Broadband ISP Photos → The inside of a tap

In case you were curious: heres the inside of a Motorola tap.

This is a basic one that can serve 2 houses. You might find this in a pedestal on the ground, though im sure the aerial ones aren't different at all Enjoy.

P.S. if anyone has any other pics of the insides of a tap, post them! Or if you would tell me techincally what happens here at the tap.

From my understanding, the thicker copper cables (serving at 1ghz frequency?) that run up and down the street connect to all the taps serving the houses.... and from the tap runs regular RG6 into your house... but what is that tap doing when it goes from a thicker cable to a RG6? Cause you may notice theres a green chip in there... and the little blue chip too (size of a quarter) that comes out of the slot it sits in.

There is DC power present on the aerial or underground coaxial cables, the tap prevents that DC power from entering the customer's drop. The power in the coaxial cables powers the nodes and amps.

So am I correct to guess that a tap does more than just split signals like a splitter? How do they know what cable serves what customer back at the headend?

This is what I've always wondered. I'm not too savvy on this topic, so I may be asking a hugely broad questions.

Is it the cable card that goes in your receiver that allows them to differentiate your service from, say, your neighbor's service? And how are they achieving 2 way communication on coaxial?

It's AC power not DC Generally 60 VAC in VOIP, and 60-90 VAC in NID powered telco markets. Taps can and are designed to not only pass AC across the tap but also through the drop ports. These are mostly used in "powered NID" systems.

A tap is a DC (directional coupler) with a cascade of two way splitters in it. Depending on how many ports are required dictates how many "splitters" are on the tap. These aren't two way splitters in the classic sense as they are in the PCB rather than physical splitters.

They generally use tags on the wires labeling which are going to what house. They don't really have way to tell which wire does exactly what, but good ethics and proper record keeping goes a long way.

Forward path signals travel on a QAM in the higher band frequencies.(88-860MHZ) The modem "talks" back to the headend on 5-40Mhz(or 5-65Mhz in Europe). Wires don't really care what frequencies are in them or what direction they are traveling they are simply the conduit. Amps, do care and since the HFC is comprised of many amps they have a specific workaround. This involves "diplexing" the signals separating them. At that point the "Amp" has two separate but distinct amps, the forward path high gain amp, and a simple low gain return amp. After the signals are separated they travail "across" the amp and are combined back to together on the other side for the ride across the coax to the next amp.

i'll post pics of the taps we use later

Hey jay you guys dont use the addressable taps do you?

Only three bolts now. Looks like they are making it easier to change out when the tap goes bad. Looks more weatherproof now also.

charter just replaced my tap cus i was having upstream signal problems and bad cable tv reception. once he replaced it upstream settled around two 42 and downstream power went up two 19db. the inside of that thing was interesting he replaced it with a 2 port one instead of a 4 cus there no houses around me.

alex