Audio
Recordings of FASTROAD SFN FM HD Radio Tests Now Available
In August 2011,
a technical
report containing the final results of an FM IBOC digital
booster test program was released by NAB FASTROAD (see the August
1, 2011 issue of Radio TechCheck for additional information).
Last week, three streaming video files containing audio recordings
from the Boston, Mass. area field test portion of this program
were made available on the FASTROAD Web page. These were authored
by iBiquity Field Test and Implementation Manager Russ Mundschenk,
who was also in charge of the laboratory and field testing of
the digital booster technology.
These recordings
offer an opportunity to experience how the digital booster impacts
the received analog audio quality for three different scenarios
as a test vehicle drives towards the booster site. Since the digital-to-analog
signal ratio will be increasing above the nominal -20 to -10 dBc
value as the receiver gets closer to the booster, the quality
of the received analog audio in this situation is of interest.
In each case
the booster signal is augmenting the hybrid HD Radio signal from
WKLB's main transmitter. The first two scenarios involved use
of a digital-only (i.e., no analog component) booster's effect
on the main transmitter's analog signal as received on a Chrysler
and a Delphi automotive receiver. The third scenario examines
the effect of adding a low-power, synchronized, FM-modulated,
analog carrier to the digital booster signal, to reduce the analog
host interference caused by the digital carrier in the immediate
vicinity of the booster. The recording for this third case was
of analog audio as received on a Delphi automotive receiver.
Each
receiver's audio was integrated with an animated Google Earth
rendering of the route and an animated, synchronized copy of a
chart indicated the predicted digital-to-analog signal power ratio
at the receiver, as shown in the image at right. For all three
scenarios, the digital-only booster was operating at a power level
of 27 watts ERP; for the third scenario, a 3 watt ERP analog signal
component was added to the digital booster's output.
To access
these video files, go to the FASTROAD
projects Web page and scroll down to the "Single Frequency
Network Analysis" project. The hyperlinks for the individual
files are as follows:
WKLB
SFN Compat Dig-Boost - Delphi
WKLB
SFN Compat Dig-Boost - Chrysler
WKLB
SFN Compat Hybrid-Boost - Delphi
NAB
Accepting Nomination for 2012 NAB Engineering Achievement Awards
NAB
is currently accepting nominations for the 2012 NAB Engineering
Achievement Awards. Established in 1959, the NAB Engineering Achievement
Award is presented each year to an individual for their outstanding
accomplishments in the broadcast industry. In 1991, NAB began
giving awards separately for achievements in radio and television.
The award winners will be recognized at the Technology Luncheon
at 2012 NAB Show on April 18 in Las Vegas, Nev.
Additional
information and a nomination form are available on NAB's
website. The deadline for nominations is January 23, 2012.

The October
31, 2011 Radio TechCheck is also available in an
Adobe Acrobat file. Please click
here to read the Adobe Acrobat version of TV TechCheck.