First day of Nightime IBOC

[Len14043]

Has anyone noticed degraded local serice yet? There are no local nighttime signals where I live (or any local daytime service for that matter) so I cannot check that out.

Absolutely. KFXR 1190 Dallas is destroyed in its protected countours by WOAI.

I am also getting amazing levels of sidebands on other frequencies, including a local 700 that seems to be attacked by WOR's sidebands. Amazing stuff!

I repeat my call for a meltdown. Let's put all AM's in this hybrid mode, and see if the band is even usable.

Could it be a local running IBOC that is putting a digital harmonic on 700? For instance, WLW puts a analog harmonic on 1400 and the digital sidebands can be heard on 1390 and 1410 when close to the tower.

 

[radio-outsider]

How to really save the AM band.

The FCC should expand the FM band to include the all-but-vacated VHF TV channels 5 and 6 (74-88 Mhz), allow all existing AM broadcasters to simulcast for a period of years in this new band until the expanded band receivers reach critical mass, at which point they would surrender the AM license.

Then reassign AM to a couple of hundred high power non-directional (or softly directional) semi-clear channels with 2000 mile co-channel seperation and 1000 mile adjacent channel seperation. Each state would get a least one station. The balance would be allocated based on population. The top 10 markets might get five stations each, etc. Nighttime programming would be locally produced.

Rather than IBOC, the seperations would support much wider bandwidth per channel, allowing much better fidelity.

The bottom line is that many more people would get more stations with higher quality reception and fidelity, and a broader variety of progamming.

The future for the AM band as it currently exists, even without IBOC, is dismal, but for the few WABC's, KGO's, WBZ's, etc. Ther rest are a waste of real estate and electricity.

 

[4dude]

Thats a good idea!

Open 76-87Mhz and let all HD ONLY stations go there!!!! (Get them off the am band)

 

[DG02816]

Zach,

The 'other' station you hear on 740 may well be that of CHWO, Toronto. 50 kW into a half-wave high tower at that frequency gives you a massive signal.

 

[rbrucecarter5]

Could it be a local running IBOC that is putting a digital harmonic on 700? For instance, WLW puts a analog harmonic on 1400 and the digital sidebands can be heard on 1390 and 1410 when close to the tower.

Interesting question - but subharmonics are not as common as multiples. There is no real mathmatical model that would produce a 1/2 harmonic in a Fourier series.

Also, we have no viable station on 1400 that would divide by 2, although we do have a 1440 that - if it had a subharmonic - would show on 720. But it doesn't daytime, so nighttime is unlikely.

I'm not saying it wasn't another 710, but the geometries would have to add up the same as a signal from New York.

 

[gr8oldies]

Last evening on a standard car radio, I would have to say it wasn't as bad as it could have been. In Springfield, OH I noted some of WOR's hash under WLW, but it wouldn't be enough to annoy anyone who wasn't specifically looking for it. I still could get CINF under WLW's hash, and even WOR through the hash on the other side (strange but it actually seemed as though the nighttime hash wasn't as loud as during the day from WLW. 720 had WGN mixing in with hash rapidly fading in and out. 730 was obliterated; I could hear WABC OK but WJR was weak and had some hash. I got WSB and WBBM. I noticed a good bit of hash on WSM from WFAN. KMOX was in strong and so were their sidebands, killing 1110 and 1130. The Dayton area locals are weak in Springfield anyway at night, and I did not notice any difference, nor adjacent hash. No hash noted from WLAC.

 

[pianoplayer88key]

My preference for HD / digital radio has basically always been something like:

If, with a decent-quality radio and Bruce Carter's best loop antenna (or a better antenna if there is one) you could detect ANY hint of a signal at all from a station (even if it was just a faint carrier and no intelligible audio was heard), then with an average-price HD radio that station should come in crystal clear with its built-in antenna.
And, for frequencies with multiple stations on the same frequency (and part of this I just thought of the other night), for example the graveyards, the stations send some inaudible code (for example a type of QRSS callsign in morse code, with the tones at, say, 6 Hz), then with your tuner you can select which station you want to listen to.
For example, from San Diego, CA, I would expect to receive 660 KGDP Orcutt, CA, 680 KNBR San Francisco, CA, 740 KCBS San Francisco, CA (even with KBRT on the same frequency), 810 KGO San Francisco, CA, 1530 KFBK Sacramento, CA, 1580 KMIK Tempe, AZ (with KBLA on the same frequency), in HD with this type of system.
Also, I would want it to be able to permit analog stereo systems to operate concurrently, and I wouldn't want it to interfere in any way with analog broadcasts (for example if you're 10 feet from the tower of a 50kW digital only station on 700, and there's a distant 5kW station 200 miles away on 690 that you can barely hear with the 700 off the air, you still would be able to hear that 690 just as well with 700 HD-only on the air.)