Articles for the Radio Broadcast Industry

Terms of Use & Disclaimer

Back in the 1960s, when I started working in broadcast engineering, a fair amount of attention was paid to the "quality" of work at radio stations.  Quality work was usually done by a full-time engineer at "his" radio station, before the era of the contract engineer. Wires were laced together into bundles. That was before cable ties. Documentation showed where every wire went.  Not all stations were like that. Neatness demonstrated pride, or lack of it, on the part of the person doing the work.  Today I see a mix of bad and good.

Fig. 1: Thumbs down on illegal wiring. Photos by Mark Persons

The thumbs-down example in Fig. 1 shows a 120 VAC electrical cord mixed with low-voltage wiring on an electrical conduit. That is a double no-no! Always keep low-voltage wiring separate from other wiring. A short could develop between cables, putting dangerous 120 VAC on low-voltage wires. The short could come from a lightning strike or accidental abuse.

The National Electrical Code also says you will not lay cable on a suspended ceiling. Firemen need to be able to "blow out" ceiling panels with water to get at a fire above. Cables resting on ceiling tiles may prevent that. You could be involved in a lawsuit.

On the good side, I see computer and audio cables run in an organized fashion with nice, rounded 90-degree corners and no odd-angle shortcuts in most new installations.

I preach and personally like to see a facility maintained and updated to the standards on which it was built.

Minnesota and a few other states require licensing of low-voltage technicians, which includes broadcast engineers. I became a Power Limited Technician and my company was an official electrical contractor. That happened after Minnesota state law was changed to require it; see an article I wrote for Radio World on April 11, 2001 (www.mwpersons.com/articles/3-12-01-licensing.html).

Licensing of that kind is likely coming to a state near you. I mention this because anyone with an electrical license is expected to know and comply with wiring codes. There isn't much room for sloppy work when an electrical inspector visits for another reason and then inspects low voltage cables too.

Fig. 2: Use a good marking pen to label everything.

Take pride in what you do.  One of the things my clients noticed and complimented me on is how clean I left a site. Yes, a broom and dust pan were part of the tool set in my service van. Work was always done on a "time and material" basis, so the client wound up paying for the cleaning, whether he knew it or not.  It is difficult to keep a transmitter site clean if mice get in. Some engineers set traps or ingenious high-frequency sound devices in an attempt to drive mice away. The best answer is a bit more difficult. It involves keeping mice out so they can't get in to mess things up.  I encountered this many times and often used 1/4-inch hardware cloth screen to block openings. Also, space between a door and door threshold can be large enough for mice to enter. The goal is to keep the mice out so they don't get in and chew wires, then stink up the place after they die!

If you pull a tube out of a transmitter, mark the anode with its condition, such as "makes 90 percent power."  Even if you are the only one servicing a transmitter site, these reminders make life a lot easier at 3 a.m. Do not mark on a tube ceramic insulator with a pencil or any other writing instrument. Pencil lead is conductive and can cause an arc-over when the tube is installed.

GROUND-UP
Whenever I built a new station (12 total over the years), I always started with the grounding. Yes, it wasn't as glamorous to onlookers, but it was the "ground up" approach. I've seen installations where grounding was left to the end and then not done at all. Suddenly, lightning took out major components. You don't want egg on your face if someone points that out after a disaster.

File all equipment manuals alphabetically by manufacturer. Keep the manuals in the same building as the equipment. It doesn't make any sense to have documentation at a studio when you are 10 miles away at a transmitter trying to repair something in the middle of the night. Remote control manuals should have penciled-in programming notations so they can be changed to suit a new situation. Again, the books need to be where the equipment is.

Fig. 3: Plastic boxes from electrical tape make excellent hardware holders.

Fig. 4: Cable with alligator clips for shorting an AM tower to ground.

Use small, low, flat containers (Fig. 3), such as from electrical tape, to organize hardware so it doesn't get lost while it is removed temporarily from equipment. This procedure will save a lot of time and trouble when you reassemble it.

Safety first. When workers will be on an AM tower, turn off the transmitter and short the tower to ground. The one in Fig. 4 has #6 copper stranded wire and label so not to be accidentally discarded. A battery jumper cable will do just as well. This is especially important if the tower is a part of an AM directional antenna when other towers in the array are still hot with RF.

Think ahead and do a good clean job. You can then point back and say it was another installation to be proud of. That is one of the things I like about engineering: Anyone can see the result. Even non-engineering types will notice shoddy work and may think less of you for it.

Fellow Radio World contributor Charles "Buc" Fitch says, "A professional does his best work all the time, even if no one is watching, if no one really cares, and even if he really doesn't want to do it."

Making the station the first priority, instead of myself, got the job done right. This attitude kept me employed as a contractor for 35 years. It makes perfect sense.

Mark Persons, W0MH, is a Certified Professional Broadcast Engineer and has more than 40 years� experience. He has written numerous articles for industry publications over the years. His website is www.mwpersons.com.