In the otherwise excellent article “Rebuild
That Relic of an AM Transmitter” (Oct. 19), I may have misunderstood the two
images of an oscilloscope display that author Mark Persons uses to illustrate
asymmetrical modulation in an AM transmitter.
Often such modulation is considered
reduced carrier in proportion to the sideband energy, and that’s how I look at
a waveform to compare. His example of 125 percent modulation seems to be
over-modulation and hitting baseline in the negative direction, a condition
that causes splatter and distortion.
| 100% Modulation. Tubes with good emission give low-distortion results.
| 125% Modulation. The audio is turned up another2 dB.
Instead, I would have expected to see
positive peak energy without hitting baseline covering more vertical gradicules
in the asymmetrical example than in the one showing 100 percent modulation.
Paul Courson, WA3VJB
Mark Persons replies: When testing AM
transmitters, I look at the negative and positive modulation capability. Seeing
the positive peaks go to 125 percent while achieving a full 100 percent
negative is the desirable result of over-modulating the transmitter by 2 dB.
That is done by putting a tone directly into the transmitter without any audio
processing. Yes, it will cause splatter at that point. Once I know the
transmitter can produce high positive modulation, then I know the audio
processing can be set to limit to just under 100 percent negative modulation
and allow positive peaks to achieve 125 percent modulation with program
material. No splatter then and it fully makes FCC requirements.
Regarding “Radio Great Norman Corwin
Dies, Age 101” (Oct.
Corwin’s professional legacy is secure,
rooted in the gemlike quality and eternal nature of his body of work; his
living legacy lies in the countless lives he touched with his enthusiasm to do
better, to improve the small corners of the world we inhabit. He was, and
remains, a beacon for those who believe in the power of optimism to nurture the
better angels in our daily lives.
Long may he live in our memories and on
Vic Cox profiled Norman Corwin in Radio
World’s Jan. 12, 2011 issue.
Kudos to John
Schneider and the historical remembrances he brings to the page.
picture of the KRLD transmitter, published in the July 1 issue and reproduced
on the letters page in the Oct. 19 edition, has a particular pleasing feature
for me. I am referring to the pale blue FCC certificates on the wall.
First Phones. The way it should be.
John Schneider replies: I’m glad you
liked our “colorized” image; it seems so much more real in color. I tried to
reproduce accurately all the known colors and went to some effort to match the
FCC blue correctly. The transmitter cabinet color was extracted directly from a
color photo of a WE transmitter that I found on the Internet. I had to guess on
some of the auxiliary equipment in the racks.
Like a Performance Wrong
Just read the comments of Maria
Pallante (“Copyright Office Still Backs Performance Right,” Radio World
NewsBytes, Oct. 26). Here is another government official with no work
experience, especially none in broadcasting or even the music industry.
Someone needs to teach her about the
role of ASCAP, BMI and SESAC in the daily operations of broadcast stations. She
needs to read some of our contracts ... and maybe she needs to see how big some
of the checks are that broadcasters send to these music owners every month of the year.
And she needs to talk to recording
artists and simply ask them what their careers would be like if their songs had
never been played on radio, TV or
cable. What other industry pays a chunk of its gross income (in our case, 8
percent) to the music industry and then also provides free airtime to promote their products?
General Sales Manager
Not Broke So Don’t Fix It
In the Oct. 19 issue, Dan Mason of CBS
Radio says he’s concerned about AM radio. Bruce Reese of Hubbard says convert
AM to digital and problems go away (“AM’s Future,” News Roundup).
The problem that needs to go away is
input from large corporate owners. Every time they buy into some “newfangled”
idea, it costs me money, but nothing changes other than my bottom line.
We have a 1 kW AM, analog, gospel and
sports programming. None of my listeners complains about not hearing us in
Citadel, Clear Channel and others stay
in the bankruptcy line because they buy into every piece of junk that is
presented to them. The FCC isn’t much better.
Most of the radio mess is a result of
too many worthless 100 kW FMs, the FCC allowing FM/AM combos to be split and
sold off, the destruction of local radio by the corporate giants and
translators being bought up and held for more profit.
Our station is profitable, sounds good,
pleases our community and we have fun.
What needs to happen is simple. No FMs
over 25 kW. Every standalone AM gets an FM translator that when assigned is a
part of the AM license and can never be sold away from the AM and must
simulcast 100 percent of the time.
Our station is in the Baton Rouge
market, which like many other markets has way too many radio stations because
of corporate ownership. I would like to have a simple 100 watt translator to
cover our area at night, but because of corporate manipulation of the FCC, the
FM spectrum in Baton Rouge and New Orleans overlaps and there are no FM
allotments for anyone. Our people suffer and no one cares.
I pray I live long enough to see the
corporate giants finally buy themselves into total bankruptcy and have to
divest themselves of about 90 percent of their holdings.
We like serving our little area. Our
EAS plan is second to none. Our local governments can activate an EAS and
access our transmitter for an unlimited amount of time and not have to listen
to some overpaid moronic program director whine. We have been EAS-compliant for
months and welcomed the national test. Our local system has been tested and
works flawlessly. Our people are safe. There is not one radio station in Baton
Rouge or New Orleans that will outshine us in an emergency situation. Katrina,
Gustav and tropical storm Lee proved this beyond a shadow of a doubt.
So I say leave us alone to do what we
do best: serve in the public interest with our analog signal that works just
fine. It’s not broke so don’t try to fix it.
Baton Rouge, La.
Speech and New Media
This is in response to Craig L.
Parshall’s opinion article regarding the John Milton Project (“New Media Has a
Free Speech Problem,” Nov. 2).
The right to free speech is a right to
speak, not a right to be heard on every media platform you want. If a religious
group’s doctrine is so radical that a media platform feels uncomfortable, you
should look at the content. Are they propagating sexism, homophobia or racism?
In those cases it’s acceptable for them to decline to carry your content.Dismissing this as censorship is
arrogant and entitled.
Being stymied by Apple, Facebook et al.
is frustrating, no doubt. But it’s the same response you might get from a print
publication or from a broadcaster when you bring them questionable content.
This is not overt censorship. They are not obligated to taint their brand
and/or their product with your hate speech. If you want a media platform that
is wide open to troglodyte opinions, build your own, the Internet is a big
place. There’s plenty of room.
Arcane Radio Trivia
I wish some station owner would put something
different on their HD2 stream instead of a “clone” of their HD1 feed. I mean a
totally off-the-wall different format to get new listeners to their station and not just siphon off their HD1
listeners because their HD2 feed has such a similar format.
I’m waiting for a reason to show off my
HD2 to others, as all three HD2s here are merely offspring of their HD1 hosts
Maybe go so far as to hire some Internet
station programming gurus to program your HD2 feed with deep oldies, beautiful
music, all comedy, all weather, all-request super-decades, etc. … and in exchange
for their programming over your group’s HD2 feeds, they agree to cease their
own Internet feeds instead for one branded by your broadcast group and your HD2 OTA status.
If you can’t beat them, join them by
hiring them away from their own feeds, including use of their original
identifiers on your OTA HD sub-channels and your broadcast site links.
John Pavlica, Jr.