The call came in at about 2 p.m. The station was off the air. A
quick listen confirmed that the transmitter was on, yet the station
was broadcasting no audio.
Fig. 1: Dave Radigan uses a switcher to select backup feeds to his
The STL to this transmitter site is via telco lines, so the
staff placed a call to AT&T. The chief then headed to the
transmitter while contract engineer Jim Schultz went to the studio,
just to make sure it wasn’t a failed audio processor.
Over the years, “disaster recovery” is something to which
Jim has accustomed himself. He says their first idea was to
connect an MP3 player, pre-preprogrammed with some IDs, generic PSAs
and music, at the transmitter site until AT&T could scrounge up
someone who had a clue about program circuits.
Of course, that wouldn’t happen quickly. With afternoon drive only
a couple of hours away, it was time to come up with a more immediate
Turns out the station’s stream was up and running just fine, so why
not use a 4G smartphone to feed audio to the transmitter?
One TRS (tip-ring-sleeve) mini plug and two XLR connectors later, the
station was back on the air, with the smartphone’s output feeding
the audio processing at the transmitter. And the station sounded
pretty darn good.
Five hours later, AT&T replaced a power supply in one of its
central offices, and the program lines were back in business.
A smartphone is certainly not the ideal STL; but the station didn’t
miss a spot and the GM was quite happy. Isn’t that what every
engineer wants: happy customers?
As for the commercials: It seems that you can legally air the stream
but not stream the air. There were only two advertisers whose spots
were missing from the stream blacked out, and the GM cleared any
spots from those two advertisers during the time the station aired
Jim is not the only engineer who has thought about using streaming as
a backup STL.
Fig. 2: A streaming receiver provides backup audio should the main
Dave Radigan, president of WEBO(AM) in Owego, N.Y., took his backup
system a step further. Using an audio switcher, pictured in Fig. 1,
Dave can select from his stream, a utility feed or the phone. Fig. 2
shows Dave’s streaming radio, which feeds the switcher.
You can’t have too many backups!
* * *
Jim Schultz also stumbled across a handy item for his “bag of
He had purchased a Tascam DR-40 recorder but was disappointed that
its mic level input was fixed at –19 dB, which was sufficient for
use with normally hotter condenser microphones, but way too low to
give a decent signal-to-noise ratio with popular dynamics like the EV
RE50, EV 635 or Shure SM58.
Two products that correct this problem are Cloudlifter
and the Fethead. Each
offers 20–25 dB of gain and run on phantom power. Originally
designed to help low-output ribbon mics, these are a perfect solution
to the gain issue.
Jim writes that he has no idea why a mic level input would be set at
–19 dB; perhaps the designers felt the recorder would be used
mostly for recording loud music. Jim has a Tascam recording codec
that has the same issues on the Mic input.
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Author John Bisset has spent 44 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.