Somebody working to preserve a record of past work:
Some of these have familiar looking cabinets and tube arrangements. They all look like classics to me and it is good that they are being saved. I noticed at the end of the video there is a Harris MW10A. As for the RCA Ampliphase transmitters; I maintained a BTA5J in Harrisburg PA on 580 KHz. It was reliable enough, but I could never keep it sounding good for more than a couple of days.
In any case, a worthwhile effort. More information at: AWA Transmitters.
Much ink has been spilled on the aging Broadcast Engineer. While it is generally true, many of the old RF engineers are getting older, there are some younger guys and girls entering into the broadcast technical field. While this is a good development, I look on with a bit of disappointment and a jaundiced eye. The newer broadcast engineers have fewer mentors around as there are fewer broadcast engineers. In addition to that, those broadcast engineers that are still at it are likely very busy trying to fill all the rolls they have been assigned. I have also noted a certain reluctance to impart information to the newer engineers. Perhaps this is some sort of subconscious preservation instinct. Thus, when a young guy that works with us admitted that he didn’t know that much about RF, I was not surprised.
I remember my first mentors in the broadcast engineering field. They were mostly older, near retirement and wanting to pass on their knowledge to the next generation. Several times, Don Porter would sit down at the work bench and draw out some basic schematic diagram on a broken piece of gear and let me try to fix it. It took time and patience because I know I asked many silly questions and made many silly mistakes. Sometimes he would chastise me and sometimes he would laugh and say “I did the same thing once,” which would lead to an interesting story.
Most of the younger people entering the broadcast engineering field (by younger, I mean less than thirty), have some type of computer background. Since there are numerous computers in the studio fulfilling many different roles, having a technical computer person on staff is a good thing. However, those people are often tasked with going to the transmitter site to do maintenance and trouble shooting. That can lead to a dangerous situation. Transmitter sites are and should remain the domain of well trained engineers. Those that know the operating characteristics of a tube transmitter, if there is one present. Those that know the basic principals behind and automatic transfer switch, if there is one present. The real danger of an untrained person at a transmitter site is they don’t know what they don’t know.
Then there are trouble shooting skills, which are only developed with time and experience. It takes experience to recognize that a tower crew has applied the wrong type of connector to an STL transmission line. It takes experience to recognize the failure mode of a Harris transmitter. It takes experience to know when a situation is too dangerous to proceed and wait for help. Formal education is very important, but nothing can replace the education received on the job. The field of broadcast engineering is so diverse and complex that it would be nearly impossible to learn everything in a classroom.
To be a well rounded Broadcast Engineer, one has to have knowledge in many areas:
Basic electronics and electricity: Being able to read schematic diagrams, know what the components do and trace out signal paths. Understanding basic RF amplification by solid state and tube devices, understanding TTL logic, data buses, power supplies, etc
Radio Frequency Principles: Understanding the relationship between frequency and wavelength, antenna theory, antenna operation (MF, VHF, UHF), the relationship between power density and log functions, transmission line theory, propagation types and free space loss.
Audio engineering: Best practices for analog and digital audio wiring, microphones, processing basic studio acoustics and sound, audio levels, analog and digital playback systems and recording.
Emergency Power: Basic functions and repairs for UPS, generators and transfer switches.
HVAC: Basic HVAC principals and operations.
Maintenance: How to maintain the facilities broadcast and broadcast related equipment.
FCC regulations: Part 11, 15, 17, 73, 74, 101 and other FCC regulations pertaining to any broadcast operation.
Other regulations: OHSA, NEC, fire code, ADA, local zoning, etc
And that is simplified list. Many Broadcast Engineers will gravitate toward one or two of the larger categories listed above, e.g. either Computers or RF. Most will know something about both.
The SBE offers several on line courses and webinars with there Education Program.
In addition, many equipment manufactures offer courses, technical publications and white papers:
This is just a brief list, I am sure there are many others available on the internet.
Of course, nothing beats mentoring. Taking an inexperienced, willing to learn person aside and showing them some of the things not taught in school or written in a manual is a rewarding experience. There are still those that get bitten by the radio bug and are worth the effort to bring along.
I found this small, yet very important detail on a DB-37 connector attached to the back of a Nautel V-1 transmitter:
DB-37 connector for Nautel V-1 transmitter
The black wire is the ground wire and the orange wire is the remote RF off command. A closer view:
DB 37 connector from Nautel V-1 transmitter
The transmitter had been shutting down unexpectedly since it was installed. When these shutdowns occurred, there was no overload, no fault, no power interruption or other indication of a problem. When the RF on command was issued, the transmitter would turn back on and run with normal readings until it shut down again. It was a bit of a mystery; the transmitter was removed from its mountain top home and hauled back to the shop to be repaired. It was connected to all sorts of test equipment and studied intently for many days. Still, the problem could not be replicated in the shop.
Then the transmitter was hauled back to its mountain top transmitter site and re-installed. It ran well for about a month and then started going off again. This time somebody looked at the event log and noticed that a “Remote RF off command” was being issued at the same time the transmitter would shut down. Ahhh, the missing bit of critical data. That prompted me to take apart the DB-37 connector used for the remote control interface. The problem was obvious as soon as I removed the hood.
Sometimes the most valuable piece of test gear is the venerable Mk I, Mod 0, EYEBALL.
I unsoldered the ground lead and put some heat shrink over the connection to the DB-37. Hopefully, that will take care of it.
We fight for every scrap we can get. Sometimes it is not a fair fight. Sometimes the most frustrating thing can be the suits in the corner office. We eat, drink and sleep RF. I have transmitter dirt permanently embedding in my skin. If a thunderstorm passes by, I get my shoes on. Last time I was home during a blizzard, I was in high school, and believe me, that was a long time ago. I’ve been hot, cold, soaking wet, dirty, dusty, hungry and dehydrated all in the same day. Those days can be 8-36 hours long or longer. 240 volts AC is low voltage. Arcs and sparks are a diagnostic tool.
I have clip leaded things, used non-standard parts to get a transmitter back on the air, employed fans on power supplies, filed, cut, bent, tightened, burnished relay contacts, put plate transformers up on a block of wood and crossed my fingers while turned the plate supply on.
My DVM looks like this:
Fluke 111 DVM
But the best part is, when I walk into a radio station studio, the DJ says “THANK GOD YOU ARE HERE!” I don’t drive a fancy car or wear a fancy suit, but the respect I get is there, even with the young too cool for school guys on the CHR station.
I am a broadcast engineer and I am here to fix your shit.
