AM IBOC- Death to low power night station

engineer · Post by **engineer** » Tue Sep 18, 2007 8:55 am

Wow, the IBOC AM stuff is destroying the nighttime sky wave. It's worse than anyone predicted. Also, the two Morgantown AM stations that reduce to low power are getting hammered. This is going to court folks. It's all over the other boards.

Hoosier Daddy · Post by **Hoosier Daddy** » Tue Sep 18, 2007 9:12 am

How many thousands of people -- good, decent, knowledgable technical radio people -- told them IBOC wasn't ready, it wasn't capable of doing all the good things and NOT doing bad things ...

And, of course, my good friends at the NAB spearheaded this whole debacle.

Proof once again that the FCC should quit being an enabler of big business and start doing their job.

Dave Harman · Post by **Dave Harman** » Tue Sep 18, 2007 10:27 am

There have been no problems with WKAZ-AM (formerly WCAW) operating at night with 221 watts at 680. So far.

genlock · Post by **genlock** » Tue Sep 18, 2007 10:50 am

Is an AM iboc radio available?

I thought the stuff to now was FM only?

Hoosier Daddy · Post by **Hoosier Daddy** » Tue Sep 18, 2007 6:06 pm

Dave Harman wrote:There have been no problems with WKAZ-AM (formerly WCAW) operating at night with 221 watts at 680. So far.

Are you talking about KAZ-AM generating or receiving interference?

I didn't know if WCAW was an AM IBOC station yet.

AmpedNow · Post by **AmpedNow** » Tue Sep 18, 2007 6:17 pm

genlock wrote:Is an AM iboc radio available?

I thought the stuff to now was FM only?

Yes. Virtually all of the current HD radio models receive AM HD as well.

The problem on AM is the lack of bandwidth. This is also why HD AMs cannot run multiple streams.

As for nighttime AM IBOC, this is definitely going to court... What was once clearly audible night signals are now virtually nonexistent. Anyone in WV will notice that WBT is all but gone, thanks to sideband hash from WTAM and KMOX. WSB has a constant whining noise on it, no longer listenable. The only clear which has yet to be affected is WRVA, and they are also running IBOC now.

Even the selectivity of the GE Superadio cannot null out the sideband hash. If anything, the sensitivity seems to amplify the hash along with everything else.

And yet, as of now there are only a handful of stations running nighttime IBOC. If you think this is bad, wait until the end of the year...

Ultimately, there are two choices: shut 'em down and wait for the IBOC technology to catch up, or go all digital. We know that all digital is decades away thanks to the bureaucratic process, so that leaves us the former.

The IBOC technology will likely get better in time. But I really think that jumping the gun on nighttime AM is now going to cause them far more trouble than they would've had to deal with, had they just waited for the technology to catch up.

genlock · Post by **genlock** » Tue Sep 18, 2007 6:32 pm

Digital Radio Mondiale.
Give all the AM's at 10 kw and under an FM freq in channels 5&6.
And the other AM's that want it in the 2nd wave.
Re allocate frequencies on the AM band and change rules to
allow for propagation and soil conductivity.
Open up an new band 200 to 400 khz for very high power stations. All digital.
All this has been discussed before.

We just need a lawyer to file this on behlaf of thhe WVRTV message board.

Someone would like it cause it would obsolete all the broadcast radios in the country and sell a lot of new ones.

Hoosier Daddy · Post by **Hoosier Daddy** » Tue Sep 18, 2007 8:18 pm

Genlock for President

Dave Harman · Post by **Dave Harman** » Wed Sep 19, 2007 8:23 am

Hoosier Daddy wrote:
Dave Harman wrote:There have been no problems with WKAZ-AM (formerly WCAW) operating at night with 221 watts at 680. So far.
Are you talking about KAZ-AM generating or receiving interference?

I didn't know if WCAW was an AM IBOC station yet.

Sorry I wasn't clear about that. WKAZ-AM is not IBOC yet. I'm receiving it at night from about 15 miles away with very little interference.

Hoosier Daddy · Post by **Hoosier Daddy** » Wed Sep 19, 2007 10:52 am

Dave Harman wrote:Sorry I wasn't clear about that. WKAZ-AM is not IBOC yet. I'm receiving it at night from about 15 miles away with very little interference.

That's a decent haul on 221 watts.

Dave Harman · Post by **Dave Harman** » Wed Sep 19, 2007 1:02 pm

Hoosier Daddy wrote:
Dave Harman wrote:Sorry I wasn't clear about that. WKAZ-AM is not IBOC yet. I'm receiving it at night from about 15 miles away with very little interference.
That's a decent haul on 221 watts.

That's the "680" part of the equation

AmpedNow · Post by **AmpedNow** » Tue Oct 02, 2007 6:01 pm

http://www.orbitcast.com/archives/abc-c ... -iboc.html

ABC Citadel suspends AM IBOC?

Tuesday, October 2, 2007 at 2:35 PM

An e-mail from ABC-Citadel corporate engineering has reportedly issued an order effective this morning to suspend AM In-band on-channel (IBOC) operations, according to Radio-Info.

The communication came from Citadel's Martin Stabbard, according to sources.

The order, effective immediately, is reportedly for all Citadel AMs running IBOC at night. While no reason was given for the order, it is believed that interference issues are the most likely factor.

IBOC is the method in which iBiquity utilizes to broadcast the HD Radio signal - using sidebands to transmit the digital data over AM/FM waves. But since wider channels are required, both the AM/FM implementations of the iBiquity system often cause interference with adjacent stations on the dial. As a result, lower power stations can become unlistenable if they have an HD Radio station on an adjacent channel.

[Radio-Info]
Thanks Karl!

UPDATE: Apparently Citadel/ABC's AM stations will suspend nighttime HD Radio transmission until they can do further work with iBiquity to reduce adjacent-channel interference. Radio-Info adds that, "the FCC allowed nighttime AM digital as of September 14 - and the complaints have mounted up."

I suspect that this is the first of many...

And nighttime HD AM has only been approved for about three weeks, with only a fraction of the HD AM stations leaving it on all night.

Looks like Citadel is attempting to head this disaster off at the pass.