FM HD Radio May Be Finally Paying Off in this Area

It's also about power issues what is it 1% of the main signal, example WCBS-FM uses only 67 watts for their HD signals. How do broadcasters expect to gain listeners with little power. The flame throwers make out better it seems, in Philly the rimshot FM's STW uses 470w and JBR 500w which give them city grade HD signals in Center City 30 miles away.

Is it true that some of the car radios that come "standard" with HD don't get all the HD signals? I thought I read on one of the auto manufacturer's sites (maybe Subaru or Ford) that they get HD1 and HD2 signals. I took that to mean that HD3 and HD4 could not be picked up in the car. Anyone have experience with that?

I have a new Ford Taurus and I get all sides the only two stations in the area are WOGL and WSJO that have a HD4 and they come in. Now the fly in the ointment is when I get super close to the transmitter of these HD's, within a mile or so the HD goes off lol don't know why but in center city when close to WMMR's xmtr it flips to analog same when I'm in Roxbourough near all the other signals, the HD shuts off. This happens until I'm over a mile away then the HD comes back on go figure..on my HD portables and on my table units it's fine.

DavidEduardo said:

HD channels are part of a single signal with finite bandwidth. The station allocates the bandwidth.

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Sort of. There are two partitions available, P1 and P3, if you are running in Extended Hybrid (MP3) service mode. You can't span a service across the partitions. The P3 carriers are from Fc+/-115kHz to 129kHz after which the P1 carriers begin to the edge of the channel at Fc+/-198kHz.

The P1 partition is 96 kbps and P3 is 24 kbps. If a station has MPS, an SPS1 (HD2), and SIS and ancillary data services in P1, as is common, and SPS2 (HD3) in P3, the HD3 will be limited to 24 kbps. If you try to run more MPS or SPS1 bandwidth by putting ancillary data in P3 you'll further limit the SPS2 allotment because it has to come out of what is left of the 24 kbps bucket for P3. The other issue is that P3 is subject to higher levels of analog host interference (especially if the station has a 92kHz SCA) so it can be less robust than P1.

DavidEduardo said:

Digital power coverage does not match, watt by watt, analog coverage.

WSTW is a 47,100 watt signal. WCBS-FM is a 6,700 watt signal. Both have the same HD signal equivalency.

WJBR and WCBS-FM are both Class B FMs, with the lower WCBS-FM analog power and height combination being the equivalent of that of WJBR. WJBR is not a "Flame Thrower" as it is a fully conforming Class B, just like CBS-FM.

FM stations on VHF frequencies can use, per their class, lower power and higher antenna height. The standard for a Class B is 50 kw at 500 feet. Stations that want higher antennas reduce power but generally have identical coverage areas.

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Injection level should be mentioned here. 1% of analog power is the original -20dBc injection level for HD. -14dB is more typical for newer installations, or 4 times the HD power of what it was originally. Some stations, not many in the congested northeast, can run up to -10dB or 10% injection, or can run asymmetrical sidebands between -10 and -14dB depending on interference caused to adjacent channels. All stations can run -14dB, except that grandfathered superpowers are limited to injection as calculated for their class maximum ERP.

-14dB tends to provide HD service equal to analog service (e.g. no loss of lock to the analog service contour). -10dB outperforms analog.

Huge HD radio fan and I dont get why its so under rated. Glad to see this thread take off. Few observations.

-92.3 HD2 K-Rock has definitely picked up more commercial stops. Way more frequent than a few years back. The breaks seem longer too than just 30-60 seconds. Is that a sign of any sorts?

-On Long island you forgot the New WPTY 105.3 HD3 - The World Famous WLIR!!! I live out of range and havent heard it yet. I hear its a very small signal range.

-I really wish IHeart would bring back Alternative to one of their HD outlets since it was removed from WAXQ HD2 a year or so ago.

-Why no Fox Sports Radio on a HD channel in NYC?! Wouldnt they want the 'exposure' in the #1 market? We've never had FSR here.

I have an HD radio in my car and Sangeans new HD16. I am Hoping HD will expand.In New York only 923 and 1027 are airing formats that are not on the main stations..Active Rock and Smooth Jazz. How about Standards O!dies Comedy classic soul classic country and a true light format?.Why are there so many religious stations on the subchannels? There are more than enough onthe regular channels. I really hope New York will use their HD channels better....and why is 101.1 wasting CBS Sports on two HD channels? Oldies would be ideal. Boston and Philly have some really good HD2 channels. New York is far behind.

The HD signal is much weaker than analog. I would like to be able to see HD Radio in a receiver costing less than $1000. I don't have it yet as all my receivers are working perfectly. I have a rooftop FM antenna in my attic and my signals are strong.

benale said:

I have an HD radio in my car and Sangeans new HD16. I am Hoping HD will expand.In New York only 923 and 1027 are airing formats that are not on the main stations..Active Rock and Smooth Jazz. How about Standards O!dies Comedy classic soul classic country and a true light format?.Why are there so many religious stations on the subchannels? There are more than enough onthe regular channels. I really hope New York will use their HD channels better....and why is 101.1 wasting CBS Sports on two HD channels? Oldies would be ideal. Boston and Philly have some really good HD2 channels. New York is far behind.

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Many stations are leasing out their HD channels, especially HD3 and HD4. Might as well make some $$ with them.

Some stations are using it specifically to feed a translator. I think WPLJ HD-2 is "FAS" (remembering the old WFAS-FM for Westchester County) now at 94.3.

Yes, I believe that more and more HD subchannels will be leased out, rather than run original programming. As there are apparently quite a few programmers in this area interested in leasing them, this would seem to be a case of, "Follow the money." Running original programming on the subchannels, even if it is automated, costs money. And for years to come, the audience is likely to remain too small to attract significant advertiser interest.