BOSTON: Paul Shulins, Greater Media Boston’s director of technical operations, uses two uninterruptible power supplies in each of his transmitter site equipment racks. The supplies power separate AC strips found on each side (left and right) inside the rack.

Paul has labeled the two uninterruptible supplies “red” and “green.” Simple enough, but here’s a slick idea, seen in Fig. 2. He uses twist-lock plugs to feed the input and output of each UPS. The disconnect/bypass panel, shown in Fig. 3, also is color-coded for easy identification.

Fig. 2: Paul Shulins color-codes the plugs for dual-UPS applications.

Fig. 3:Use the same color coding for the disconnect/bypass panel.

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Stephen Lockwood of Seattle consulting firm Hatfield & Dawson has worked with the Society of Broadcast Engineers to set up the SBE RF Safety course, which is the topic of a webinar on May 24. It is aimed at radio and television engineers as well as ENG and SNG maintenance personnel.

RF safety expert Richard Strickland, whom readers may remember from his days at the test instrumentation firm Narda, will present the webinar. Strickland founded RF Safety Solutions in 2001 and has authored numerous RF safety-related articles in Radio World.

For links to the course and to past RF safety stories, visit radioworld.com/May-09-2012.

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Broadcast engineer Paul Sagi writes from Kuala Lumpur about a simple way to hold onto those little plastic wire jumpers found on circuit boards.

Fig. 1: Store unused plastic contact jumpers by parking them on unused pins.

These jumpers usually permit two of three in-line pins to be shorted for various functions. The problem arises when the jumpers are not needed immediately. They are so small that they will get lost in a tool bag or parts drawer.

Because you may need your jumpers someday, park ’em. Place each jumper on one of the end pins of the in-line strip, so it contacts just that one pin. This way, the jumper can be found when you need it, yet it’s making no connection.

Paul has done just this with the circuit pictured in Fig. 1. Look at J-1, labeled OP/CL – HWS, right under the fourth blue potentiometer at the top of the board. Great idea, Paul.

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Mike Fast, who does project work and is retired director of engineering at WCBM(AM), brought to my attention a new book on the history of Bell Labs by Jon Gertner. “The Idea Factory: Bell Labs and the Great Age of American Innovation” tells a fascinating story about the organization during its heyday from the 1920s to the 1980s. In its time, Bell Labs was the most productive scientific laboratory in the world, winning seven Nobel Prizes, Gertner writes.

Thanks, Mike, for the review.

Contribute to Workbench. You’ll help your fellow engineers and qualify for SBE recertification credit. Send Workbench tips to johnpbisset@gmail.com. Fax to (603) 472-4944.

Author John Bisset has spent 43 years in the broadcasting industry and is still learning. He is SBE certified and is a past recipient of the SBE’s Educator of the Year Award. He recently joined the FM transmitter company Elenos USA.

-- Radio World