Experience with tower installation?

I have access to a 150 ft tower to add a gateway at a university. Anyone have a recommendation for antenna and cable?

I was going to use a laird 3dBd (25 in) or 6dBd (61 in) antenna and either LMR400 or LMR600 cable with lightning arrestor.

Cost is of some concern… but paying a tower guy to climb the tower is likely the most expensive.

If I knew the gateways were reliable id just have him install the gateway on the top of the tower… but repeat climbs ste expensive.

Any thoughts?

Hi @everhamme, 150ft of LMR-600 will lose you about 4dB which is not too bad so locating the gateway at the base is practical.
I would use a 6dBi antenna but don’t be tempted to go further. Keep in mind that a 6dBi omni antenna will create a zone close around the base of the tower that will have poor service. Check the vertical antenna pattern.
Make sure that the antenna is on a pole or boom to keep it at least 1m (3 ft) from any structure.

To keep maintenance costs down, focus very hard on three matters;

  • First, the quality of the mechanical install to ensure that the antenna will not come loose from vibration, wind, etc.
  • Second, the connection of the antenna to the LMR-600 cable. I assume that it’s N-type. Use a professionally terminated cable and then seal the connection and use self-amalgamating tape. Do this on the ground. This prevents water penetration.
  • Third, very careful cable install to prevent damage.

Put the Lightning arrestor at the base of the tower.
Good tower riggers know how to do all this but some are real butchers and will cost you money for repair climbs.
Lastly, commission the system carefully and measure the performance using a number of LoRaWAN devices in set locations. Record the reported RSSI and SNR. Periodically repeat the tests to check that performance has not deteriorated.

Very lastly, I’ve sent a lot of people up towers and I have the utmost respect for them. It’s not something that I could ever do!
Tower-01

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Thanks! exactly the advice i was looking for. I install weather buoys on the Great Lakes and go through some pretty intense prep work to ensure we don’t have to visit these sites often, so weatherization and securing cables is easy for me! I think the tower guy is a ham type hack (licensed and trained though!), but 1/10th the cost of a cellular-oriented company… I’m doing a proof of concept project and need to get him all the materials.

I’m aware of the dead zone around the base… easy to install a cheap second gateway at ground level…

Great idea to do site survey after to get a good baseline. i’m aiming for maximum distance with this install to be able to blanket part of a Great Lake with LoRa!

Have a look at the new 6dBi antenna from RAK. It has about 10 degrees of downtilt at 920MHz, may provide better outcome than an antenna that’s providing 6dBi in the horizontal.

image

this one? https://store.rakwireless.com/collections/accessories/products/fiber-glass-antenna?variant=27103007408228

Hi @everhamme, I should have added that it’s best to have everything ready at the base of the tower first, then send the climber up, then do a first commissioning check while the climber is still up the tower. Only get the climber down once you are happy that the install appears to be ok.
Also, get the climber to take detailed photos of the install at the top of the tower.

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Yes, that’s the one. Compare its polar diagrams with other antennas to select the best antenna for your site.

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