HD Range

[rbrucecarter5]

I found this www.distancefromto.net web site and decided to enter some HD stations.

Not very scientific - but if you leave out the temporary dropouts in the car (annoying even on full class C stations less than 20 miles away), the HD range I am getting

--- KSBJ, Houston is more than 50 miles. And they are on a short stick - only 837 feet.
--- KGLK Houston is more than 55 miles.

My stationary over the air tests in Dallas were actually at 63 miles, not the 70 I was originally thinking (the mile markers on US 75 must be wrong somehow). But still, good agreement with Houston results that at least when you are stationary and not in a null, HD coverage is amazingly good.

 

[jras20]

Before I got my new phone with Tune in, I had a HD Radio in my truck. Here at home around 30 or so miles from Austin, it dropped out a bunch, under power lines, around houses, buildings. If I was on the highway it did ok. My place out in Lavaca county, I have a HD Radio with a dipole antenna up, I can usually get Houston HD from the missouri city senior tower between 56-60db depending on the weather.

 

[rbrucecarter5]

Before I got my new phone with Tune in, I had a HD Radio in my truck. Here at home around 30 or so miles from Austin, it dropped out a bunch, under power lines, around houses, buildings. If I was on the highway it did ok. My place out in Lavaca county, I have a HD Radio with a dipole antenna up, I can usually get Houston HD from the missouri city senior tower between 56-60db depending on the weather.

Would you mind using that www.distancefromto.net site to get the exact milage to the Missouri City site from your Lavaca county location? It accepts the coordinates from radio-locator.com as-is, but for Google maps I have to add the "N" and the "W", and change the sign on one of them. Then it comes right up with the distance - the only site I found that works. I've often cited your observations when countering this movement to boost HD power. I know my own research was based on the mile marker on US 75 in Dallas and it was 6 miles off. Probably because the road isn't perfectly straight. I had been saying HD had a range of 70 miles, and it was actually 64. I doubt the cows mind either way ---- I think you said you were 84 miles out? If you could verify the number, it would really help.

Unfortunately, the HD folks ramrodded the power increase through the FCC and are now saying how great it is. But the facts speak differently. I remember in the early 70's car radios 70 mile FM stereo reception was extraordinary. But continual improvement in technology boosted that to 130 off of full class C stations. So HD range is presently pretty close to the original range of FM stereo. If HD catches on, I have faith that technical advances will boost the range without cramming more power into the sidebands.

 

[jras20]

That site I couldn't type in my exact to where my place is down there, I was able to use How far is it? By Indo.com http://www.indo.com/distance/index.html and there I was able to type in my exact location and tower location.

The Results:

84 miles (136 km) (73 nautical miles)

 

[DaveBayArea]

Not surprisingly, adjacent channel interference is a big factor in HD range. Texas is relatively flat and short-spacing is pretty much non-existent from what I have seen. The reality is that HD requires 400 KHz of occupied bandwidth and FM was built for 200 KHz. If the adjacent channel is blank the range is good. If it's not (as is our case) the range is very poor. We have no HD reception on our class B1 facility less than 6 miles from the transmitter. That's with -14dbc elevated power.

Dave B.

 

[Tom Wells]

The other big difference in where "fringe" behavior begins is the whether the market or particular station is
a "lower" antenna height with much higher actual rf power, or the big city situation where antennas are much
higer above average terrain and get supposed similar results with lower radiated power.

The latter case, where ERP is more dependent on height above terrain begins to show multipath fluttters and spits
at 20 miles. This was still acceptable but a bit annoying.

I have always been somewhat evious of the FM signals I used to hear traveling, which seemed to me much more robiust
in the fringe than what I have always experienced here in the Chicago market.

The addition of iboc sidebands makes such such dropout occurances far noiser than when simple "white nolise" was present.

 

[landtuna]

But still, good agreement with Houston results that at least when you are stationary and not in a null, HD coverage is amazingly good.

Amazingly good IF you are on flat terrain, right?

 

[rbrucecarter5]

Not surprisingly, adjacent channel interference is a big factor in HD range. Texas is relatively flat and short-spacing is pretty much non-existent from what I have seen. The reality is that HD requires 400 KHz of occupied bandwidth and FM was built for 200 KHz. If the adjacent channel is blank the range is good. If it's not (as is our case) the range is very poor. We have no HD reception on our class B1 facility less than 6 miles from the transmitter. That's with -14dbc elevated power.

Dave B.

You got my sympathy - that's awful! I've been out to the area a few times, and know how bad the glut of allocations is out there. Now you got LPFM's and AM stations wanting to get on FM translators to contend with. In other ways, I envy you because there might actually be enough stations on the air you still get oldies, smooth jazz, dance, indy rock, classical, and a whole list of other formats long since abandoned where I am.

I am still an advocate of moving the sidebands in closer to the carrier, abandoning obsolete stuff like RDS and SCA. That would narrow the bandwidth and solve a multitude of reception problems.

 

[local oscillator]

I am still an advocate of moving the sidebands in closer to the carrier, abandoning obsolete stuff like RDS and SCA. That would narrow the bandwidth and solve a multitude of reception problems.

If HD Radio were as "obsolete" as RDS, it would be wildly successful . . . which it's not.

 

[DaveBayArea]

I am still an advocate of moving the sidebands in closer to the carrier, abandoning obsolete stuff like RDS and SCA. That would narrow the bandwidth and solve a multitude of reception problems.

I was following the earlier thread on this and the trouble is that the +/- 75 KHz deviation really doesn't allow for that. If you look at the spectrum there's not much difference if you take away RDS and subcarriers. If we wanted to move FM to - say - +/- 40 KHz that could work. But then every existing radio would get quieter. Yeah, eventually IF filters would narrow, etc. But it's a can of worms.

What you suggest is actually sort of what is present with FMExtra. But we've discussed that before.

BTW - if you want a good example of what HD radio interference sounds like on FM in the foothills, I took a video of it while driving through Auburn - the largest city within KVMR's protected contour.

http://www.youtube.com/watch?v=yLTWihy5zvc

Dave B.

 

[tomservo]

Yeah, RDS is in use pretty much worldwide (except Japan, where they're oddly stuck in the 20th century radio-wise.)

I think there's a Google Labs feature you can enable on their maps to also get distances from point A to point B and beyond.

I get about 60 miles maximum reception out of the Mobile & Pensacola HD stations, the few that are left. That's about 30 miles further than I get with good stereo separation in analog.

 

[jras20]

The way the FCC works now with translators, LPFM's I doubt HD will really make a different's even at full power. Austin has so many translators it's getting harder and harder to get San antonio, HD for that mater.

 

[spt87]

The FCC is just following the same path with FM that they followed with AM. Technical considerations get overruled by political; keep jamming in more stations until it stops working correctly.

 

[local oscillator]

spt87, you hit the nail on the head; politicians are absolutely capable of defying the laws of physics -- just ask them!

 

[mgpt6]

CBS ,CC and Disney are the only ones trying to keep AM IBOC alive. Other groups have turned it off. FCC showed dump AM IBOC, and Ibuquity should lower fees for FM.

 

[tomservo]

Clear Channel seems to be cooling on HD in the Mobile market. I get the impression they've done a power increase on heritage country WKSJ, but the HD audio on the main channel sounds horrendous. Worse than the HD-2. They've dropped HD on the classic rock and soft AC stations, leaving suburbanites like me without any way to hear their news/talk AM, which disappears under Cuba from the afternoons onward.

In Pensacola, active rock TK-101 has HD and the subchannel offers an alternative rock feed, but it sounds sub-AM radio quality. Sounds like 5 kHz audio, mono. CHR Hit Music Now is actually the most reliable HD, despite being the most troubled signal that no one can pick up. It runs smooth jazz on the HD-2 now after losing ESPN to a local AM.

If they're not going to do it right, why bother at all? Just finish turning them all off.

 

[rbrucecarter5]

Just went out to 60 miles without a problem --- 107.5 in Houston. I thought about going down the road until it dropped, but I'm in the middle of Christmas shopping.

 

[KyleSmith1988]

I can hear most Charlotte NC and Greenville SC HD stations from my location here in Gaffney SC.
Each of these signals are between 30-60 miles away, and dropouts are rare.

WLFJ 89.3, WESC 92.5, WFBC 93.7, WHQC 96.1, WKKT 96.9 (hard to get HD lock sometimes),
WPEG 97.9, WSPA 98.9, WBT 99.3, WSSL 100.5, WBAV 101.9, WMYI 102.5, WLKO 102.9, WOSF 105.3,
WMIT 106.9 (HD easily goes about 70 miles), WJMZ 107.3 (hard to get HD lock sometimes), WLNK 107.9.

I've also gotten brief HD locks from WEND & WCOS which are both 75 miles away.
I also got an RBDS readout recently from WLTR in Columbia right under the 91.1 WYFG here in Gaffney.

My HD Radio of choice is an Insignia NS-HDRAD and it works great.
I also have an Insignia NS-BHDIP01 but the reception isn't as good overall, and I have a hard time hearing most of the
HD stations I listed (only WSPA 98.9 does well on that one). Our Scion xD also has an Alpine HD reciever that is flawless around here.

 

[iyiyi]

I can hear most Charlotte NC and Greenville SC HD stations from my location here in Gaffney SC.
Each of these signals are between 30-60 miles away, and dropouts are rare.

WLFJ 89.3, WESC 92.5, WFBC 93.7, WHQC 96.1, WKKT 96.9 (hard to get HD lock sometimes),
WPEG 97.9, WSPA 98.9, WBT 99.3, WSSL 100.5, WBAV 101.9, WMYI 102.5, WLKO 102.9, WOSF 105.3,
WMIT 106.9 (HD easily goes about 70 miles), WJMZ 107.3 (hard to get HD lock sometimes), WLNK 107.9.

I've also gotten brief HD locks from WEND & WCOS which are both 75 miles away.
I also got an RBDS readout recently from WLTR in Columbia right under the 91.1 WYFG here in Gaffney.

My HD Radio of choice is an Insignia NS-HDRAD and it works great.
I also have an Insignia NS-BHDIP01 but the reception isn't as good overall, and I have a hard time hearing most of the
HD stations I listed (only WSPA 98.9 does well on that one). Our Scion xD also has an Alpine HD reciever that is flawless around here.

Please keep an ear on 1660 WBCN and let us know what they are up to! It is widely believed that station will be testing pure digital broadcasting.

Thanks!

-

 

[ngriffin]

Heard digital hash on 1660 today from Taylors, SC (east of Greenville, SC). I heard no analog audio. Forgot to check at home in Spartanburg (30 miles closer).