The promised NYC HD (and non HD) demo.

[R.F. Burns]

http://www.yousendit.com/transfer.php?action=download&ufid=F442CD8C070AA9A9


Here’s the HD demo I promised. It starts with WFAN in HD at 00 seconds, second at 00:26 is WADS, which is 72 miles away from my house and runs 3200 watts. It’s third adjacent to WFAN and second Adjacent to WOR both of which are running their HD exciters and I am in a null of WADS. WOR follows next at 00:44 after which is WABC at 2:16. WCBS 880 is next at 3:03 into the file. We switch to FM for some demos, first WNYC HD 1, 2 & 3 at 4:01, 4:27 & 514 respectively. Then we listen to WPLJ HD 1, 2 & 3 at 5:47, 6:08 & 6:43. The next demo was recorded from a super radio placed approx 2 feet from my HD radio. First we hear WRKL, 1 KF and 3rd adjacent to WCBS. It starts at 7:25, next is WCBS at 7:31 then WABC at 7:42 and WNYH at 7:43 which is 740 located about 50 miles from me and between two HD stations at 7:10 and 740 KHz. Then WOR at 8:05 and lastly WFAN at 8:29. We go back to the Sangean for WAWZ which is 60 miles from me at 9:30 into the file. Next is WHCR at 10:11 which was a bit noisy this morning at 90.3 MHz. They run 8 watts and are 25 miles south of me. Followed at 10:55 by a WKTU HD 2 ID and finally at 11:11 is WKXW in Trenton which is 90 miles south of my location. I posted the file in WMA format at 128 Kbps. Hope this gives some insight into what HD sounds like in the NY metro area.

 

[calstymes]

Well R.F., I must say that you have some very fine receiving equipment! HD on that Sangean sounds superb and the Super Radio is no sloutch either.

I'm going to have to go out and get a Sangean soon! I want my HD Radio!

Now how would you like to buy two BA's (cheep!) that can't hear worth a darn? Just think, you might be able to use your vast experience in the broadcast industry to fix them and then you could sell them back to me! Whad'ya think?

All kidding aside though, overall your air checks sound excellent, and I think that you are very lucky to have as excellent a listening location as you do. You have been saying for many months and all along that you have no problems listening from there, and by golly, you're right! I wish I had as good a listening location. Maybe someday I'll be able to move to the suburbs too!

 

[R.F. Burns]

Well R.F., I must say that you have some very fine receiving equipment! HD on that Sangean sounds superb and the Super Radio is no sloutch either.

I'm going to have to go out and get a Sangean soon! I want my HD Radio!

Now how would you like to buy two BA's (cheep!) that can't hear worth a darn? Just think, you might be able to use your vast experience in the broadcast industry to fix them and then you could sell them back to me! Whad'ya think?

All kidding aside though, overall your air checks sound excellent, and I think that you are very lucky to have as excellent a listening location as you do. You have been saying for many months and all along that you have no problems listening from there, and by golly, you're right! I wish I had as good a listening location. Maybe someday I'll be able to move to the suburbs too!

Cal, all I can say is thank you for being fair about all this. The Sangean is an amazing radio. I must have earased my WSIA ID. It's an 11 watt stereo college station on Staten Isand on 88.9 Mhz. My B.A. is a good one. One of the few I'm afraid. The problem which many of these HD radios suffer from is poor shielding. Internal interference within the radios make them seem insensitive. As to my location, I'm not on a hill or anything special. It's really all the radio. The Sangean tuner is spectacular. I have the one with the software which will decode C-Quam although it isn't as good with that as my Sony AM stereo radios are. It takes more signal to open up the Sangeans decoder. I still think the AM's have too many artifacts i my opinion, but it's a work in progress and time will resolve the issues I hope. Unfortunately WAWZ had their HD 2 channel off today. DOn't know why but as you can tell by listening. For a station from central NJ its HD is pretty solid. I'm using a TV antenna located in my attic which also feeds 3 TV's. It acts as a backup for my DirecTV service. Anyway,m thanks again Cal. I appreciate the kind words.

 

[Chuck]

I’ll give credit where credit is due. I’m impressed. It confirms my belief that the Sangean tuner is an exceptional piece of equipment. I'm not sure that everyone is going to have the same result, but it gives reason to be optimistic.

I also have to agree that your GE Super Radio works quite well too. I’ve had very good results with them too. They are a real bargain in the world of consumer radios.

I'm curious though. You say WHCR is 8 watts 25 miles away from you? They must have an incredibly good antenna position and a very clear channel to broadcast on to do that. Are they on the Empire State Building? Just wondering…

 

[SUPERCASTER]

R. F. Burns said:

The problem which many of these HD radios suffer from is poor shielding. Internal interference within the radios make them seem insensitive.

I thought the whole point of HD Radio was that HD digital radio was to offer robust reception even at lower power, and interference immunity. Now it turns out that HD digital radio is much more fragile, limited range, much more susceptible to interference, needs external antennas, and is more finicky then analog FM. So why bother with HD radio?

Since there is a better, truly on channel, system, FMeXtra (www.dreinc.com) FM HD radio no longer has any reason for HD's added adjacent channel interference or even it's continued existence.

 

[R.F. Burns]

Actually Chuck, I can't receive WHCR with any other radio I own, including the Super Radio and my regular tuner, a Sansui TU 717. I was attempting to demonstrate how sensitive the Sangean is. To be fair because my antenna is directional it nulls out a stronger Long Island station which I receive in my car. In my car I can hear WHCR abour 5 miles from their transmitter site. They are on the very crowded non commercial FM band. Their antenna is in Harlem at only 166 foot above ground. Unfortunately I erased my WSIA demo. I can't receive that station even in midtown Manhattan with my car radio. They run 11 watts and are abour 50 miles away. If further proof is needed I can record that station as well and post a demo. Thanks to DSP at times I can also receive WPUR at 107.3 which is located between 2 locals and is 140 or more miles away. It's weak but I can get an ID.

 

[R.F. Burns]

R. F. Burns said:

The problem which many of these HD radios suffer from is poor shielding. Internal interference within the radios make them seem insensitive.

I thought the whole point of HD Radio was that HD digital radio was to offer robust reception even at lower power, and interference immunity. Now it turns out that HD digital radio is much more fragile, limited range, much more susceptible to interference, needs external antennas, and is more finicky then analog FM. So why bother with HD radio?

Since there is a better, truly on channel, system, FMeXtra (www.dreinc.com) FM HD radio no longer has any reason for HD's added adjacent channel interference or even it's continued existence.

What I attempted to show was that first, AM IBOC causes no interference in my area to second of third adjacents and that you can not hear IBOC running when you're using an analogue radio. Second, a demo of FM HD 1, 2, & 3 streams and third a demo of how well the Sangean does with an extremely weak signal. I demo'd a solid HD signal from 60 miles away and a non HD commercial station (also not listenable on any other radio) from 90 miles away. I think the radio did a great job. FMXtra, from what I've been told does not stand up to multipath, which IBOC does and it will not work on AM, which IBOC does. Each system has it's pluses and minuses. What I've attempted to show is thgat IBOC isn't the demon some would have you believe. I've done so not with links but with real world audio examples, which can not be denied.

 

[R.F. Burns]

Actually Chuck, I can't receive WHCR with any other radio I own, including the Super Radio and my regular tuner, a Sansui TU 717. I was attempting to demonstrate how sensitive the Sangean is. To be fair because my antenna is directional it nulls out a stronger Long Island station which I receive in my car. In my car I can hear WHCR abour 5 miles from their transmitter site. They are on the very crowded non commercial FM band. Their antenna is in Harlem at only 166 foot above ground. Unfortunately I erased my WSIA demo. I can't receive that station even in midtown Manhattan with my car radio. They run 11 watts and are abour 50 miles away. If further proof is needed I can record that station as well and post a demo. Thanks to DSP at times I can also receive WPUR at 107.3 which is located between 2 locals and is 140 or more miles away. It's weak but I can get an ID.

I misstyped and because I don't want to be accused of anything I have to correct myself. WHCR's antenna is approx. 200 foot above ground. Sorry for the error.

 

[Mike Walker]

DAMN! Thanks RF! That's something a guy in the sticks in North Carolina just couldn't hear for himself. There are NO AM HD STATIONS ANYWHERE AROUND HERE!

You have given me hope in a couple of areas...number one, hope that I may have been wrong about the amount of interference from AM HD, and two that the codec CAN sound passable at low bitrates. Perhaps stations are just learning how to do it better, because off-air demos (of AM HD) I heard a few months ago were just AWFUL. These ain't (awful). I have hoped all along that I was wrong about AM HD. I believe now that I just MIGHT be!

WELL DONE ALL AROUND, THANKS!

 

[R.F. Burns]

R. F. Burns said:

The problem which many of these HD radios suffer from is poor shielding. Internal interference within the radios make them seem insensitive.

Sorry I didn't read yor comment properly. It's called swamping. If you sat with a very sensitive radio of just about any consumer type inside most radio stations transmitter site parking lots in the NY market (most are across the river in Jersey) you'd have problems receiving most out of market stations. First or second adjacents, Forget those too. Drive along the west side highway in Manhattan and listen to WCBS and WFAN disappear. These are two 50 KW stations which may be 10 miles by air from midtown. What's up? It's called swamping. Your receiver is filled with too much competing RF to seperate the weak from the stronger interference. The problem is that there's nothing wrong with the technology. The problem is in receiver design and manufacture. If you downloaded my files you heard WAWZ (Star 99.1) which is 60 miles from me and clear as a bell and much clearer than the analogue. The analogue of that station sounds a little better than NJ 101.5. Not a bad signal but nowhere near as clean as the HD signal. I thought at least that would convince those who claim all sorts of issues with HD radio's coverage.

 

[Chuck]

Actually Chuck, I can't receive WHCR with any other radio I own, including the Super Radio and my regular tuner, a Sansui TU 717. I was attempting to demonstrate how sensitive the Sangean is. To be fair because my antenna is directional it nulls out a stronger Long Island station which I receive in my car. In my car I can hear WHCR abour 5 miles from their transmitter site. They are on the very crowded non commercial FM band. Their antenna is in Harlem at only 166 foot above ground. Unfortunately I erased my WSIA demo. I can't receive that station even in midtown Manhattan with my car radio. They run 11 watts and are abour 50 miles away. If further proof is needed I can record that station as well and post a demo. Thanks to DSP at times I can also receive WPUR at 107.3 which is located between 2 locals and is 140 or more miles away. It's weak but I can get an ID.

I misstyped and because I don't want to be accused of anything I have to correct myself. WHCR's antenna is approx. 200 foot above ground. Sorry for the error.

Even at 200 feet, that is very impressive performance from the Sangean. It might be a better choice in some translator installations than the highly acclaimed Fanfare (which is a heck of a good radio.)

I think one of the main misgivings many of us have with HD is not how well it works with really great radios like the Sangean, but whether it plays nicely with existing radios. The fact of the matter is most consumer radios are real pieces of junk. They usually have fairly poor sensitivity and even worse selectivity. Even the GE Super Radio is far superior to the radios you will find in most people's homes. For better or worse there are millions and millions of conventional radios. It will be a very long time before they have all been relegated to the land-fill.

 

[stevenNOLA]

I finally had a chance to listen...sounds similar to my experiences. Thanks for your time to compose these audio bits.

Steven

 

[R.F. Burns]

Actually Chuck, I can't receive WHCR with any other radio I own, including the Super Radio and my regular tuner, a Sansui TU 717. I was attempting to demonstrate how sensitive the Sangean is. To be fair because my antenna is directional it nulls out a stronger Long Island station which I receive in my car. In my car I can hear WHCR abour 5 miles from their transmitter site. They are on the very crowded non commercial FM band. Their antenna is in Harlem at only 166 foot above ground. Unfortunately I erased my WSIA demo. I can't receive that station even in midtown Manhattan with my car radio. They run 11 watts and are abour 50 miles away. If further proof is needed I can record that station as well and post a demo. Thanks to DSP at times I can also receive WPUR at 107.3 which is located between 2 locals and is 140 or more miles away. It's weak but I can get an ID.

I misstyped and because I don't want to be accused of anything I have to correct myself. WHCR's antenna is approx. 200 foot above ground. Sorry for the error.

Even at 200 feet, that is very impressive performance from the Sangean. It might be a better choice in some translator installations than the highly acclaimed Fanfare (which is a heck of a good radio.)

I think one of the main misgivings many of us have with HD is not how well it works with really great radios like the Sangean, but whether it plays nicely with existing radios. The fact of the matter is most consumer radios are real pieces of junk. They usually have fairly poor sensitivity and even worse selectivity. Even the GE Super Radio is far superior to the radios you will find in most people's homes. For better or worse there are millions and millions of conventional radios. It will be a very long time before they have all been relegated to the land-fill.

Relatively speaking the Sangean especially for a tuner is not an expensive radio. It's even more of a bargain when you consider that this is a first generation item. Look at the IPODS. They're still well over $200 and my 40 GB was $400. That's a lot more expensive then my radio and yet, they're sold by the truckloads. As far as the SuperRadio goes. I find the results in the car radios I've listened to, to be similar. The advantage of the car radio is there's no tuning, due to the way any current car radio is tuned. I cvan record a demo using my old Philco wood boxed radio. The average person isn't using a old radio. Most table radios that people have, show results which are similar to those I displayed in my demo. The super radio is no real DX machine. It's a nice table radio but try doing 9 Khz splits with the super radio. I can do it with my Gilfer modified FRG 7000 communications radio and my Kenwood TS 430. Even a stock Sony SRF 2010 I own won't do LW or MW transatlantic DX in my area, like I've been able to do with the radios I described above. I have walkmen radios and none of them have any trouble with AM IBOC interference. If you have a radio which is in poor condition and operates improperly, the aswer is to replace the radio not the method of transmission. So far the only complaints I've read concerning AM and FM interference unfortunatley are from those with an agenda of their own, who create scenarios to support their arguments be they real or ficticious.

 

[EasyPeazy]

This is funny as hell. Someone finally makes a demo in the most RF congested part of the country that debunks all the interference whining you hear here and the silence from the anti-HD guys is deafening.

I guess it is hard to argue against the proof when it's right there for everyone to hear!

 

[Tom Wells]

I do not doubt the recordings at all. I have listened 5 times.
I respect your employment in the field and your extra class ticket.
Thank you for using a GE Supertuner for the analog demo, as most radio people have heard one.

I see you, too need to rock back-n-forth to find the point of minimum hiss for AMs with HD.
And when you are there, the audio is muddy to the point of unintelligibility.
Hence, I can not "just keep listening in analog", it's been shot in the foot.
These stations need to pull some of bottom end out of their audio to restore intelligibilty.

This recalls a lecture and argument at Valpo Tech in 1980. It was whether radios should be center-tuned, and whether the
discrimination against upper audio frequencies by IF bandpass was or was not frequency distortion, as a failure to reproduce
sent information is by definition frequency distortion.

The consensus was that like weeds, it's only a weed if you don't want it.
A communication receiver with a 1khz wide setting, if copying CW, is often too wide.
A broadcast service AM signal ought to go at least to 10 Khz, making it 20 wide on "events".
If a particular radio is only 10 khz wide in the IF, tuning above or below allowed reproducing the WHOLE audio spectrum, though
only from one sideband. This was also useful for avoiding splatter or noise on one or another sideband.

Radios which are center-tuned by intent or design will always suffer frequency distortion unless variable bandwidth from
3 Khz to 20 khz is provided for ME to select my listening intent.

In the demo recording, the narrow IF makes ALL the AMs sound muddy. I submit you might have found one or two signals
in analog which justified "side tuning" to display the actual high frequency material present in some AMs.

I also notice you tune VERY quickly away past the AM sidebands.

My demo has been recorded, but not yet assembled for posting to file sharing site.

I wish to show the capabilities of AM, and the degradation caused by HD.
I used a GE AM/FM repro catherdral radio from about 1983, with fairly good audio, no ceramic filter, and cheap 2-stage IF.
I have added a -60db notch for 10 khz at the speaker. Rather than record at the detector, I recorded tapped onto the voice
coil, so there's no 10 khz whistle.

All sections were recorded from this radio in AM analog. I hope to have the file posted today.

 

[Mike Walker]

The problem with tuning off center is distortion. YES, you may get more highs, but distortion rises very quickly. Better to tune to exact center, and have multiple bandwidths...ideally with sync selectable LSB and USB and/or variable passband. I hear what you're saying, though. Here in Wilkes County there's an AM station on 1240 (WWWC Wilkesboro NC). Sometimes I like to listen to another AM on 1230 about 40 miles away (WNNC Newton NC). Not an easy task! But I can do it on my Drake SW8...just use narrow bandwidth, put the Drake on 1230, then slowly tune down away in 1khz steps until the splatter from 1240 is gone...usually at about 1229khz, or 1228khz. Best audio, however, TO THESE EARS on a good, strong station, is dead-center tuned, with wide bandwidth. Need more highs? Turn up the tone/treble control!

I am dead set against AM stations rolling off lows in addition to highs. YOU'RE NARROWING THE BANDWIDTH FURTHER! Bass gives music it's foundation! Just thinking out loud, but has anyone tried using something like an Aphex Aural Exciter set to kick in at about 2khz to add extra harmonics below 5khz...restoring some intelligibility, without actually increasing bandwidth. AM analog bandwidth SHOULD go to at least 10khz on the transmission end, allowing listeners to dial in their own compromise between fidelity and noise/interference. But maybe it's time to try some other psychoacoustic tricks to make stations sound "crisper" than they really are. My 2 cents worth, yours for free.

 

[R.F. Burns]

I do not doubt the recordings at all. I have listened 5 times.
I respect your employment in the field and your extra class ticket.
Thank you for using a GE Supertuner for the analog demo, as most radio people have heard one.

I see you, too need to rock back-n-forth to find the point of minimum hiss for AMs with HD.
And when you are there, the audio is muddy to the point of unintelligibility.
Hence, I can not "just keep listening in analog", it's been shot in the foot.
These stations need to pull some of bottom end out of their audio to restore intelligibilty.

This recalls a lecture and argument at Valpo Tech in 1980. It was whether radios should be center-tuned, and whether the
discrimination against upper audio frequencies by IF bandpass was or was not frequency distortion, as a failure to reproduce
sent information is by definition frequency distortion.

The consensus was that like weeds, it's only a weed if you don't want it.
A communication receiver with a 1khz wide setting, if copying CW, is often too wide.
A broadcast service AM signal ought to go at least to 10 Khz, making it 20 wide on "events".
If a particular radio is only 10 khz wide in the IF, tuning above or below allowed reproducing the WHOLE audio spectrum, though
only from one sideband. This was also useful for avoiding splatter or noise on one or another sideband.

Radios which are center-tuned by intent or design will always suffer frequency distortion unless variable bandwidth from
3 Khz to 20 khz is provided for ME to select my listening intent.

In the demo recording, the narrow IF makes ALL the AMs sound muddy. I submit you might have found one or two signals
in analog which justified "side tuning" to display the actual high frequency material present in some AMs.

I also notice you tune VERY quickly away past the AM sidebands.

My demo has been recorded, but not yet assembled for posting to file sharing site.

I wish to show the capabilities of AM, and the degradation caused by HD.
I used a GE AM/FM repro catherdral radio from about 1983, with fairly good audio, no ceramic filter, and cheap 2-stage IF.
I have added a -60db notch for 10 khz at the speaker. Rather than record at the detector, I recorded tapped onto the voice
coil, so there's no 10 khz whistle.

All sections were recorded from this radio in AM analog. I hope to have the file posted today.

The super radio being analog and not channelized requires that a person tune for center carrier. I'll have to record some demos from my car radio which is channelized so that you can hear what HD am's sound like when tuned by a car radio. I'll have to use a microphone to make the recording in that case but that shouldn't be a major problem. As far as AM audio on the super radio is concerned. I took the headphone out jack and plugged it right into my Dat recorder (A JVC DA-40). I wasn't very carfull about the input level and you can hear the distortion on some parts of the audio. The point of the demo wasn't to show the Super radios audio but the fact that there was no IBOC interference. I will make another recording later in the week when I have a chance and make sure the tone control is no longer set flat. In my area there is no IBOC interference and only DXers care about first adjacents. I believe my demo proved what I set out to prove. A properly engineered HD station works as promised. Of curse wide band AM can sound great but you still have to deal with static which is one of the main causes of younger people tuning away from AM facilities and it's stereo with no platform motion issues. It's 21 century technology and at least in my case working well. Oh and 1 Khz is huge for CW. I use a 400Hz filter for CW. Years ago when I was much more active my CW speed was upwards up 35 wpm.For SSB we use 2.4 K filters. Today with DSP and all they can do much better as far as selectivity figures are concerned.

 

[Tom Wells]

Tuning away from center does not produce distortion >until< the passband skirt is attentuating the carrier, and allows
detecting the full audio passband, if the design is wide enough, assuming the upper and lower sidebands truly contain the
same modulation.


The HD does work as promised. As described on paper, there are multiple digital sidebands in an area we have been using to
decode audio information of high resolution, needed to distiguish language and other sounds accurately.
I could hear exactly what it was going to sound like the first time I read the description.
And it does.
The only time I would EVER tune to center is in the case of bad man-made interference.


Just like the argument back in 1980, some people felt exactly as you do, and some felt as I did.
This was a radio engineering school. Our transmitter instructor, D E Wiggins also advised us about making sure your upper and lower end limits were compatible. The lower end response is too much now for the highs left.
If you listen to AM on something with 12 inch speakers, it's too much.
The present HD from AM needs to be listened to on 4 inch speakers to have proper balance.

For fun I like to slice CW signals on a old Collins 390A. It has IF bandwidths down to 100 hz, and you can also enable a
1 kc audio-peaked filter. But even the 16 khz setting is not full AM fidelity.

The better AM stations using HD seem to give a kick to the 3-5kc sounds, which does help, but still sounds cheesy compared to
a full range signal.

 

[Mike Walker]

Well distortion does AUDIBLY increase on every AM radio I own as I tune away from center enough to perceive any increased highs. As for "12 inch" vs "4 inch" speakers...my Energy C3 speakers are flat to 30hz in my room, with just a touch of boost on the bottom two bands of my graphic eq. The Energys use 6 1/2 inch woofers. Extended bass (in speakers) is a result of more than driver size. And there's more to it than just "if you roll off highs, you need to roll off lows". I'm sorry, but in my experience engineers are damn lousy listeners (on average). I've seen them walk away saying "everything's fine" when left and right channels are out of phase, when channels are reversed on everything, when there's 10 percent distortion because the transmitter tubes should have been changed at least once since the Truman Administration!

Try some speakers with FLAT RESPONSE! EXTENDED bass doesn't mean overpowering bass! Music needs bass! Reproduced audio needs bass. It's foolish to get rid of the lows just because somebody told you you had to get rid of the highs. Does your telephone sound "balanced"? IT has no lows, OR highs!

You told me the WKSK sample had "no highs" despite the fact that my ears, and a spectrum analyzer (try one on that file!) clearly show plenty of energy in the 8-9khz range...as high as an analog AM station can LEGALLY go in 2007. Hey, if you're used to the tinny, distorted "splat" from tuning off center, then that ain't what's on the WKSK recording. What IS there is balanced, browdband AM reception that' noise free, full bodied (with bass to the "bassment"), and as "bright" as the law allows. Tune off center if you want. Thank God most radios these days are digitally tuned so it's not an option!

 

[Tom Wells]

Exactly! A telephone IS a balanced distibution of frequencies. Three hundred to three thousand hz, period.
Not a desirable frequency response, but balanced and more intelligible than AM when brickwalled at the station and center tuned for HD.

I agree that music needs bass, and simplify the "speaker size" issue in order to say there should be less bass as there is less treble.

I also know that there is a great difference in high-end response limits from station to station, and they're not complying to the same standard.

If you're hearing "splat" from side-tuning on AM, you have tuned past the carrier and are receiving sideband only.
If you then open up your bandwidth, you will find the distortion is gone.

I, too deplore engineers with no ears.
But it is worse to hear something "wrong" and pretend everything is OK to satisfy "the man".
I will not pretend everything is OK with the analog left over after HD is added.

I also keep hearing reference to "legality".
With all due respect, I think the precedent has been set by ibiquity.
Seems it's OK to put sidebands out to 20khz continuously.
So of course it's no problem to have modulation out there 2 to 3 per cent of the time....