenna. We could get a pre-made hills telomast or similar ($400?) but I dont think we need to spend the money. Im planning to use 3 x 4m steel poles, each slightly different diameter. Slot them together and bolt them. Mount it on the side of the shed with guy wires attached to the bolts 1/3 and 2/3 the way up. The hard bit might be aligning the antennas in the right direction.

but not sure if it is better to have a weaker radio with bigger antenna or a stronger radio with a smaller antenna.......

I have wondered the same thing, dont really know. We will try the kit (4W EIRP) and if it doesnt work, I doubt anything will (legally).

Also, we need to find out what the highest legal mast can be.

syskin, thanks for your input mate.

You'll want to be able to move it abit to tweak it for LOS, nothing to stop you from when you mount it to the shed to not bolt it but have it in a bracket to allow some movement

Our Antenna's are mounted on our Sheds fairly high so we have used a system like mounting a antenna with tense cables, once loosened you can rotate the pole which in turn moves the antenna

Pretty simple system and yeah saves a heap buying a $400 pre made one

bagurk writes...

We could get a pre-made hills telomast or similar ($400?)

You can get really cheap "Fascia Mounts" that are basically a 2-3m steel pole with an L bend and screw holes on one end for about $25 (eg at Bunnings Warehouse). Just an option, this may not be high enough for you depending on L-O-S conditions.

BenMHarvey:

What do you mean by a bracket?

also

Yeah, what are tense cables?

YellowLemon:
We need like 15m masts.

Tense cables lol i dont know if theres a proper name but its like a roof aerial when you tighten the bolts on the cable it contricts the cable in turn making it pull on the bracket locking the antenna in place

The guys at bunnings helped us out well our first attempt fell down in those big hail storms we had a few months ago

The bracket is just 2 pieces that makes a ring connected to the cables

LOL i know my explanations are poor i'll try and get a photo or draw what i mean

someone from Mr Antenna came to my house this morning and gave me some advice on the mast...

I'll just copy paste my notes... This is based on a design of using 3 or 4 steel poles (4m each, different diameters) bolted together at the joints.

First test signal with mast then buy guy wires
guy wires must be grounded 1/2 the distance of the height - from the base
need 3 lots of 3 guy wires from 1/3, 2/3, and top of mast
need bolts with a small amount of thread at the end
buy guy plates, nuts and bolts from Coulters (brisbane) or Electrocraft (nerang)
Coulters: www.djcoulter.com.au/default.asp
Electrocraft: 5596 5533
nuts and bolts must be stainless steel
cut a U or V shape into the ends of the poles for the bolts to fit (this makes it easier to dismantle, if need be)
maximum legal height: 17m from roof
LIGHTNING PROTECTION: copper rod in ground next to base of mast. cable from rod to mast.

here is the hills pdf on telescopic masts

www.matchmaster.com.au/P...%20NZ%203-06.pdf

www.hillsantenna.com.au/...roducts/B3101TTT

i am an antenna installer and have installed many of these telo masts , i would strongly suggest you do not attempt to install the mast yourself as it could and will result in damage to your house and or injury / death . Please get someone who knows what they are doing and has experience in doing this type of install

to the report

bagurk writes...

need bolts with a small amount of thread at the end

use 6 inch coach bolts with eyelets for tile roof

use 8 inch right angle bracket for tin roof

both can be zinc plated and do not req to be stainless

see here

www.djcoulter.com.au/Pro...=1041&Page=1

www.djcoulter.com.au/Pro...=1087&Page=1

masts

Mast Telo 30' $203.80 plus kit Mast Telo Acc Pack 30' $24.40

Mast Telo 40' $285.00 plus kit Mast Telo Acc Pack 40' $30.60

Mast Telo 50' $358.50 plus kit Mast Telo Acc Pack 50' $$36.70

www.djcoulter.com.au/Pro...=mast&Page=2

yes buy the gear yourself to save some cash but please get a professional to install it

do not cut anything on the pole it is designed with purpose built s pins that secure the pole in position and locking collars to ensure the can not dislodge

lightning protector is not needed as if it gets hit with lightning yer gear is going to get fried etherway , yes grounding the mast is good because it sets the mast at a theoretical zero potential and reduces noise to the coax and antennas , but as a lightning protector a box of hair would do just as good

update-

I contacted the council about the legal mast height. It turns out Mr Antenna was wrong. This is the email I got from the council:

Good Afternoon,

Please be advised that if the mast/antennae will be over 10m in height (from natural ground level) or over 3.5m in height above an existing structure you will be required to lodge a Town Planning (Code Assessable) Application through Council. The cost for this application would be $895.00 and you would need to complete the attached forms & lodge plans. If this Town Planning Application is approved, you would then be required to lodge a Minor Building Application. This is a cost of $228.50 (includes approval & inspection).

Over $1000 to get approval!! We simply cannot afford this, so it looks like our project wont be going ahead. (unless anyone has any ideas?)

bagurk writes...

Mr Antenna came to my house this morning ...
maximum legal height: 17m from roof

That did sound excessive actually. Can you stick it in a tree perhaps? (a little desparate, I know) Why do you need it to be so high, what's in the way?

YellowLemon writes...

Why do you need it to be so high, what's in the way?

trees. big 13m trees. :(