I Installed Wifi 900 Ft Underground In An Abandoned Mine

Glad to see you've enabled password protection on your wifi... you don't want miners piggybacking on your network!

Once you start spening time down there regularly i recommend switching the lights from white to red at "night" time to keep your sleep cycles regulated.

as a professional Network engineer, i would have looked at using multi-strand single mode fiber (think a single cable with multiple strands of fiber to splice off of) to each level that is significant to you, such as the 900 and 700 foot levels. This way you terminate a pair of fiber at each level then add a POE switch to covert to CAT6 ethernet and provide the Power over Ethernet to run the Access Point. This method is highly extensible and creates a consistent, repeatable network for each level. The draw back is money, your method is a lot cheaper. Ether way glad to see you have connectivity down at the 900.

If you are going to spend a lot more time in the mine, you may want to provide some forced air ventilation down the shaft to dissipate Radon, which is seemingly everywhere underground and a serious health risk. It may largely settle into the deeper shafts to decay, but you should measure it to find out what level of risk it adds to the mine adventure and whether or not it can be reduced by forced through ventilation of the same type used in working mines.

RG6 is only good for 327' after that signal is lost. either use repeaters or RG11 might work but that might even be to far....Id use fiber!

You should have an emergency backup for communication like a simple crank phone. One down at 900 feet and one at the top. Crank rings bell, answer and talk. Small rechargeable battery to power the system. All cheap and available.

Next up: IoT environmental sensors. Particularly a 4 gas meter. Looking at all the dust floating around there, dust masks should be part of the long term stay plan as well. Having power down there to recharge portable work equipment light lights is also really helpful. Since this room is sort of your hub of activity down there, you may want to put in a network switch, with the wifi on one port, and more coax converters to split off into different sections of the mine. Another possibility is just to drop SEVERAL coax lines and toss the boxes into the landings on different levels so you are ready to hook up when you start exploring that area.

I am a ham radio operator and it has always been a Standard Operating Procedure when running ANY long run of ANY type cable or wire to ALWAYS do a continuity check on EVERY section to make sure you have a good cable or wire as well as all the electronic devices. Hook it all up BEFORE running even the first foot.

This would just blow the minds of the miners 100 years ago. You are now connected to a system that allows you to read pretty much every book ever written, listen to virtually all music ever recorded, watch images from around the word as they happen, access to all books. All 900 feet down a mine. Wow

This makes the mine so much safer & gives me piece of mind when you're down there alone

Sorry for the LONG comment! Hi Brent, Congratulations on getting internet to the 900 ft level!! If I may, I’d like to suggest a couple things. 1. Add a POTs (Plain Old Telephone) line so you cane have a “ring down” phone by using the Viking DLE-200B below. All you do is pick up the receiver on either phone to make the other phone ring. I currently have this setup and it works great. The Viking® DLE-200B™ Emergency Telephone Ringdown Circuit produces two-way communication between analog telecom devices by simulating an analog phone line. Popular applications include dedicated point-to-point communication and telecom equipment demonstrations without a phone line. 2. Considered upgrading the Coax connection to Fiber connection. Fiber has Much, Much lower losses than the coax does! If you ran RG59 coax that is very close to the limit of those devices, see below. Using fiber optic cable does have its drawbacks but the coax also has limitations. Cable Supported 75 Ohms coaxial (other impedances supported) Transmission Range Up to 1100' (300 m) on RG59 or 1600' (500 m) on RG11 at full rate Fiber optics cable can also support several other things at the same time such as video to monitor the water. This way you want take up the Wi-Fi bandwidth for video. Since you have power you can add a power supply with battery backup at the 900 ft and other levels as needed. If the “Head End” also has battery backup your internet connection would still work even if you lost power top side. Ron, N4PHP

Thats great news, might I suggest a dedicated phone that stays down there with a charger. Also put in some emergency lights that go on when the power is off, and a battery charge system. Don't forget to encapsulate all those components with plastic to avoid moisture condensation on the components. Have a great week and God bless amen.

Ships and mines sometimes allow for walkie talkies by running a network of leaky feeder cables between spaces, which is coax with intentionally leaky shielding, so that it can absorb RF signals in one space and transport them to other spaces to be re-radiated by deliberately leaking the absorbed signals. I've also heard it called half-shielded coax. Ships also often have sound-powered telephones, which can work even if the ship completely loses electrical power. Both systems can range from very simple to very sophisticated.

Could probably have tested everything up top. doubt it makes a difference if the cable is rolled up on the roll or going down the mine shaft.

With having power at each level, you may want to consider having POE network switches plugged into each of those outlets at each level so that you can add IP devices (access points, IP cameras, etc.). That would also allow you to use more traditional networking cabling (CAT6) since you wouldn't be exceeding the distance limits from CAT6. The reason for using the RG6 COAX over CAT for that 900ft distance is obviously that RG6 is limited to about 3280 ft because you lose signal (and power) the farther it goes. Using something like fiberoptic wire from top to bottom would mean you didn't have power over the Coax, but since you already have power running down there, that shouldn't make a difference. You could also consider a directional WiFi access point that goes straight down the shaft so that you could potentially get WiFi all the way down too (these are typically used for point-to-point WiFi bridges, but maybe there's one that would work for your needs too?) Another thing to consider is a VPN system, so that the devices on that network act as if they are on your own network in town. That way if you needed to connect IP cameras to a NVR, or other monitoring device, they devices in the mine would think they were connected to the same network in town... that became an issue for you. I'd love to see Ubiquity work with you to show how their rural and long-range systems can work for residential and commercial applications with sponsored content. Imagine having WiFi for the entire town, and show how it's all managed through Ubiquity Routers, Switches, Access Points, and their management system. I think it'd be a great collaboration.

Congrats!! Not only did you get internet on the 900 level but it's also pretty dang fast for all the relays it has to go through. So cool!

For your dedication in preserving American History, CA and Los Angeles; you should be awarded and recognized by the Smithsonian and/or other organizations, after all is done and/or now. Love what you are doing. Way to go Brent! 👍👍

That's awesome! Yeah, power via a 900ft coax cable was always going to be problematic. The longer the wire, the more resistance and hence a reduced current. So a thicker power cable is needed. Can't wait for the exploration that this will make possible! Tread carefully my man

Way to go Brent! Your perserverence always pays off! Congrats!

Way to go Outstanding!!! 🎉 and good luck with all other endeavors.