TV Antennas And Reception In Apartment Buildings

A resident reports pixelating channels. Two apartments down, everything is fine.

That pattern tells you the antenna is working and something between it and the apartment is not.

How the system is built

An antenna on the roof, a masthead amplifier, a distribution amplifier, then a tree of splitters and cabling down through the building to a wall plate in each apartment.

Every splitter reduces the signal. Every metre of cable reduces it. Every poor connection reduces it. The system is designed so the signal arriving at the last wall plate is still strong enough, and it has very little margin once anything degrades.

The antenna and the distribution system are common property. The lead from the wall plate to the television is the resident's. Which is where most of the argument starts, and it is the same [common property or lot owner](/blog/common-property-or-lot-owner-who-pays) boundary as everything else.

Diagnosing it by pattern

One apartment only. The fault is in that apartment's cabling, its wall plate, its lead, or its television. Frequently the lead, and frequently a splitter the resident installed to run a second set.

One riser or one stack. A splitter or a length of cable serving that group.

The whole building. The antenna, the masthead, or the main amplifier. Also weather, and also a transmitter fault, which is worth ruling out with a phone call before anyone goes on the roof.

Some channels only. Usually a level or interference problem rather than a cabling one, because different channels sit at different frequencies and are affected differently.

Worse in bad weather. Points at the antenna, its mounting, or water in a connection on the roof.

What actually goes wrong

Water in a roof connection. The most common fault by a wide margin. Connections on a roof need to be weatherproofed properly and frequently were not.

A failed masthead amplifier, which has a power supply and a service life.

Corroded connectors, particularly on a coastal building.

Old cable. Cable installed decades ago was not designed for what is broadcast now, and its shielding degrades. A building with original cabling will keep producing intermittent faults no matter how many amplifiers get replaced.

Splitters installed by residents, which unbalance the system and affect neighbours as well.

Interference from LED lighting, a failing power supply, or a solar inverter. This one is genuinely difficult to find and it is a real cause of complaints that started the week something else was installed.

The antenna moved. Wind shifts an antenna slightly and reception degrades across the building.

Measuring instead of guessing

A signal level meter at the wall plate tells you in a minute what a week of swapping equipment will not.

Too weak and the picture breaks up. Too strong, which happens after an amplifier is fitted to solve a weak signal somewhere else, and the picture also breaks up. Both look identical to the resident, and they have opposite fixes.

Which is why the honest approach is to measure at the plate, then at the splitter, then at the amplifier, and find where the level goes wrong.

When to replace rather than repair

A building with original cabling, an aged amplifier and a history of recurring complaints is spending money repeatedly to stay where it is.

Replacing the head end and the distribution, and the cabling where it is accessible, ends the recurring calls. It is a capital item and it belongs in the plan.

Worth doing at the same time as any other riser work, because the access is the expensive part. If the building is opening risers for cabling, data, or a [stack replacement](/blog/plumbing-stack-replacement-in-older-buildings), the antenna cabling goes in with it.

The other services in the same riser

Most buildings now carry the antenna system, internet, and sometimes a satellite feed in the same pathway.

Coordinating those rather than having three contractors each add their own cable is what keeps a riser workable in ten years. It is the practical case for [one contact for the whole building](/blog/one-contact-for-the-whole-building-the-case-for-consolidation).

Ample handles antenna and distribution work as part of the electrical scope across apartment buildings in the eastern suburbs and inner city.