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10.12.05

 

Limit Site Liability - Inspect!

by John Bisset

When was the last time you visited each of your transmitter sites - when it wasn't an emergency?

During a recent discussion with a group of engineers at the Nebraska Association of Broadcasters, everyone agreed transmitter site inspections aren't as commonplace as they were, say, 10 years ago. But forcing yourself to spend a morning or afternoon just walking the site can be beneficial.

Fig. 1: Even a temporary tower can wreak havoc with an AM directional.

Here are some things to keep in mind.

Make a list

Fig. 2: Keep locks well lubricated, especially with cold weather approaching.

As you drive to the site, write down a list of clear driving directions. Include full street names, turns and mileage. Posted the document at the studio control point, in the event the engineer is unable to drive to the site. Also list the "official" 911 address so emergency crews can be dispatched easily.

As you drive to an AM transmitter site, keep your eyes open for new construction, especially new towers or cellular monopoles. New construction can seriously affect directional patterns, and early detection is the best policy. That's a portable monopole erected near an AM directional, in Fig. 1.

New towers are usually not an issue for FM sites unless the new tower or antennas are being erected within the FM antenna aperture. If you lease tower space for your FM, periodically view your antenna with binoculars or use a camera with telephoto lens to make sure other antennas have not invaded "your" space.

Before you even go inside the transmitter building, a thorough exterior inspection is warranted.

Fig. 3: Properly identified towers include a tower registration number.

First, check gates and fences for security. Note the results of this inspection on the maintenance log or contracting work order. Contract engineers, this kind of inspection can be value-added or a source of additional revenue for your client.

Open and close all locks with keys, making sure they operate freely. Make sure no locks are missing and no gates are open. Spray WD-30 or liquid graphite into the lock, working the lock (opening and closing) and tilting it so lubricant coats the internal parts. Look for holes cut in fencing; missing chains or hinges; torn, ripped or missing razor/barbed wire - any signs of attempted intrusion. Document and take pictures of any intrusion; the pix will help document claims. Keep locks in good shape by lubricating the working parts.

Also before entering the building, conduct a visual inspection of the exterior; walk all the way around. Check for missing or broken windows, water damage, holes in walls, missing or broken flood lights, graffiti or other indications of vandalism. Notify police of problems discovered, asking for a copy of the police report, which will be useful should an insurance claim be necessary. Make a notation in the maintenance log or contracting work order.

Make sure there are "Danger High Voltage" signs on the tower fences and that each tower has a sign affixed listing the FCC-issued Tower Identification Registration Number. This is required by the commission. A secure tower fence is shown in Fig. 3.

Take your greens

Are transmitter air intakes or air conditioning condenser units clear of weeds and vegetation? Such growth not only blocks air flow, reducing efficiency, but also retains moisture and serves as shelter to rodents. The solution? Mow around the building or use Roundup or similar inhibitor to prevent weeds from growing around the building.

Fig. 4: Control vegetation, especially around air conditioners.

An alternative is to lay a 4-foot perimeter of landscape fabric up to the building and cover the fabric with clean, crushed stone. You may be able to trade these services with a local lawn or landscaping company.

Inspect the roof for missing shingles or tiles, signs of leaks or broken flashing.

Check satellite dishes for bird and bee nests in the feedhorn, loose hardware, loose anchoring bolts, anchor wires and loose mounts. Cap open feeds. A waterlogged feed is as useless as one hosting a bee's nest.

Look for any sign of vandalism to the dish, including attempts to tilt or move it. Mark the dish pole and the anchor pole with a Sharpie marker so any side-to-side rotational movement is obvious. Should the dish be moved by vandals, these marks will make resetting it easier; simply move the dish back till the two lines line up, one over the other.

While inspecting the satellite, check for missing sections of the dish material and for out-of-round shape caused by snow or ice buildup, which bends and deforms the dish. Deformed dishes will produce weak or nonexistent signals because the beam is no longer focused into the LNB. Remember this when it snows or the dish ices.

The brush-off

Fig. 5: Inspect satellite feedhorns and cap openings.

Keep your dish clear by sweeping it with a broom. Don't bang on the dish as this may deform it. Gently sweep snow and ice out.

Treat a dish with car wax to help keep snow and ice from sticking to the dish surface; a broom then will swish out the snow and ice quickly. This is a something a contract engineer can offer other stations with dishes.

This can be developed into a contract maintenance service: "We will mark your dish settings, inspect for loose or missing hardware, spray the feedhorn for bees/birds and wax the dish for easier snow removal." Any savvy station owner knows it is cheaper to prevent the problem than lose listeners and revenue when the dish is out.

As you inspect the dish, also check the coax from the feedhorn. It should not be bent, chipped or split. If the coax goes into a pipe, seal the entry with dum-dum or expanding foam and steel wool. Is the RF connection to the LNB sealed with waterproof tape? Are black wire ties used to secure all the cables? (White wire ties will break when exposed to ultraviolet radiation. Do not use them outdoors for any application.)

Make a notation of utility pole numbers and the location of water meters/main shut-off valves. Combine this information with the station account numbers and emergency utility phone numbers. Keep a copy of this information at the transmitter site and station control point.

We'll review more inspection tips next time, and we welcome yours to jbisset@bdcast.com. In the meantime, after you've conducted this outside inspection clip this column and pass it on to your GM or owner giving the site a grade of A+ or providing a list of what needs to be corrected.

Your inspection demonstrates a proactive approach to protecting their investment.

John Bisset has worked as a chief engineer and contract engineer for more than 30 years. He is northeast regional sales manager for Broadcast Electronics. Reach him at (571) 217-9386, or jbisset@bdcast.com. Faxed submissions can be sent to (603) 472-4944. Submissions for this column are encouraged, and qualify for SBE recertification credit.

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