The two "U" clamps holding the dish are slightly twisted.
Once I tie myself off with a safety belt, I don't have to keep one hand on the ladder, or risk my life using both hands on the antenna. Throw an 11mm rope over the roof and tie it to something really sturdy. Get a safety belt, sit harness, or just tie yourself off with more rope. Then, you get to use both hands.
No such thing. Shove some clear silicon waterproofing grease (the same stuff used by the phone company) into the RJ45. The best place to find that is at the local scuba dive shop. It's used to seal camera housings. Don't use too much. When done, just wrap some clear cellophane wrap around the coupler, and then embalm it in electrical tape. If exposed to sun, spray with clear acrylic to keep the tape from crumbling.
Learn by Destroying(tm). Remember, you have only one life to give for this project.
No. Parachute cord is too thin and too bouncy. Tie some to a tree and put your weight on it. Notice how it stretches. The local ACE Hardware stores have 100ft lengths of shoddy 11mm rope in assorted garish colors for $10 to $17. However, for stabilizing the ladder, yellow polypropylene utility rope (wire pull rope) is good enough.
I've seen the results a few such sideways slips. Usually, it's from improper placement of the ladder legs. If one ladder leg goes into a gopher hole, the ladder (and you) will go sideways.
I've also had it happen to me, when I put a ladder leg onto a knot hole on my redwood deck, which popped out and sent the ladder sideways. Fortunately, it wasn't very high and I broke my fall by ripping out the rain gutter (and shredding my hands).
As I mentioned, the two clamps are slightly twisted. It's not enough to make any difference, but it just looks odd.
Well, LTE has been on the local SLV cell sites for about 9 months.
Samsung SCH-LC11
I played with one last weekend. Connection via Wi-Fi was erratic and would frequently disconnect. It does some strange dance for about two minutes when first turned on. It looks like it's ready to use, but it's not. No special software needed. No diagnostics or signal strength indication. We were in a fringe area for 4G, so speed was slow.
There's also a USB 4G device. No 3G so if you're travelling, you may have coverage problems:
Just read the reviews and draw your own conclusions. I haven't had time to try it.
It uses WiFi from the hot spot to the computers. My cell phone will do the same but its range is limited and I really don't want to hang it on a pole outside.
I've been told that we can rubber band our cellphone to the head of a Dish TV antenna, which is a portion of a parabola, which will amplify the cell phone signal.
Yep. The DBS satellites are 3 degrees apart across the ecliptic. If that was the only criteria, the dish pointing accuracy would need to be less than +/- 1.5 degrees. However, there are multiple birds in each satellite slot, which means too narrow a beamwidth can become a problem if a bird drifts too close to the edge of the slot. I found that out the hard way when I tried to use a 3 meter dish for DBS reception. With the worm gear adjustment on the dish azimuth, I could individually pick out which of the 5(?) birds were in the 101 slot. Too narrow a beamwidth is NOT a problem with most DBS dishes. The feed horn and dish parabolic contours are designed to give about a 2.1 degree -3dB beamwidth, which is what's needed to cover the entire 3 degree slot. However, for that to work, the dish has to be aligned to something like +/-0.5 degrees. It can be done, but it takes LOTS of practice and patience[1].
Well, I bought one for my Droid X for only one stupid reason. I wanted an easy way to determine if I had a chance to shoot through a hole in the forest canopy. I think you've seen my 101 hole:
With the Droid app, I can take a photo of the tree canopy from a prospective antenna location and mark where the satellites should be. I then send the JPG to the tree trimmer and mark where to trim the branches. That's not a problem you'll have in the flats, but in the forest, the app is quite useful.
I've never bothered to run my own setup. I'll post a photo when I have time.
[1] I fixed one install where the dish was on the roof, near the edge of about a 4ft overhang. I'm on the roof doing the adjustments and getting good signal. As soon as I climb off the roof, the picture and signal fall apart. I climb back on the roof, and it's back to normal. What was happening was the roof was bending very slightly from my weight. I moved the dish back from the edge to the middle of a load bearing wall, and everything stayed put.
Another nightmare was a dish on a pole set in concrete. The owner said that they had to realign the dish every few months. The problem was obvious. The hillside was a slow moving avalanche. It eventually collapsed into a ravine a few years later.
Agreed. Even a Rohn 25 is self supporting to 20 ft. Same with a 10ft steel pipe. I start using guy wires at 20ft and up.
Before a falling tree in Feb 2012 trashed all the antennas on my roof, I had a 10ft pipe with a mess of antennas on top, that was supported by three guy wires. Because it was a tilt over base, the guy wires were mandatory. I was constantly tripping over or walking into the guy wires. I'm going to replace it with a tripod base, which doesn't require guy wires.
Sorta, kinda, maybe. It's true in urban jungles and areas with lots of GSM/UMTS cell sites. Not true for forested and rural areas.
GSM has a fixed maximum cell site range of 120 km,[5] which is imposed by technical limitations.[6] This is expanded from the old limit of 35 km.
By implementing the Extended Range feature, the BTS is able to receive the uplink signal in two adjacent timeslots instead of one. When the mobile station reaches its maximum timing advance, i.e. maximum range, the BTS expands its hearing window with an internal timing advance that gives the necessary time for the mobile to be heard by the BTS even from the extended distance. This extra advance is the duration of a single timeslot, a 156 bit period. This gives roughly 120 km range for a cell.[3] and is implemented in sparsely populated areas and to reach islands for example.
It will probably do some good at 1900MHz and not much good at 850MHz. Anything is better than the stock internal low-SAR antenna. You would look rather odd wearing a satellite dish on your head. A flat piece of sheet metal or aluminum foil will work almost as well as a dish.
Let's do the math. A DBS dish is about 0.6 meters wide. At 850MHz, the maximum gain for a parabolic reflector is: gain = 9.87 * Dia^2 / wavelength^2 * (feed efficiency) gain = 9.87 * 600mm^2 / 353mm^2 * 0.4 gain = 11.4 dBi = 10 log(11.4) = 10.6dBi At 1900MHz, the gain = 17.5dbi
The 40% feed efficiency (that's the 0.4) is probably optimistic. That's also if everything is lossless, perfectly matched, built correctly, and properly designed, which is not the case for hanging a cell phone on a DBS dish. In receive, all of the RF that hits the reflector from a distant source hits the dish and is reflected toward the cell phone. Therefore 10.6 and 17.5dBi are the maximum receive antenna gains.
However, it's much worse in transmit. The cell phone transmits RF in all directions. With an electrically shortened antenna, it's almost a spherical pattern. Only some of that RF hits the dish. Most of it flys off in useless directions. The percentage is the area of the dish divided by the surface area of a sphere at the same distance from the dish focus. The area of an 600mm dish is about: Pi * 300mm^2 = 283,000 sq-mm The surface area of the sphere is: 4 * Pi * radius^2 = 4 * 3.14 * 350^2 = 1,538,600 sq-mm Therefore, the percentage of RF that actually hits the dish from the cell phone antenna is: 283,000 / 1,538,600 = 18.4% In terms of antenna gain, that's a loss of: 10 * log(0.184) = -7.4dB Therefore, the transmit antenna gain will be no better than: 10.6dBi - 7.4dB = 3.2dBi gain (850MHz) 17.5dbi - 7.4dB = 10.1dBi gain (1900MHz)
That's an improvement over the internal antenna, but hardly worth the effort at 850MHz. Not too horrible at 1900MHz. However, you can do better with an external antenna connector and a high gain yagi, panel, patch, other cellular antenna, or just a bigger dish or plate.
As you probably know, you can spot slides with trees. Trees just don't grow at angles. We may not have forests to deal with, but lots of sliding land around the bay.
It is tough to get better than 3 degrees out of a cell phone or GPS flux gate. It seems to me you would have to trim a lot more trees than needed to get your window.
I'm curious what the next step above a Lensatic Cammenga (+/-2.25 degrees) I see some boating flux gates spec 0.5RMS. Now that means if you want +/- 3 sigma, you are at +/- 1.5 degrees.
There is some irony that the best compass you can buy is probably a big dish and a geosynchronous satellite.
I live on a hillside. Plenty of trees simulating a slow motion mud slide. I have one oak that I've been watching for about 30 years. I think it's time to take it down before it creates a big problem.
I can get very accurate during the bi-annual "solar outage"
in late Feb and late Sept. I can't use it to aim the dish, but I can use it to see where I should clear the tree branches.
Dunno. I don't use a compass. I get the dish vertical with a bubble level. I preset the elevation and the skew (for dual LNB's). I then just spin the dish around the best guess azimuth. Works every time.
I think a GPS receiver is just as accurate for speed and direction. I've ridden on a straight road and noticed that the GPS indicated direction was absolutely stable and never changed.
GPS direction is basically computed from waypoints as you move. [The FCC has a web page to get the bearing between two waypoints. The GPS does a similar computation.] But getting a bearing at a fixed location means you aren't moving. ;-)
The higher end GPSs have fluxgate compasses because if you aren't moving fast enough, the GPS can't compute the bearing. I gather even without SA there are time dependent errors in the GPS signal. Hiking up a steep hill usually slows you down, so the differential waypoint technique starts to get very inaccurate. The GPS will switch from the virtual compass to the fluxgate compass based on the speed estimate.
It you take a GPS and "park it", but log the trail based on raw readings, you can see the location wander. Some GPSs filter this wandering since people are confused if they are still and the GPS indicates they are moving.
There is a lot of "enhancements" in GPS tracking that can fool you into thinking the GPS is better than it really is. For instance, if the GPS has mapping, it will snap onto a road even if the actual position is off a bit. Once in a while this scheme can snap onto the wrong road.
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