HD Radio is NOT Sirius and it is NOT DX

[Ai4i]

1. The Commission was quite willing to allow it. Congress passed their own legislation to nix the idea.
2. All the clears have been broken down since the last bout with super power AM
3. The increase in signal strength is plain and simple. With a 10dB increase in transmitter power, the field strength goes up by an equal 10dB for all points in space.
4. Too late to do it in the lower forty eight, it really should happen in Hawaii, but especially in Alaska where almost every AM maintains their daytime power level twenty four hours AND very very very few AM's are directional.
5. The idea was finally laid to rest in 1975 here.
6. Satellite Radio is the twenty first century solution of how to have stations with continental coverage. A fan of local radio, I support allowing local content to be offered from terrestrial repeaters.

 

[Savage]

"With a 10dB increase in transmitter power, the field strength goes up by an equal 10dB for all points in space." True, comparing 50kw vs. 500kw signals at identical distances from the transmitter. IOW, plot a given contour at 50kw and you would see a linear increase at the same points on the same contour at a half-megawatt.

But the AM groundwave at ANY power is rapidly attenuated by local conditions including manmade and natural obstructions, development in urban areas, power distribution systems and decreased ground conductivity vs. the M3 in many populated areas, and decreasing steeply with distance from the transmitter. I was thinking of typical AM listening conditions. I would still maintain most people would be startled by how undramatic reception improvement would be with ANY tenfold increase in AM Tx power, like 500 watts to 5000 watts as well as 50 kw to 500kw. With 500kw the most noticeable improvement would be far out of the station's home market. In the area of license if 50kw provided serviceable reception 500kw wouldn't make much difference to a typical listener.

I think it's an academic question, since increasing to AM superpower isn't under serious consideration that I'm aware of. But it occurs to me absurd directional systems would be required given the population of stations today. "500kw, thirteen towers....no thanks..."

 

[Ai4i]

"500kw, thirteen towers....no thanks..."

I wonder what the forward ERP of that dozen tower station on 1190 in Dallas is.
The joke is that you can hear them all along Main St, but not on the sidewalks.

You are absolutely correct about the diminished return.
The purpose would not be to enlarge the coverage, rather that listeners in questionable areas which, in the case of skywave areas could be huge, would benefit. Anything beyond the first skip would have objectionable fade distortion regardless of power. Ask the Russians about this 2.5 Megawatt station.

 

[R.F. Burns]

dumber than a box of hair aptly observed:

Quote from: R.F. Burns on Yesterday at 06:06:48 pm

I have to step in here and clear some things up because obviously no has cleared up the confusion that you have.

The only person here who appears to be confused is you, because no one mentioned AM's transmitting from Manhattan.

Boy I sure do agree with THAT observation!

Quote from: R.F. Burns on Yesterday at 06:06:48 pm

NYC is loaded with HD stations on AM and many more on FM and also most are running HD 2 channels and also HD 3 channels. WFAN, WABC, WCBS, WINS are all available on NY HD 3 channels, so AM radio in Manhattan is unimportant becuase these four stations also do AM HD. The only other AM HD station in the city is WQEW and they are Radio Disney. If that's what you want enjoy. If you want the other AM HD outlets check out their HD 3 channels.

Have you been living in a bomb shelter for the last ten years? Pronouncing AM "unimportant" because AM signals are being simulcast on HD secondaries is just about the funniest/most pathetic thing I've seen here. The multi-millions of people in the NY metro who don't have HD radios and who listen to AM *ON* AM would just shake their collective heads in amazement over anything so completely out of touch with reality. Considering that, according to the HD folks, a measly one million radios have been sold (vs. 800 million-plus analog radios already out there), HD isn't even making the tiniest dent...and now you come along and pronounce AM "unimportant."

Thanks for the best laugh of the day.

Wow, I don't think that is funny at all. Poor Mr. Burns. Perhaps he has been around a high-RF environment for too long? I know he is employed by a major broadcaster in the #1 market and he has all the real facts that us peons can't even begin to fathom but maybe it is possible that the company for which he works is just making him crazy. I know if I worked for his company it would likely make me crazy too!

The old R.F. used to applaud IBOC as the technology that would save AM radio from becoming obsolete and now that it looks like IBOC has actually ruined AM radio reception instead, he continues to make excuses for this sorry product to the extent that AM doesn't matter in the urban jungle anymore because you can get some of them on FM HD-3 now! Well now, that is so sad! Madness manifests itself rather slowly. No wonder he has been so quiet lately!

He sure does sound angry though, don't you think? I guess if I had said all the things he has said (using several different alter-egos) over the past few years and then found out that I had been taken for a ride, I guess that I would be angry too! Those naughty, naughty IBOC people. They stretched the truth and tried to change the laws of physics and I fell for it, hook, line and sinker.

Wow I must have hit a nerve. Forgive me for holding an "OPINION" That differs from your first hand knowledge of reality.