Added new tower to the stable

[Ddruid_SMP]

PoE injectors for the AP's has been completed.

Rack near complete

Redlines in rack, you can see the RG11's in the back, I wont hook these up until we are ready to switch over. I am afraid that they will interfere with my existing links.

Surge supressors, the last AP was hung today, but I left my camera home.

 

[Ddruid_SMP]

Generator is set and hooked up. It took me 2 hrs to flare the copper ends so they wouldn't leak

This is what a 20' tower section looks like after the builders drop it from 300'.

 

[Ddruid_SMP]

We had a photographer out to shoot some picture, they're big so i'll just link them.
Looking up the center
Other admin hanging a horizontal antenna
Climbers at the top working
View of tower

What has been keeping me from the tower (something is failing and need to upgrade):

The replacement (minus the switch obviously )

 

[Ddruid_SMP]

Had a chainlink fence put around the building and tower since we are having a problem with dumpers/vandals. I decided to do a little test when I went to bond the fence to the ground ring, I wanted to see how much transient voltage the chainlink was picking up out of the air. I have a 10' section of fence that is isolated when I open the gates on each end, so I bonded that section to the ground ring and left the remaining fence un-bonded. With the gates open I took a multi-meter and probed from the bonded side of the opening to the unbonded side.

The section of fence on the right is bonded, you can see the jumper from the top rail to the post where the probe is wedged. The section of fence on the left is un-bonded and is about 100' long.

The results:

Voltage (DC) Miliamps

.5amps and 40Mw!

This is a good example as to why it is sooo important to bond everything together. It also shows why it is important to use shielded cable and bond the ends when going between two buildings on different ground systems. If you dont you can have voltage flowing across the cable and into the network equipment..

 

[Ddruid_SMP]

Still working on the 'B' link, It is not quite ready for traffic yet. Today we replaced the antenna on the big tower with a dish, it improved the signal from -80 to -75, still not quite there though..

PacWireless 28db 2' 5.8ghz dish

 

[four4875]

lookin good man... id love to have the chance to work on that... "real" tower.. haha.

you know of any resources to do readin on the diff equipment and stuff? i need to do alot of reading..... in my opinion our network needs rebuilt.

 

[Ddruid_SMP]

lookin good man... id love to have the chance to work on that... "real" tower.. haha.

you know of any resources to do readin on the diff equipment and stuff? i need to do alot of reading..... in my opinion our network needs rebuilt.

It is really difficult to find out about specific equipment, and I've only read one book about wireless and I wasn't too overly impressed, it covered the general stuff, ie channels, frequencies, polarity, fresnel, etc but nothing of what I've felt to be very indepth. You may want to subscribe to the part-15 wisp list, there are some very helpful people on the list. You may want to consider attending a wisp-con or wisp-nog.

To find out information on specific hardware it's usually best to poke around the manufacturers website..

 

[four4875]

i know the basic rf stuff with antennas and freqs ad stuff... i used to be into cb / ham radio a little.

i guess something i might wana read on is the fresnel stuff.

where can i join that list at?

edit: and are those poe injectors.. a standard? if so do you know the standard and have a link to where i could get them? i tihnk i saw them on the site you linked me for cb3s, not sure tho.

 

[Ddruid_SMP]

i know the basic rf stuff with antennas and freqs ad stuff... i used to be into cb / ham radio a little.

i guess something i might wana read on is the fresnel stuff.

A cheesy drawing I did of fresnel a while back..

Fresnel describes how the radio wave is distorted over distance. In simplified terms, as the distance between the two antenna increases the radio wave becomes 'taller', how much the wave is distorted is a logrythmic function of frequency and distance. For a successful link, at least 60-80% of the FIRST fresnel zone must be unobstructed. For example for a 5 mile link at 2.4ghz the total fresnel radius is 52', so the radio signal is 26' above and below the centerline between the two antennas at the mid-point distance wise. So to establish a reliable signal your antennas must be at least 22' above any obstactle that is at the mid-point. The same link at 5.8ghz will only have a total fresnel radius of 34'. The shape of the fresnel is eliptical, so objects closer to either antenna do not need to be cleared by as much distance..

where can i join that list at?

Part 15's lists

edit: and are those poe injectors.. a standard? if so do you know the standard and have a link to where i could get them? i tihnk i saw them on the site you linked me for cb3s, not sure tho.

Thos are just standard injectors, found here.. I am using an 18v 10amp power supply that I purchased from mouser to power the radios.

 

[Ddruid_SMP]

Been some time since I have updated this. The tower is up and going (has been for a couple months now). We have extended our coverage radius by about 1.5-2miles. Most customers gained about 6-10db in signal strength, and some did not have to move the antenna, but most did.

Another PoE shelf was needed:

Ethernet suppressors & redline suppressors:

On the tower is currently 4 wrap boards (5 AP's), 1 routerboard 532, and 2 redlines.

Redline IDU's mounted (now hooked up)

 

[four4875]

looks nice. We'll hopefulyl have our rb532s in on monday, then we shall start phasing out brilan and karlnet for mikrotik, and getting rid of MANY headaches. maybe after that some leased space o na real tower will be in order. probably not tho.

 

[AMD Phreak]

Lookin good man. Keep up the work!

 

[shellshock]

wow! very intersting. Got a couple of nOOb questions for ya

what are those "redline" panels? Do they send or receve singals? what, in general do they do lol

And, how old is that facility, and what did it brodcast, I know what you said about, the wireless cable or somethin, I was just wondering a little more in depth

Thanks for this thread, its uber interesting, lol, i just read this whole thread, woot

EDIT: one more question, what are those waveguide thingies, and what do they do?

 

[Ddruid_SMP]

wow! very intersting. Got a couple of nOOb questions for ya

what are those "redline" panels? Do they send or receve singals? what, in general do they do lol

Redline is a brand of radio, they operate in the 5.8ghz range and have a wireless capacity of 36Mb/s Half-Duplex. They are older units (4 years old), we got them when they were bleeding edge, there are radio's out there that will 100+Mb/s full-duplex. Redlines are considered a 'carrier' class radios meaning that they are capable of delivering '5 9's or 99.999% uptime. Our longest redline link is 27 Miles long.

And, how old is that facility, and what did it brodcast, I know what you said about, the wireless cable or somethin, I was just wondering a little more in depth

The tower and building was constructed in 1997 at a cost of $250k. We were told that the total cost of the equipment that was inside was about $70k. They never went on air, they had just gotten their license when the partnership fell apart. The tower & build was locked in a lawsuit for about 5 years before it was auctioned and we bought it. I actually shut off the equipment as it was still transmitting (though likely not working). The sad thing is that the guy is trying to sell the equipment and has been offered only about $5k for it.

Thanks for this thread, its uber interesting, lol, i just read this whole thread, woot

EDIT: one more question, what are those waveguide thingies, and what do they do?

Waveguide is a conductor of microwave, much like a coax cable works for your cable TV. As a signal traverses the cable it is attenuated (loses power), the amount of attenuation is dependant on a number of factors, cable type, frequency, and cable length. We do not use waveguide much so I can't explain all there is to it, but basically in a waveguide the signal is broadcast and 'directed' through the cable itself rather than travel on a conductor. Therefore the waveguide has a much lower loss per foot than say LMR400. Again I don't use it much. For us (Wisp's) we are restricted to such a low power (4watts w/an omni) that we cannot afford the cable loses, which is why you typically see that the radios themselves are mounted on the tower and there is a short piece of LMR cable (5' or less) between the radio and antenna.

 

[shellshock]

so on there cable brodcasting, they were using microwaves, like the old at&t long line system, with the wierd horn antennas? The wave guide runs into those thingies?

 

[Ddruid_SMP]

so on there cable brodcasting, they were using microwaves, like the old at&t long line system, with the wierd horn antennas? The wave guide runs into those thingies?

They use 2.5ghz (licensed), I believe signals in the 1ghz-30ghz range are considered microwave. I do believe the long line systems were infact microwave but at a licensed spectrum so that they could pump out the power to go the longer distances. I've seen several different type of feed horns on the at&t towers, I'm not sure if it is waveguide to their horns, actually I think those things are reflectors of some sort.


Here you can see the waveguide come through the wall. If you look at the silver/aluminum thing (multiplexor?) that sits ontop of the rack you'll see a smaller heliax (waveguide) cable attached to it and hanging in an arc up and to the left. This smaller heliax was attached to the larger waveguide at the termination point.

Here you can see the waveguide and its termination connector:

You can see the antenna's they used in the lower end of the picture. Their Omni antenna is the long green cylinder (under the grid), which is about 6' long and about 6" in diameter. The grid is what they would use at a customers house

 

[Archer36]

All I can say is WOW after reading/looking at the pics. I never knew so much work went into those things, but it all makes sense with the grounding and all. Looks like you do a heck of a good job, I wish I could play with all those cool toys

I have done a little bit with 2.4ghz antennas not much at all, just on personal hobby and wow still didn't know what some of that technical talk was . This is mostly new to me since AFAIK we have no Wireless ISPs in the area, and have only been in a few data centers.

 

[AMD Phreak]

FWIW we have a site that runs off an old long-lines tower. The site uses 100% waveguide up to the cornucopias. The equipment is linked to the connection point on the inside to outside via flex waveguide or hardline depending. Then from the outside its done via flex waveguide, which travels to the base of the tower into a hardline polarization coupling, which changes the polarizaton of the signal before it is injected into the actual hardline that travels to the feed horn which is at the base of the cornucopia.

Most microwave is not very high power, the typical power for AT&T sites was at most 10W according to what i can find on the web. However, this was at frequencies from 4, 6 and 10 or 16 i believe or round abouts. Not to mention the 40-48dB of gain from the cornucopia itself..... not something I would fancy spending any time in front of at any point. If this was a TV broadcast tower, that omni would have some considerable power fed to it, and you'd probably get baked alive if you climbed to the tower and got near it. RF is fun, but at the same time you have to be very aware of what exactly is coming out of the antennas.
/end threadjack

 

[Archer36]

but at the same time you have to be very aware of what exactly is coming out of the antennas.
/end threadjack

Yep like don't look directly at them up close or risk loosing your eyes!

 

[stereo555]

WOW ....this is one of the best threads Ive ever read here at OC .

Thanks Ddruid_SMP for all the cool pics , learning info (all-be-it , alots over my head with a project this large ) .

You've done alot of good hard work ..... I wish you the best for SUCCESS !