Pete KE9OA wrote:
I agree on the point of myself having any appreciable effect. I did receive
an e-mail response from Mr. Miller of the FCC this morning. He wants me to
send him some spectrographs of the stations in question. I am going to see
if I can take one of the 8560 spectrum analyzers home for a day or two. This
way, I can use the marker function and show the delta between the carrier
and the adjacent channel sideband power. The VSA would be even better,
because it could measure ACCP (adjacent channel coupled power).
I did get a response from one of the managers from WTMJ 620 this afternoon.
Nothing from WBBM yet, but I won't hold my breath on this one.

WTMJ is certainly a smaller group, and I don't think they have the
financial interest in Ibiquity some of the larger groups have.

I *have* heard reports of IBOC signals splattering out considerably
further than the theory suggests they should. (for example, of "FM"
IBOC stations trashing 2nd and 3rd adjacents - which shouldn't happen)
I can certainly see where problems in the transmission system can cause
that, and since this is a new mode I'd bet a lot of engineers aren't yet
familiar with what can go wrong.

I doubt you'll get any action from a spectrum analyzer plot that shows
all its energy within 15KHz of carrier. However, I wouldn't be
surprised to see some outside that range, and I can see the FCC acting
on that.

I do believe that if many people expressed their concern there would be a
very small chance that it would have some effect. Unfortunately, money makes
the world go around and if the radio stations think IBOC can increase their
revenue they will go for it.

I think they're grasping at straws, hoping IBOC can stave off
competition from satellite. (much as AM station operators hoped analog
AM stereo could stave off competition from FM)

I just hope it fails quickly enough to not kill off the service entirely.

--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

Ham stuff for sale:
http://www.w9wi.com/articles/4sale.htm

It would be good if IBOC fizzles out sooner than later. In my correspondance
with WTMJ, I did tell them that I can phone them and actually play one of my
radios............demonstrating that actual level of interference.
We as SWLs are more aware of this type of interference because the receivers
we use are sensitive enough to hear that interference in the first place.
WTMJ's sideband noise is at the 30uV level here in Waukegan Illinois, and
many of the "household" radios that you find in homes aren't going to detect
that low of a level. Exceptions are some of the better auto radios.
It is a shame about that interference but, maybe it won't be forever.

Pete

"Doug Smith W9WI" wrote in message
...
Pete KE9OA wrote:
I agree on the point of myself having any appreciable effect. I did
receive an e-mail response from Mr. Miller of the FCC this morning. He
wants me to send him some spectrographs of the stations in question. I am
going to see if I can take one of the 8560 spectrum analyzers home for a
day or two. This way, I can use the marker function and show the delta
between the carrier and the adjacent channel sideband power. The VSA
would be even better, because it could measure ACCP (adjacent channel
coupled power).
I did get a response from one of the managers from WTMJ 620 this
afternoon. Nothing from WBBM yet, but I won't hold my breath on this one.

WTMJ is certainly a smaller group, and I don't think they have the
financial interest in Ibiquity some of the larger groups have.

I *have* heard reports of IBOC signals splattering out considerably
further than the theory suggests they should. (for example, of "FM" IBOC
stations trashing 2nd and 3rd adjacents - which shouldn't happen) I can
certainly see where problems in the transmission system can cause that,
and since this is a new mode I'd bet a lot of engineers aren't yet
familiar with what can go wrong.

I doubt you'll get any action from a spectrum analyzer plot that shows all
its energy within 15KHz of carrier. However, I wouldn't be surprised to
see some outside that range, and I can see the FCC acting on that.

I do believe that if many people expressed their concern there would be a
very small chance that it would have some effect. Unfortunately, money
makes the world go around and if the radio stations think IBOC can
increase their revenue they will go for it.

I think they're grasping at straws, hoping IBOC can stave off competition
from satellite. (much as AM station operators hoped analog AM stereo
could stave off competition from FM)

I just hope it fails quickly enough to not kill off the service entirely.

--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

Ham stuff for sale:
http://www.w9wi.com/articles/4sale.htm

Pete KE9OA wrote:
It would be good if IBOC fizzles out sooner than later. In my correspondance
with WTMJ, I did tell them that I can phone them and actually play one of my
radios............demonstrating that actual level of interference.
We as SWLs are more aware of this type of interference because the receivers
we use are sensitive enough to hear that interference in the first place.
WTMJ's sideband noise is at the 30uV level here in Waukegan Illinois, and
many of the "household" radios that you find in homes aren't going to detect
that low of a level. Exceptions are some of the better auto radios.

What the stations are going to say is that you're outside the service
area of the station being interfered with. WSM doesn't deliver a
protected-contour signal to Waukegan, so officially, you can't get WSM
there, and so officially, WSCR's lower digital sideband can't be
interfering with WSM.

(as I understand the rules, right now WSM *does* deliver a
protected-contour signal to Waukegan at night - but IBOC proponents want
to drop all protection for skywave signals. There's no way IBOC can be
authorized at night on clear channels, or on 1st or 2nd adjacents to
clear channels (like 620), if they don't.)

But it sure seems to me like AM IBOC already is - during the day -
causing interference within the protected groundwave contours of
existing stations.

A new station (WCKD) came on the air on 1490 in Lebanon, Tenn. around
the first of the year. That's about 40 miles from the WLAC-1510 tower.
On a hunch, I drove over there last weekend.

On a typical car radio (factory radio in 2002 Ford Focus) there was
noticable IBOC QRM on WCKD *within the Lebanon city limits*. Again,
this is on a typical consumer radio - not a hypersensitive DX setup.

Again, as I understand the rules, a station (like WCKD) will not be
authorized unless its city-grade signal encompasses the entire city of
license. The city-grade contour is even smaller than the
interference-protected contour - in other words, WCKD's protected
contour extends beyond the city limits.

In other words, if I understand the rules properly, at least one
"AM"-IBOC station *is* causing interference within the protected
contours of an analog station. I would be very surprised if this is the
only example. I *believe* I've heard interference in the protected
contour of WJJM, Lewisburg (also on 1490) but haven't actually driven
*into* Lewisburg to verify.

Certainly, WCKY-1530 has ceased to be a listening option until WLAC
turns off their HD around 5:00...

FM, IMHO, is much less of a problem. Still, I think many listeners
(especially in further out suburbs, like Waukegan, and outlying cities
like Clarksville) will be surprised to learn they can't officially get
their favorite stations. (the battle between the sidebands of co-owned
96.9 Zion and 97.1 Chicago will be interesting...)

I expect to lose my only adult-alternative and my only jazz choices if
FM-IBOC is fully deployed.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

Ham stuff for sale:
http://www.w9wi.com/articles/4sale.htm

Well,WSM,I can pick up,no sweat.Waukegan,I have been through Waukegan
before on a Greyhound bus in December of 1956.Hey,do you know that old
song thingy,Big Noise From Winetka? I remember some of it.Do you? It's
kind of a catchy little tune.One time about ten years ago,I was in a
home building products store in Jacksonville,Florida and I was whistling
that tune.There was a woman from the Shytown (Chicago) area sitting
there at the information desk.She started whistling it too.
cuhulin