IBOC AM Power Output
J
Obviously he's in iBiquity's pocket, but still some interesting data on
the amount of power that IBOC's digital sidebands theoretically adds to
adjacent AM channels.
The full text of his report (including optomistic editorial comments at
the end) is available here : http://www.am-dx.com/iboc_power.htm
Here's an excerpt:
EXPERIMENT AND RESULTS.
To confirm these numbers, a transmitter manufacturer conducted a test
at my request. Using a waveform
independent, true-RMS power meter, total power in a properly adjusted
IBOC AM transmitter was measured with unmodulated carrier and all
digital carriers turned OFF, and again with all digital carriers turned
ON. The tests confirmed the math above: RMS power on either sideband
was 16.2 dB below unmodulated carrier, and RMS power within the full
band was 13.2 dB below unmodulated carrier. This was also repeated
using a calorimeter, which is truly bandwidth agnostic, and the same
results were observed. So I'm fairly confidant that -13.2 dBc for on
band digital to analog, and -16.2 dBc for first adjacent digital to
analog, are the right numbers for true RMS power of the digital
carriers in a properly adjusted AM IBOC system. Just remember these
refer to an unmodulated carrier in HYBRID mode, that is, analog and
digital co-existing on channel.
leansto...@democrat.com
Tell me there is no pure digital mode in the spec.
John Higdon
"leansto...@democrat.com" <leansto...@democrat.com> wrote:
> Tell me there is no pure digital mode in the spec.
The (current) hybrid mode is the camel's nose under the tent. The
ultimate Nirvana for the IBOC faithful is pure digital. In fact, now
that it is totally apparent that IBOC is creaming other stations, the
call is already out to just do away with analog as soon as possible.
In other words, the whole point of this exercise was to ultimately have
all digital on the air and to do it without any non-incumbent
interlopers getting a toehold.
--
John Higdon
+1 408 266 4400
leansto...@democrat.com
Insanity cubed. That will kill AM.
Having bought a new car recently, I didn't see HD as an option. I
consider that a good sign. Both XM and Sirius are options on new cars.
Some vendors only supply one flavor, while others sell both.
Speak of the Devil, Howard Stern is free on Thursday via streaming from
the Sirius website.
John Higdon
"leansto...@democrat.com" <leansto...@democrat.com> wrote:
> Insanity cubed. That will kill AM.
Allowing the hybrid mode at night will kill AM first.
Steven
John Higdon wrote:
> In article <1161845146....@i42g2000cwa.googlegroups.com>,
> "leansto...@democrat.com" <leansto...@democrat.com> wrote:
>
> > Insanity cubed. That will kill AM.
>
> Allowing the hybrid mode at night will kill AM first.
No it won't! It will start the bitchfest to end all and some of these
guys will wake up and get their asses in gear again. If there had been
this crazed leg-humping frenzy to do this Boise would be bleeding it by
now instead of mostly BSU Radio. You said sanity would prevail, and it
did for the most part. KBOI never bit. KGEM seems to have quit. I don't
know about KFXD, I haven't listened since I heard it on my 1961 or 2
twin speaker Airline and my quad and chewed out the engineer swearing
about tincans, telephones and NBC Blue. Well, it got a little better a
couple of days later...He's been there at KIDO since the sixties,
maybe...doubt he likes it either. Actually, I could bet he helped put
KIDO (KTVB [TV]) on the air in '53.