Wanted: Info on E.F. Johnson Parts

by John Bisset

Radio World Editor Paul McLane and I both enjoy the comments from readers who have discovered our archived Workbench columns. Mark Goff spent an afternoon recently scrolling through the past. He calls it "wonderful stuff."

Thanks to each of you who have contributed over the years. Consider this as your way of giving back to the industry, helping others. You'll never know how many engineers your tips and suggestions have aided.

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Mark Goff is market chief for Eagle Communications. He has just taken over a three-tower DA in central Kansas. Performing an assessment of the array, he discovered a melted roller contact on an old E.F. Johnson variable inductor.

Mark is trying to locate documentation on the components in the phasor and writes that some items date to 1947. Sounds like AM, doesn't it?

He asked for a cross reference for the part or model number for this original coil. I suggested he contact Tom King's crew down at Kintronic Labs in Bristol, Tenn. ( www.kintronic.com ). In addition to phasors, AM diplexers and coupling networks, Kintronic offers a lot of replacement parts, especially for the old E.F. Johnson contactors.

There may be other sources. Readers, do you have ideas? Tell me about them and I'll share.

Mark Goff can be reached at mark.goff@eagleradio.net.

Fig. 1: A magnetic switch can alarm your transmitter door.	Fig. 2: You can tie your site's door to the remote control status.

Steve Ordinetz is chief for WOTX(FM) in Concord, N.H. Fig. 1 shows the simple magnetic switch that serves as a backup alarm to his transmitter site intrusion system.

In the Dec. 29 column I told you about Entercom Scranton's Lamar Smith, who tied this type of switch into his remote control. Steve had done the same thing. Fig. 2 shows the status alarm triggered when the door is open.

Security systems don't have to be elaborate. Sometimes simple is better.

. . .

George Katzenberger mentioned our recent "Scrubbing Bubbles" tip to a beekeeper friend, who offered his own tip for dispatching a swarm of bees after a hive falls off of a truck or - as happened to him - a car knocks over a hollow tree full of bees. The first responders needed him to get rid of the bees so they could get about their work.

The beekeeper's method is to mix one cup of liquid dishwashing detergent in a gallon of water and put it a hand-pump garden sprayer. He uses that to spray the bees. He says they will drop like they were shot.

The method is non-toxic, unlike most insecticides. This a more cost-effective solution (no pun intended) than aerosol cans if a large number of the pesky stingers need to be dealt with.

Thanks, George, for the recipe - a low-cost one, at that. Katzenberger can be reached at gkatzenberger11@earthlink.net.

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Dick McGraw is CEO of the McGraw-Elliott Media Group. He writes with an inquiry for readers:

Is there currently a portable FM receiver that is fairly immune to close-range Marti 161 MHz interference? Dick and his staff like to monitor off the air when doing remotes and feed the station into their PA system at the events.

For years Dick had been using a late-1960s Sony AM/FM/ SW receiver that had no problems at all. but over the years this old friend eventually disintegrated.

Dick has tried respectable brands with unsatisfactory results. He adds that, in his experience, the GE SuperRadio, great for audio, is one of the worst for rejecting Marti blanketing interference.

Readers, have you success stories? What can you recommend?

Dick adds that he's learned many wonderful tips from Workbench. Every now and then, he'll see a story that makes him think, "Gee, I thought I was the only one that had that problem."

Reach him at megdick@verizon.net.

Fig. 3: Snowed in at the transmitter? Here's one way to pass the time.

Wondering what to do with all those RF adapters rolling around in your toolbox? Fig. 3 offers an idea, shared by Fee Lee, who saw it online.

Fee's engineering career runs back to the days of Mutual Broadcasting. He's held a number of engineering positions in the Washington, D.C., market, and is the chairman of SBE Chapter 37.

He's always on the lookout for engineering-oriented devices with a twist. Last year, Fee found a neat little LED key chain that the chapter gave away to members at its Christmas party. This year, he shares a link to an engineer's chess set, which subsequently also enjoyed coverage on RW Online. You can see it in Fig. 3. For more pix, go to www.leapsecond.com /pages/chess.

The leapsecond.com home page, by the way, has some interesting clock and timing information. It's one man's quest for the most accurate clock.

Fee Lee can be reached at feehlee@fcc.net (which is a cool Internet provider for someone in broadcasting, too).

. . .

Randy Murphy handles console, furniture and router sales for Wheatstone Corp. ( www.wheatstone.com ) and is former manager of the Harris Broadcast Center. Randy is known for the service he offers customers of Wheatstone products. This suggestion is a case in point.

Randy found a new way to hide cables without having to fish them through a wall. WireTracks CM kits turn crown molding into a removable wiring channel that you can use to hide low voltage or electrical cables (check your local codes).

They were designed for consumer jobs and can be used to get wiring from the front of a home theater to the back. In commercial applications, the kits can be installed throughout a building to let you run wiring between any two points linked by connected walls. And because crown molding is installed above doorframes, it is easy to get uninterrupted coverage of an entire floor.

Find out more by visiting www.wiretracks.com/prod-cm.htm l. Murphy can be reached via e-mail to randy@wheatstone.com.

John Bisset has worked as a chief engineer and contract engineer for more than 30 years. He is the northeast regional sales manager for Dielectric Communications. Reach him at (571) 217-9386 or john.bisset@dielectric.spx.com.

Submissions for this column are encouraged, and qualify for SBE recertification credit.