Sunday, September 16, 2007

More HD DX

Well, we now have nighttime AM HD.

Nobody has died. There's still AM radio. We've even had reports of excellent trans-Atlantic conditions.

Indeed, some of us have managed to DX a bit of the digital audio. You see the evidence on the right side of this post.

- KMOX-1120 St. Louis managed to provide about ten seconds of digital audio around 8:40 Saturday night.

- WTAM-1100 Cleveland was in HD for about a minute around 9:40. Their analog was not delayed to match the digital - so every time it faded up into digital I heard what the analog said 8 seconds ago. Bizarre.

- WLS-890 Chicago was only in digital for a second or so this evening. The text ID stayed in a lot longer, allowing this photo. (I had to hit the trigger about ten times to get a usable shot - my hand kept moving the camera... Thank goodness for digital cameras!)

Send in your HD screenshots!


Anonymous said...

There have been plenty of reports of AM-HD jamming - go read the HD boards at radio-info, AVS Forum, ba.broadcast, and and see how popular AM-HD is!

Doug Smith said...

Oh, I don't pretend to believe for a moment that HD is a good thing, either AM or FM. Firstly, because we could have had something better. (Eureka-147) Secondly, because the interference to useful signals is real and will eliminate valid program choices for real listeners.

And I've read the complaints - not on AVS or ba.broadcast, nor on (which seems to have a very low signal-to-noise ratio) but definitely on radio-info and the NRC and WTFDA lists.

But HD Radio is a fact and we, as DXers, are not in a position to get rid of it. Either it will fail on its own (which is what I believe will happen) or we DXers will have to learn to live with it.

And we've lived with interference before. Once upon a time, no station operated seven days a week. Once upon a time, no station operated 24 hours a day. Once upon a time, WSM was the only station on 650KHz. Once upon a time, the radio was the only electronic device in your home.

Of course, none of these are true anymore. And some of the spectacular DX - like coast-to-coast reception of "graveyard" stations - is a thing of the past. But there's still DX, and still DXers chasing it. The hobby changed through these developments, and some DXers did leave the hobby. Others stuck with it, and we still have DX today.

Even if IBOC does survive in the long term, it will only change the DX hobby - not kill it.

Organization said...

It would seem to me that the hobby will now have the added thrill of QSL'ing using images of received program data. Are there folks using images for QSL cards? DO broadcasters still send them?

I found your blog today while researching AM HD. The move to 24x7 AM HD caught me off guard I'm afraid. I enjoy analog content where I live but now WABC is hammered by HSRI -HD Radio Interference.

Has anyone written on how well AM HD works at great distances? based on what I am reading you need to be in an interference free environment within 15 miles or so of the AM station.

Doug Smith

Organization said...

That should rad HDRI.

Doug Smith said...

Geez, there's another Doug Smith in radio?(grin)!

"Are there folks using images for QSL cards?"

If you mean images from HD Radio PAD displays or analog RDS displays, not that I know of. We probably should.

"DO broadcasters still send them?"

I assume here you mean paper cards. A small number do still send them. Most will provide written verification if you send an accurate report and SASE (and most will return the SASE unused) but usually the verification is in the form of a letter on station stationery.

Given that, especially on FM & TV, DX reports are relatively rare, I think it's probably not reasonable to expect stations to have QSL cards anymore.

"I found your blog today while researching AM HD. The move to 24x7 AM HD caught me off guard I'm afraid. I enjoy analog content where I live but now WABC is hammered by HSRI -HD Radio Interference. "

It sure didn't see much publicity outside DX circles.

"Has anyone written on how well AM HD works at great distances? based on what I am reading you need to be in an interference free environment within 15 miles or so of the AM station."

I've tried to keep up with it in my Monitoring Times column. There has been a bit of DX before the recent deadline; stations were allowed to begin HD broadcasts at 6am and leave it on until 6pm, allowing some sunrise/sunset DX. Also, occasionally a station's timer would fail and their HD would remain on overnight.

In my experience, yes, for the most part reliable AM HD reception requires a pretty clean signal - I have to use a rather long ham antenna to get HD reception of my two closest AM HD stations. (about 20 miles away) FM seems to work a bit better, but I still can't get the FM HD of a Class A station 20 miles away whose analog is quite clear.

Some of this will clean up if stations are able to leave the current hybrid mode and switch to full digital mode. (allowing a substantial digital power increase)

However, that means turning the analog signal off, and right now that means pretty much your entire audience will disappear(grin). It will take a very long time to see full digital mode; I will be surprised if it ever happens.

Anonymous said...

"What Are We Doing to Ourselves, Exactly?"

"IBOC FM Interference Has Been Reported in Several Cases Where FCC Contours Provide Inadequate Protection."

"HD Interference: Not Just For AM Anymore"

"Radio World Engineering Extra dropped a bomb this month with a very provocative cover story: 'What Are We Doing to Ourselves, Exactly?' Written by Doug Vernier, the man who authored the technical specifications for an ongoing Corporation for Public Broadcasting-sponsored HD Radio interference analysis, the report is the first of its kind to document interference between FM-HD stations around the country. Using anecdotal reportage, some sophisticated contour-mapping, and presumably 'early data' from the CPB study, Vernier's article conclusively proves how stations running in hybrid HD/analog mode can (and do) interfere somewhat significantly with not only themselves, but their neighbors on the FM dial."

"Citadel Halts AM Nighttime IBOC Operation Amid Complaints"

"An excerpt from his memo to staff reads: In response to the lackluster performance, the limited benefit and various reports of significant interference, Citadel is suspending nighttime AM HD operations at this time. Please reinstate your previous procedures for daytime-only HD operation as soon as possible.”

"Editorial: AM IBOC in Distress?"

"Citadel Director of Corporate Engineering Martin Stabbert embodied questions about the efficacy of full-time AM HD when he ordered all his AMs that had already converted to cease transmitting HD at night, using language that must have given Ibiquity officials heartburn. Separately and for different immediate reasons, Cox, in a “let’s wait and see” move, has tried HD on most of its AM stations but is taking it off the air day and night, once tested at each facility."

"AM Broadcasters Back Away from HD Deployment"

"This is a major setback for the adoption of HD Radio, especially on the AM dial, and Citadel is the first large broadcast conglomerate to back away from full deployment of the HD broadcast technology. Although the company's gone out of its way not to characterize its move an indictment of iBiquity's proprietary digital broadcast standard, the problems with AM HD broadcast interference are well-known and -documented."

You were saying, IBOC-shill?