Cyclops Eye Shines Light on Problems

Also, some ideas for Bob Culver’s open neutral problem from January
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Chuck Bullett, CSRE, market engineer for Cumulus stations in San Francisco, writes that he received the coolest catalog in the mail (yes, some companies do still send out catalogs).

Duluth Trading Co. sells work wear and tools. Apparently one of their biggest sellers is a “long tail” T-shirt to cover up plumber’s crack. The cover graphic is a hoot, but the supplier also offers a host of tools and gadgets including unusual selections that could find a home at your shop or transmitter.

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Fig. 1: The five-LED light assembly clips on the visor of your hat. For example, for less than 20 bucks you can buy the Cyclops Orion 5 Hat Clip. This is a five-LED light assembly that clips on the visor of any hat, helping to illuminate the subject. It’s available from other online vendors too. (Our editor Paul McLane recalls a previous tip we published about a hat with LEDs built right into the front of the visor.)

While you’re on the Duluth site, surprise your significant other. The company has both men’s and women’s catalogs. Check out www.duluthtrading.com.

* * *

Bob Culver’s single-phase/neutral issue (see the Jan. 12 column) brought a number of unique solutions.

Scott Johnson, a systems engineer with Wheatstone, suggests replacing the main breaker with one that has a shunt trip on it. Bob could then build a simple circuit with two window comparators ANDed together to monitor the voltages of the two phases. Pass the output through an inverting buffer and let it fire the shunt trip on the breaker.

Scott adds that there also industrial phase monitors (snaptrack, relay rack or octal form factor) that will provide a voltage or closure when voltage goes outside limits, and these could similarly trigger the shunt-trippable breaker. These aren’t all that expensive and may solve the problem.

* * *

Jim Schultz is a master electrician and owner of Schultz Communications. Jim has run across this open neutral problem and agrees the results can be devastating.

He is based in Connecticut, where licensed electricians are allowed to do “live cut and tap” service changes with a written agreement with Connecticut Light & Power. This allows them to remove old services and reconnect to the power company’s service lateral.

Every time Jim does one of these service changes, he makes sure that the neutral leg is a few inches longer than the phase conductors. Then if a tree limb comes down on the drop, the last connection that is broken is the neutral.

Also, if the weatherhead is installed with a small screw rather than a large one, it will pull free and give a few more feet of slack before the wires are broken. This often is enough slack to prevent breakage of the wires and the resulting service interruption.

Jim also has seen the jacket melted off the cable TV drop, as the shield on the coax has acted as the power neutral conductor when the aluminum conductor, steel-reinforced (ACSR) messenger cable has failed.

Several T-shirts and maybe a case of beer on a hot summer day, strategically gifted to the line foreman (not the power company engineering folks!) may win you a favor from the power company. Just ask them to shorten up the phase conductors at the service drip loop.

* * *

Keith Trantow is president of Rawhide Communications in Tucson, Ariz. He is one of the many readers who scour each issue of RW cover to cover.

With regard to our Jan. 12 suggestion about old cases protecting fragile gear, Keith finds that padded laptop computer cases can be used to carry various items like test gear or remote equipment safely. They can be found inexpensively and usually are rugged enough to give years of service.

* * *

Buc Fitch is one of the few guys I know who still has time for involved equipment construction projects. He’s shared many in Workbench over the years. As you probably know, Buc likes to add life to worn-out gear. Figs. 2 and 3 reflect his latest efforts.

The old RCA FM exciter had modular “drawers” that fit into the main chassis. Fig. 2 will look familiar to veteran engineers. Buc constructed a mono/composite input assembly, seen in Fig. 3.

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Fig. 2: The old RCA drawer slides into the chassis.
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Fig. 3: Adding the mono/composite input circuitry completed the project.

But he laments that the project took over 40 hours of design, layout, construction and test time. At his rates, he says, “I could have bought a new exciter!”

John Bisset marked his 40th year in radio in broadcasting recently. He works for Tieline Technology and is a past recipient of the SBE’s Educator of the Year Award. Reach him at johnpbisset@gmail.com or (603) 472-5282. 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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