(click thumbnail)Fig. 1: Keep high-voltage capacitor insulators clean; discharge them first.Heading to the transmitter site? When was the last time you looked inside that big old rig? After powering down, throwing the circuit breakers and contacting all components with the grounding stick, grab your trouble light and look at your power supply capacitors.
Fig. 1 shows the dirt and grunge that can lead to a flashover. After you've contacted both terminals with the grounding stick, use a clean rag soaked in isopropyl alcohol to clean the insulators. Inspect the terminals and make sure the wire crimp is solid, that the nuts are tight and no fluid is leaking. A leaking capacitor will soon explode; replace it!
As you inspect your capacitors, look for discolored terminals, such as that seen in Fig. 2. These signs of overheating can lead to potential failure. Anyone who has cleaned up after a capacitor explosion will tell you it's a nasty job. Spend the money to replace the capacitor before it explodes.
Ben Hill is chief engineer of CBS Radio's WIP(AM) in Philadelphia. He adds his cautionary word to our discussion about subcontractors digging at transmitter sites.
The water department needed to restore service to the WIP transmitter building after having billed the station - for at least five years - for water service that wasn't provided.
They used a device called a "shooter," a steel rod inside a PVC tube. Air is forced into tube and the rod blows through the soil for about 25 to 30 feet per shot.
This is a great way to save the AM ground system, while avoiding backhoe fade. A great idea - until in this case it blew through the station's 200-pair buried phone cable.
Like any good contractor, the crew had made the necessary calls and received a markout prior to digging. They had been told the area was clear.
(click thumbnail)Fig. 2: A bright light can help you discover pending failures like this overheated terminal.
Luckily Ben's STL is an aerial fiber to a T-1. It took Verizon about eight hours to respond and splice the cable. Ben writes that it all made for a fun night. The markout guys came back and confirmed they had been wrong with the first markout.
Thanks for the caution, Ben.
Ben's experience teaches several lessons.
First, make sure you contact Miss Utility or her cousin before any excavation work begins. If the diggers mess up, it's not your fault. If you can't meet the markout folks, verify that the painted marks on the ground indicate they visited your site.
Bring your digital camera and snap pictures showing where the cables are buried. Print them out and file them at the transmitter site. The information could be invaluable in the future, especially if the markout people "miss" a cable.
Finally, with all the changing of ownership that's occurred over the last few years, take some time to sit down with your business manager and see just what bills the station thinks it is paying for the transmitter site.
I've talked about the importance of phone audits, which ensure that you're not paying for a remote line that was disconnected 10 years ago. The same is true for utilities. You may be paying for water service that was shut off because the billing office never got a disconnect order.
Do you have empty nitrogen cylinders that you are "renting" each month, even though they've long been empty? Even unused septic systems that are still being pumped on a quarterly basis can be identified. The list goes on and on.
Perhaps one of the funniest is a transaction in which two broadcasters swapped transmitter sites. Years later, an investigative engineer later discovered that the new owner had continued to pay the property tax on the site it sold.
Find such discrepancies and you'll look great. For once you're viewed as saving money, not simply spending it.
Discuss this work and its compensation with your GM before you start. This is "above and beyond" your routine job duties; because you will investigate the billing on your own time, at home, it is not unreasonable to ask for 10 percent of the savings as compensation.
Remind your GM that a professional audit company will receive 20 to 30 percent of the refund amount, so you're a bargain at 10 percent. Don't assume you'll be rewarded after the fact; you probably won't be, and that will just make you angry. A frank discussion before you embark on the project will lay the groundwork for what you will do and how you will be compensated. Remind your manager too that he pays nothing unless you discover an overcharge. What's to lose? Overbilling can amount to thousands of dollars, money that will be refunded to the station if discovered.
Follow up the meeting with a written memo or e-mail, summarizing the discussion, so there's no misunderstanding.
Here's a resource if you have a major studio project on the horizon.
CAT-5 and CAT-6 cabling is becoming increasingly common, even with HD installations. Especially in studio applications, one of the challenges of utilizing this technology is accomplishing certification to guarantee that cables and systems are operational to specification. This proof of performance is best done during the installation process. A general rule of thumb: almost half of initial digital system problems are related to cabling. However, if you've shopped for network certification equipment, you may have been put off by the price tag, which can be several thousand dollars.
(click thumbnail)Fig. 3: CAT-5 wiring is becoming the norm.
Web retailer SystemsStore.com has a solution. You can add the Byte Brothers RWC1000K Real World Certifier to your project budget. It is a compact and versatile tool, providing testing and recording of both cable and system performance parameters.
SystemsStore is selling the test package for $525. It's a small price for ensuring integrity in the CAT5/6 world. The kit includes both main and remote units, an instructional DVD, batteries, a padded zippered case and even "Passed" Certification Stickers for placement on tested cables.
The RWC operates in two modes. The first, Level 1, consists of a series of projected performance tests that include Cable Length, Opens, Shorts, Split Pairs, & Wire Map, plus Crosstalk and Propagation Delay, to name a few.
Ssetup and test parameters are displayed on a built-in LCD display with navigation controls to scroll through the numerous functions. The unit will hold in memory the results of 250 individual tests, which can later be exported to Excel and printed out with graphs documenting the performance of each and/or selected cables.
The Level 2 or confirmed performance testing allows the RWC to be inserted in the circuit under test. This allows total system testing, including not only the operability and attenuation of the cables, but the throughput (both advertised and negotiated port speeds) and data signal strength of hubs, switches, routers, PCs, etc., as well.
The RWC is similar to a high-speed time domain reflectometer that you may have seen used to verify RF transmission line performance. The RWC has 1 nanosecond resolution.
If you head to www.systemsstore.com , click on the Byte Brothers RWC1000K Real World Certifier. There you can get more information, as well as download the tech manual, a neat feature.
Here, Hold This Light Bulb
Scott Dennis runs InfoTech Alaska in Anchorage. He tells about a studio technician who was training in RF. One day, visiting a transmitter site, the tech started to walk inside the fence of the 10 kW tower. Scott stopped him when the tech was about two feet from the tower.