Calling the transmitter

May 15, 2013 4:49 AM

I briefly worked an early-morning shift at a college radio station in the late 90s. One of the first things I had to do was call a number, listen to an automated voice read out a series of numbers (which I vaguely remember as being related in some way to the transmitter), and write them down into a logbook. Three-part question: what was I doing, is this still done today, and where, if anywhere, can I hear that voice again?
posted by Mothra Pisces to Technology (9 answers total)

Best answer: Radio stations are required by the FCC to monitor their transmitter's output as to output power and what frequency it's broadcasting on, etc. This sounds like a way for a non-technical person to check that square. HOPEFULLY a broadcast engineer was glancing at the numbers every now and then for signs of trouble.

I would expect it's being sent to engineering departments via some Internet protocol today. Your college station of the late 90s was probably using technology that was 10 years off the curve then...
posted by randomkeystrike at 5:08 AM on May 15, 2013

Best answer: As of 2009 my college radio station was still doing this in exactly the same way. randomkeystrike is correct as to why it's done. I would expand that we were required to maintain and hold onto these notes in case we were ever audited by the FCC.
posted by telegraph at 5:11 AM on May 15, 2013 [1 favorite]

Best answer: As to your last question, google 80s voice synthesizers :-) they were in use on amateur radio repeaters. I think they were done by having real humans read letters, numbers, and common words and phonetics and a processor would put them together in strings. Very crude, no attempt at natural inflection in the early days.

An amateur radio repeater I knew in those days had some fun with it:

Male voice: "High K this is Charlie. Watts the time?

Female voice: The time is: (announced time).
posted by randomkeystrike at 5:12 AM on May 15, 2013

Simple formant synthesizers were also very common ways to do speech synthesis in the 80s. (Essentially they contain an extremely simplified analogue-electronic or possibly digital model of the human vocal tract, and a list of how to vary its parameters over time to produce different phonemes or words). They were good at being intelligible, but not very good at sounding like a live human— it turns out these are different problems.
posted by hattifattener at 8:57 AM on May 15, 2013

Right. The FCC requires broadcast stations to check their transmitters and make sure they are broadcasting at the right levels. If the transmitter is out back, you just go check the dials. If it's at a remote location, you either pay someone to stop in and look at the dials once a day, or you install an automated system like this to read back the levels to whoever calls. You don't want your transmitter that's licensed for 1000 watts on 710 suddenly blasting 50,000 watts on 720. WGN will get angry.

It may be different for FM transmitters, I'm not sure. It's possible the requirements are the same, but that since they are so often co-located with other transmitters, the landlord of the tower provides this service.
posted by gjc at 9:41 AM on May 15, 2013

Call the radio station where you worked, tell them you're a person of authority, and ask for the number. Or be honest with them. It's your call.
posted by Sunburnt at 10:48 AM on May 15, 2013

I remember that at the stations at which I worked in the '70s, we had a microwave link between the studio and the transmitter site that not only upstreamed the studio audio, but downstreamed the telemetry from the transmitter for FCC logs. No voice back then; we had to actually read meters, fine-tune the transmitter output and (after dark) confirm that the tower lights were operational. And HAND WRITE the entries! The horror!

I seem to remember faking the log entries at the end of the shift...oops.
posted by DandyRandy at 1:05 PM on May 15, 2013

Best answer: Repeaters still use the badly-synthesized voices from those TI chips (as used in a speak and spell). Here's a sample (wav) from a CAT-200.
posted by scruss at 3:58 PM on May 15, 2013 [1 favorite]

Response by poster: Holy smokes, scruss, I think that's it! Magnificent.
posted by Mothra Pisces at 4:37 AM on May 16, 2013