On Wed, 16 Mar 2016 11:55:36 -0700, DaveC Gave us:
Could be "LEO WiFi" or... Is there an airport nearby? Could be a locale marker.
Major airport 5 miles. This isn?t directly in the landing path, kinda off to one side by a couple of miles.
I see 6 coax cables up there, I'm guessing a Cell tower, with 3 or 6 directional antenna. Must be high frequency, but I can't tell the size from the perpective of the pictures.
Can you put multiple, directional antennas in an enclosure that small? I'd bet if it's cell, it is a single antenna for a micro-cell. But I'm not convinced it's cell. The area looks flat, no large buildings - I can't see any reason it would need a micro-cell.
'sa good guess. I see four or five separate feedlines.
It could be a compact "microcell" with four to six separate directional sector antennas, designed for lower visibility. Looks as if the actual radios are down in a sub-surface vault.
I doubt it's VHF or lower-UHF (e.g. police or fire) as stacking that many antennas for those bands in close proximity could result in all sorts of interference.
Smart meter hub
That?s an interesting suggestion... It is located in the heart of a large commercial/residential (single-family homes) district in California. Anybody familiar with PGE smart meter wifi?
On Wed, 16 Mar 2016 12:04:51 -0700, DaveC Gave us:
Outer marker? Naaahh... They are 75 MHz..
Nope. Much too small an antenna. 6 coax cables means 60 degree sectors, which makes no sense for a suburban low altitude antenna. Cell user driving by would end up having to switch sectors several times. It might be DAS except that DAS antennas usually use big fat heliax coax cables, not something that looks about the size of RG-6/u. It's also not a beacon antenna, wi-fi antenna because of the high loss coax, 4.9GHz police communications, or something similar, mostly because of the 6 coax cables.
Those 6 cable also beg the question of where do they go? Following the coax down the pole, it goes into a long conduit, exits temporarily just above the power meter, and goes back into a different conduit, which disappears into the ground. So, where's the transceiver? Certainly not in the antenna, which is much too small. Certainly not buried in the concrete sidewalk with no evidence of a utility vault in the sidewalk. Even so, the coax cable loss would be too at cm and mm wave frequencies.
However, the killer is the "radome". If you look at the bottom edge carefully, you'll see that it's very thin, which makes it metal, not fiberglass. Metal covers make rather poor radomes. The paint color is also fairly common for metal covers, but not for radomes.
(Insert drum roll please). My guess is that these are RG-6/u or RG-11/u CATV coax cables running to various businesses on the street. They are terminated with a power divider or possibly an amplifier, which might explain the presence of the power meter on the pole. Although an odd place to terminate CATV cables, I guess(tm) someone did it to keep curious engineers bearing screwdrivers from taking it apart.
It's a short range cell tower common in industrial areas of Silicon Valley. Those are likely power and networking cables sticking out.
I'm not sure what the slender metal box is. Batteries?
A better question is why you didn't read the sign on the other side of the pole?
Very nicely done. Nothing like that in Santa Cruz yet. I have my doubts that anyone would install a 60 degree per sector antenna that small with 6 very long coax cables possibly going to a nearby building, but it's possible. The RF hazard sign is the clincher. However, what is inside the 4 boxes hanging from the pole? Telco backhaul?
Is it a Comcast (or some other) neighborhood hotspot? There's one at the end of my street - not at the top of the pole and not so many wires but it's similar in appearance.
See if it's on the map:
Looks like you may have nailed it Griz:
That?s the exact location.
Nope. XfinityWiFi is Comcast. They configure their subscribers "gateway" boxes to allow anyone with a Comcast login/password to use the bandwidth. They do not install poletop wi-fi repeaters or access points. The address shown is Live Wire, which is the Comcast cable internet subscriber:
Mesh networks usually use omnidirectional antennas. Put a directional antenna on a mesh and it will only work in that direction. There are some 120 degree sectorized panels, which when combined in threes, forms an omni. These are also use to monopolize all 3 non-overlapping2.4GHz wi-fi channels (1, 6, and 11). The 6 coaxes might be two polarizations per panel, times 3 antennas.
Just to complexicate things, Alvarion sells a similar system, where the RG-6/u coaxes feed RF at about 70Mhz(?) and up/down convert to/from the desired 2.4GHz channel in the antenna. However, they use much nicer looking and larger sector antenna.
I found this DAS (distributed antenna system) install that looks somewhat like the San Jose photo: The antenna radome is the same color and about the same size: and the battery pile looks something like the one in the San Jose photo: but with only 2 coax cables and a much neater installation.
PG&E has two types of smartmeter (meter reading) systems. The electric meter system runs on 900MHz FHSS (frequency hopping spread spectrum) in the form of a mesh network. There are a few pole top access points which transition the data from RF to a wire line or fiber backhaul. The San Jose photo might be one of these systems as60 degree sectors would allow for considerable frequency reuse, which would be very useful as the traffic tends to increase substantially near the wired access points. The natural gas system runs on about 162Mhz(?) as NBFM (narrow band FM) and is also a mesh. The antennas on the pole top access points look like larger vertical fiberglass base station antennas.
That's also my question. All 6 coaxes appear to transition from the upper long pipe, to a pipe going into the ground. There's no below ground equipment vault, so where do they go?
I can't tell which of these signs is in the Google street view photo: This one looks like a possible match:
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