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WOBC Control Engineer's Handbook
Added to website April 2001


Background: When you show the bottom of your clipboard to the person on the other side of the window, what response should you expect?

Were you aware that classical music has greater variations in loudness than popular music?  Did you know that as a consequence, classical music announcers should be 5 db softer than disk jockeys?

When playing a long symphony from a two-sided LP, can you flip the disk so that there's only ten seconds of "dead air" between the two sides of the record?

Do you know how a "cart machine" works, or how an "interlock" controls the speakers in a studio?

Just check the handbook!

Here are excerpts (sometimes disjointed excerpts) from the half-inch thick manual which I updated in August and September 1968, having become station director of the ten-watt "radio voice of Oberlin College."



Adapted from the WOBC Engineering Handbook,
written largely by Jud Leonard (chief engineer 1965-66)
and Walt Jones (chief engineer 1966-67)

Revisions and new material
by Tom Thomas (station director 1968-69)

Click the gold square to return to this table of contents.


Click a crimson diamond to jump to its section:

Duties & Reponsibilities

Console & Consolette

Speakers & Microphones


Tape Decks

Cart Machines

Emergencies & Troubleshooting

Hand Signals

Sign-Off Continuity

This is intended to familiarize you with the everyday operation of the equipment of WOBC, whether your desire is to be simply an engineer for classical music and news, or to "combo" as engineer and announcer at the same time, as for instance our disk jockeys do.  The members of the "executive board" will be willing, occasionally even eager to remind you of particular points.

WOBC is rebuilding.  In the past two years we have replaced turntables, all our tape recorders, and our speaker and intercom system, and within another year we hope to replace our aging control boards.  As you may already know, we call these boards Console and Consolette (or "con" and "cette" for short); they control practically all phases of what goes over the air, if they're working properly.  One of the things you'll learn is the resourcefulness to figure out how to use the boards when they aren't working properly.  Heaven knows our technical staff tries to keep things going.  But if you could see the wiring behind some of those panels, you'd know why the old boards just aren't too reliable.

Perhaps you'd like to see the wiring behind some of those panels.  Come into the goober room any Saturday afternoon.  The chief engineer holds tech parties then.  He'd like to have as many helpers as he could get.  We neither demand nor expect electrical experience on the part of a young innocent.  Most of us knew nothing about electronics when we started the game.


Duties & Responsibilities

Unannounced tardiness or absence alienates one from the affections of all sorts of people, including the engineer with the preceding shift, who cannot leave until someone arrives to relieve him.

The standard ID is "Double-you-oh-bee-see, AM and FM, your station for (music/news/whatever) in Oberlin, Ohio."

If the incident power ("inc") reading is greater than 100%, as occasionally happens, try to estimate its position (e.g., 104%, 110%, not simply 100+).

Times must be recorded accurately within five seconds on the 24-hour system.  If you're confused in the afternoon or evening, just add twelve hours to whatever time it really is.

By a special unwritten agreement with the FCC, WOBC engineers may operate the station equipment even if they do not hold an FCC third-class license.  However, we request all engineers who don't have a license to apply for one; we provide study guides, and once a semester WOBC organizes an expedition to Cleveland, where the test is given.

Like the typeface in a book, the best engineer is the least conspicuous.  A skilled engineer can put such a polish on a program that the listener is aware of nothing but the music and the announcer.

To avoid distractions, a new engineer is encouraged to depopulate the control room and studios, so that he may concentrate on producing a flawless broadcast.

Plan ahead.  If you don't know exactly what you're supposed to do next, or if you don't have a good general idea of what's going to be happening during the coming hour, ask.


Console & Consolette

When a signal from one of our many signal sources is brought onto the board, it is fed to an attenuator.  This is basically a volume control, a big black knob which we call a "pot" (from "potentiometer").  When a pot is on neither "cue" nor "off," it allows a portion of the signal which is being fed into it to continue on to the broadcast switch, which is located just above it.

When the broadcast switch is thrown to the right, the signal being fed to it is connected to the program channel.  Simultaneously, a light goes on (a green light for console, while for cette the switch itself changes color from white to red — it's all done with mirrors).  This light indicates that the interlock has been activated.  Now that may not mean much to you, but the interlock is a very handy gadget which does the following things for the following signal sources:

Microphone -- shuts off all speakers (but not earphones) in the studio in which the microphone is located, and in any adjoining studio if the door between the studios is open, to prevent feedback.  Turns on a red light over all doors leading to those studios to warn people that there's a live mike inside.

Console Turntable — starts the turntable turning when it's turned on, stops it when it's turned off.

Tape Deck (Mags One and Two) — starts the tape moving when it's turned on, stops it when it's turned off.

Cartridge Machine (Mags Three and Four) — starts the tape moving when it's turned on, does not stop it when it's turned off.

Cette Turntable, Auxiliary — doesn't do a thing as far as we know.

When using any input, turn on the broadcast switch first, then turn the pot up from "off" to the proper level.  When finished, fade down the pot, then turn off the switch.  In this way, any clicks introduced by interlocks going on and off are suppressed by the pot.

Too low a level causes weak signal strength and a poor signal-to-noise ratio — and dissatisfied listeners.  Too high a level causes overmodulation (which is illegal) and distortion — and dissatisfied listeners.  Inconsistent levels cause knob twisting at the other end, and, depending on which knob is being twisted, either dissatisfied listeners or no listeners at all.

For speech, peak readings of the VU meters should lie between -7 and -5 decibels for classical-music programs and other programs in "classical-music hours."  However, dj's should let their voices peak around -2 to 0 db.  For either type of music, peaks should not exceed 0 db.

Here is where you run headlong into your first major conflict between technicians and classical music lovers.  Technicians will tell you that too low a level causes weak signal strength and excessively low signal-to-noise ratios.  Classical music lovers will reply that Brahms wrote with a wide dynamic range and it's a crime to arrange it otherwise.  Then they complain about the background noise during the soft passages.  Sigh . . . .

The best answer we've come up with so far is this:  Never let peaks exceed zero level.  In passages with fairly rapid or sudden changes in dynamic level, leave the pot alone, letting the level fall as much as it will.  For long soft passages, however, ease the pot up somewhat if you're confident the soft passage will last several minutes or more.

In any case, however, the VU meters must be your reference for volume settings.  They are far more trustworthy than your ears, except for matters of relative volume (announcer as compared to music, for instance).


Speakers & Microphones

The basic control unit for the speaker-intercom system is a little box called Helpful Hiram.  One is located in each studio and office.  Hiram has a rotary selector switch to determine which channel comes over each speaker, a volume knob for each speaker, a plug-in jack for earphones with knobs to control left and right volume, a cough switch which disconnects all microphones in that studio as long as it's held down, a carbon microphone for the intercom system, and a set of push-to-talk buttons which enable you to call the various studios on the intercom.

Don't turn the speaker volume controls down so low that you won't be able to hear a call on the intercom.  If you want your speakers off, do it by changing the setting of the selector switch, not by turning down the volume all the way.

Don't abuse the intercom.  If someone is trying to do a show, don't bother him with unnecessary and distracting electronic comments.  Even if his microphone is on and his speakers therefore off, he can hear you on his earphones.  For the same reason, use the "all-call" button (which sends your voice to every studio at once) only with discretion.  Newcasters get flustered if in the middle of giving the stock-market report they hear "Robertson, get in here!" on their earphones.

Incidentally, we suggest that new announcers practice off the air with using earphones before trying to use them on the air.  Hearing one's own voice in one's ears is distracting to some people at first.

An announcer should face the microphone when talking, with his mouth 10 to 24 inches from it.  If he gets too close, blasts of breath make irritating rattling noises on the air, but if he's too far away, the direct sound of his voice begins to get buried in the vague echoes of it coming from the various walls around him.

Note that besides switching the signal sources, the non-normal switch rearranges the interlock.  Thus, throwing the Mike 2 switch from Normal to Non-Normal means not only that the Mike 2 pot gets the signal from the control-room connector rather than the signal from the Studio A connector, but also that the Mike 2 broadcast switch cuts off the control room speakers instead of the Studio A speakers.  Aren't you proud?



When you want to cue a record on one of the console turntables, follow these steps:

(1)  Carefully remove the record from its jacket and from the inner protective sleeve.

(2)  Handling the record only by its outer edge and by the label in the center, carefully place it on the turntable.

(3)  Flip up the mercury switch; while the record turns, clean its surface with the preener.  (Read the instructions for using this black plush gadget on the plastic tube that contains it.  It works wonders when it's damp, but it does no good at all if the wick is dry.  It takes only a couple of minutes to walk down to the men's room at the east end of the Wilder third floor and wet the wick.  Help preserve our classical records!)

(4)  Flip down the switch to stop the turntable.  Carefully place the tone arm so that the needle is in approximately the right position on the record.

(5)  Turn the pot for the turntable you're using to the "cue" position.

(6)  Holding the turntable still with one hand to avoid stretching the belt, spin the record with your other hand (don't touch the grooves) until you hear noise from the cue speaker.

(7)  Spin the disc back and forth until you know just where the music begins; then, still holding the turntable fixed with your other hand, back up the disc by at least a full turn.  This backing up is to give the turntable time to reach full speed before the music starts.

(8)  Once the record is cued, it may be started by turning on the broadcast switch for that turntable and fading up the pot.  With a full turn backcueing, the music should start two or three seconds after you throw the switch.

If you have a record for which the second side is supposed to follow the first with no announcements in between, you'll have to execute what's called a "record flip."  With practice, you can get this process mastered so that there's only about ten seconds of silence, or "dead air," between the two sides of the record.

The two cette turntables are fast-starting rim-driven units.  There are several advantages to a rim-drive system, particularly in pop music shows, where a two- or three-second pause before every record would detract from the fast-moving, lively spirit of a good show.  But when you're done with the turntables in cette, leave them out of gear, or we'll get flat spots on our idler wheels.


Tape Decks

Our two stereo Ampex tape decks are called Mag One and Mag Two.  The names date from the early days of WOBC, when all our tape decks were Magnecords.  Our machines are half-track stereo, set up to play back only monaurally since we don't broadcast in stereo.

Open the black plastic head cover and thread the tape exactly as shown in this diagram.  If you thread the tape on the wrong side of any of the little pins and rollers, it won't play properly.

When you're ready to play the tape on the air, turn on the appropriate broadcast switch and quickly fade up the pot.  The tape starts to move automatically and keeps running as long as the broadcast switch is on.  The interlock, which is what tells the tape to move, also disables the pushbuttons on the mag, so you can't stop the tape by accidentally hitting "S" or "R."

If a tape breaks, there is a splicing block located under each mag, and a dispenser of splicing tape and a razor blade should be on the counter near console Turntable 1.

If someone wants you to play a tape that was recorded on someone's personal tape recorder, chances are you'll run into trouble.  Most personal machines these days are quarter-track, so with our half-track playback heads you're likely to get two of those four tracks at once.  Another problem is that many home recordings are at 3-3/4 ips, a speed which our machines won't play back.  A method of handling both problems is to ask the person who recorded the tape to bring his own tape recorder up to the studios.

Theme tapes are seven 7" reels of tape, one for each day in the week (the first half of Sunday is on the Saturday reel, however); they are stored in the slots under the console counter near Turntable 1.  The average control engineer will play these tapes much more frequently than any others.  On each reel, the various themes are separated by leader tape.

Consult the list, cue up the next theme that's supposed to be played, and then do the following:

(A)  If the list does not contain an entry in the column headed "WHEN START MAG," you will put the tape on the air at the approximate time which is listed in parentheses in the column headed "WHEN PUT TAPE ON AIR."  Usually the theme will be the opening theme for some program.  Once it's playing, watch for a signal from the announcer.  When he's ready, (1) turn on his mike, (2) fade up the pot for his mike, (3) partially fade down the pot for the mag so that the music is about half as loud as it was, and (4) nod to the announcer to begin talking.  A good engineer can perform all four of these steps simultaneously, using one hand for (1) and (2) and the other hand for (3).

(B) If the list does contain an entry in the column headed "WHEN START MAG," you'll start the tape at exactly the time listed but you probably won't put it on the air until later.  The tape contains the closing theme for some program, cleverly arranged so that the theme ends at the exact time the program is supposed to end — if you start the tape at the right time.

In some cases the leader tape used is a short piece of blue tape which will pass through the mag in only two seconds.  This is used for those occasions when it may be desired to let the theme tape keep right on running from the end of one theme to the beginning of the next without pause.

Two special problems may arise with closing themes.  If the program is behind schedule and is still going on thirty seconds before the theme tape is going to run out, and you still haven't had a chance to get the theme tape on the air, stop the theme tape!

The other problem comes about if the program ends early.  Don't start the next program early!  A good source of filler music is the "guitar tape," thirty minutes of classical-guitar music on a reel in the same slots as the theme tapes.  Or, if you need only about a minute of filler, you may be able to dig up a public-service announcement, either a PLUG or a SERVE spot.

In other words, it's okay to delay the closing theme and end a program late if necessary, although we don't like to do it; but don't begin a program before it's supposed to begin, or that program's loyal listeners may miss the first few minutes and be displeased with us.


Cart Machines

We have two new stereo Gates cartridge tape machines, installed in the summer of 1968.  The one located in the control room under Mags One and Two is called Mag Three; it can record as well as play back, and it has special splitcasting capabilities.

Cartridge machines use only one reel, safely packed away in a plastic box.  An endless loop of tape feeds from the inside of the reel and winds back onto the outside; look at one of our cartridges, or "carts," to see how it's done.

Because of the one-reel design, carts are compact and easy to handle, but they have an even greater advantages:  they cue themselves.  In addition to the two ordinary sound tracks on the tape, which carry the "production" you want recorded, there is a third one, a "cue track," on which a 1000-hertz beep is automatically recorded when you start recording the production.

We are a non-commercial FM station, but we do make money from playing commercials on AM.  To fill time on FM while the commercials are going out over AM, we use public-service announcements.  The FM announcement and the AM commercial, each timed to sixty seconds, are recorded side-by-side on a single cart so that they can be played simultaneously.  Therefore, each control board is set up so that the left channel of Mag Three is fed to FM, and the right channel of Mag Three is fed to AM.

To play a cart, just insert it into the right-hand side of the slot in Mag Three or Mag Four.  Notice that the orange STOP light comes on; this means go ahead.  (Logical, isn't it?)  When you're ready to play the cart, fade up the pot and then turn on the broadcast switch (note the unusual order of events).  The music or whatever should begin almost immediately after you turn on the broadcast switch.  When it stops, fade down the pot and turn off the broadcast switch.  The cart will continue running silently until it gets back to the cue tone; then it will stop itself and may be removed from the mag.

Warning:  Never press the orange REC SET button on Mag Three unless you know what you're doing (see the Special Procedures Manual for how to record carts).  If this button is glowing when you turn on the Mag Three broadcast switch, terrible things may happen to whatever's recorded on the cartridge, and the wrath of many will be brought upon your head.


Emergencies & Troubleshooting

If the teletype bell rings ten times, check the teletype to see what it's printing out.  If it says something like, "A NATIONWIDE ALERT HAS BEEN DECLARED.  ALL NORMAL BROADCASTING WILL CEASE IMMEDIATELY," open the brown envelope on the newsroom bulletin board and compare the word lists to confirm that the alert is genuine.  Then sign off by reading the following paragraph, saying "I repeat" between the first and second readings:

This station has interrupted its regular program at the request of the United States Government to participate in the Emergency Broadcast System.  During this period, this station will go off the air, but some radio stations will remain on the air broadcasting news and official information for their areas.  You should now tune your radio until you hear a radio station which is broadcasting news and information for your area.

TROUBLESHOOTING:  No Lights on Desired Control Board

(1)  Check that the "WOBC Power" switch on Rack 3 is turned on.

(2)  Check for a neon light above one of the three fuses to the right of the Emergency Fuses switch, also on Rack 3.  If a light is glowing, turn off the "WOBC Power" switch, turn the Emergency Fuses switch to one of the other two positions, and turn the "WOBC Power" switch back on.  If another of the neon lights glows, find the trouble before trying again.  You have only three fuses.

(3)  If no neon lights are glowing, check that the big three-pin twist-lock plug behind Rack 3 is plugged in, and that all the circuit breakers in the wall box in the hall opposite the goober-room door are on.  Check particularly circuit breakers #23, 25, 27, and 29.

(4)  Scream.

(5)  If suggested solution (2), (3), or (4) successfully fixed the trouble, leave a note for the chief engineer.


Hand Signals

#1  GO AHEAD — Point at the other person, or look at him and nod.  This is the universal "go" signal and is usually also used in place of signals #2 through #9, provided that you're sure that the other person knows exactly what it is that you want him to go ahead with.

This is a frame from a very brief film clip included in the 2011 Oberlin College holiday video.  It seems to be 16mm footage from the spring of 1968, 1969, or 1970.  Following a script, an engineer (possibly Paul Wilczynski) cues Marc Krass to read the introduction for his two guests in Studio A.  There's a similar photo here.

#2  START TALKING — Mimic jaws moving by tapping the tips of your index and middle fingers against the tip of your thumb, held horizontally.

#3   START THE RECORD — Trace a horizontal circle in the air.

#4  START THE TAPE — Trace a vertical circle in the air.

#5  TURN OFF THE RECORD OR TAPE — Make a short slashing motion.

#6  TURN ON MY MIKE — Point at it.

#7  TURN OFF MY MIKE — "Cut your throat" with your index finger.

#8  START THE THEME MUSIC — Make a T with your two hands.

#9  PLAY A SPOT — Touch your nose, then give signal #1.

#10  ATTENTION — Wave both arms above your head.  Or tap the proper intercom button three times.

#11  GET READY — Raise your hand.

#12  STOP — Display your palm and waggle it back and forth.  This signal followed by #1 means "start over."

#13  GIVE AN I.D. — Hold up the program-log clipboard so that the other person can see the big "ID" on the backside of it.

Note:  Announcers must not consider the cutoff of their speakers and the flashing red light in Studios A and C as a substitute for signal #2.  The light is a warning that a mike may be on, not a sure indication that one in fact is.  (For instance, the pot may still be turned all the way down.)  The engineer must always give the announcer a clear hand signal to start talking.


Sign-Off Continuity

At this time, radio station WOBC concludes another (morning/day) of broadcasting.

We transmit at 590 kilohertz short-range AM in certain dormitories on the campus of Oberlin College, and at 88.7 megahertz non-commercial educational FM by authority of the Federal Communications Commission.

WOBC is owned and operated by the Oberlin College Student Network Incorporated, with studios and offices in Wilder Hall, the Oberlin College student union building, in Oberlin, Ohio.  All programs broadcast by WOBC are listed in our program guide, a bi-weekly publication which is available to you free on request.

We invite our listeners to join us again at (time) (this afternoon/tomorrow morning) when WOBC will present (name of program).  Until then, this is (your name) speaking for the entire staff of WOBC, bidding you a very pleasant good (morning/evening).



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