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Annotate Manuals, Supplement Memory

Strobe lights can help you detect on-air silence, too

Reader Ihor Slabicky writes about a recent article by Mark Persons in Radio World (“Bench Techniques and Tools of the Trade,” Dec. 16, 2015) that mentions marking up circuit diagrams in equipment manuals when you make changes, updates or upgrades to your gear.

It’s a great idea. But there’s another good reason to mark up your manuals. This is a tip that may save you a lot of frustration in the future: Annotate your manual with instructions for how to get into and out of the equipment. Knowing how to open and close that device can save time.

For example, which screws do you unscrew to remove the cover? Sometimes “extra” screws hold subassemblies in place and should not be removed. The notes could also include whether you’ll need any specialized tools. Sometimes the sequence in which screws or bolts should be removed or tightened is important.

Notes and documentation of steps in the manual can save you time and effort when you have to get inside that equipment and can’t recall how you did it last time. Given the reliability of broadcast equipment, it may have been a year ago or longer since the equipment was serviced.

Notes also help with mundane tasks. For example, twice a year Ihor adjusts several compression hose clamps. The process sounds simple, until you consider that the adjustment can be made using either a screwdriver or a socket wrench. The questions begin with which screwdriver — flat blade or Phillips? — and which size? What size socket? It turns out that, for Ihor’s task, an 8 mm socket was ideal, so he added a note in the manual to “use 8 mm socket” next to the diagram showing the clamps.

That little note tells Ihor the right tool to use for the job; the diagram tells him which clamps may need adjustment.

I remember a transmitter driver board that was held in place with a Phillips head bolt. The problem was that a very short or right-angled driver was needed for access. In addition to marking the manual, we kept this special “stubby” screwdriver in the transmitter site desk drawer, along with a label identifying how it was used.

Noting component changes on the schematic, along with factory modifications, is just as important. Years ago, an engineer showed me how he had enlarged and mounted an overall transmitter schematic on the wall, then covered it with a clear Mylar film. Using a grease pencil or Sharpie brand marker, he could add notes to the Mylar without damaging the original schematic.


Fig. 1: Red strobe lights are tied to each studio’s silence sensor. So many facilities are clustered these days, and silence sensors are an absolute must. But a sonic alarm just adds to the off-air confusion, unless you quickly can identify the station in trouble.

Entercom San Francisco Staff Engineer Horace Wong solved the problem for his cluster by adding warning lights.

Horace has the advantage of all studios facing a long hallway. He added red strobe warning lights in the ceiling, outside each studio, as seen in Fig. 1. Since the installation, should the silence sensor trip, staff members just look for the flashing strobe light.


Frank Hertel of Newman-Keys Consulting frequently finds interesting products on the Web. In Frank’s travels, he has noticed a lot of transmitter sites with old rotary telephones still hanging on the wall. Some new phone terminal equipment doesn’t work with rotary dial phones, nor recognize the pulse dial output from some older remote control systems still in use. Only DTMF touch tones are recognized.

RotaTone converts your rotary dial telephone into a touchtone telephone, without adding any buttons. It also gives you the capability to dial and #. With this technology, you can do your phone banking or access voicemail services using your rotary dial phone. You will also now have “last number redial” and you can store seven phone numbers you regularly use.

Head to for more information. In the U.S., to order the module, the URL is


Fig. 2: A compartmentalized plastic case with a lid keeps parts secure. Steve Tuzeneu is a staff engineer at the Bible Broadcasting Network in Charlotte, N.C. Instead of using jars or pill bottles to hold hardware while disassembling equipment, he uses the plastic compartmentalized tray shown in Fig. 2. Before putting the parts in a compartment, Steve adds a slip of paper first. The paper tells him where the screw or parts came from.

An added benefit is that he can close the lid, keeping all the screws and parts from getting knocked off the workbench or mixed up.


We received a comment from Roberta X regarding the Milwaukee inspection tool featured in our Nov. 2 column.

This lighted camera, mounted on the end of a cable umbilical, permits peering into tight spaces. Roberta suggests that a regular smartphone can also be used as an inspection camera for some tight spots. Whether you are using the flashlight app to illuminate your work, or using the camera to peer between circuit boards in a card cage, under computer floors or in dropped ceilings and wiring ducts, a smartphone serves as a “remote eyeball” available in your pocket.

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Author John Bisset has spent 46 years in the broadcasting industry and is still learning. He handles West Coast sales for the Telos Alliance. He is SBE certified and is a past recipient of the SBE’s Educator of the Year Award.