An Affordable HD Radio

[PocketRadio]

PocketRadio=an informed consumer. Who never consumes anything. Especially the technology he claims to evaluate.

Knowledge=experience + intellectual honesty + an open mind. Remove any element of the equation, and there is no knowledge. Only hot air.

Yea, I had my fill at an electonics store !

 

[OKCRadioGuy]

I picked up one of these units at the NAB and looked at it. It didn't have a power cord attached (some multi-pin POS connector and no supply in the two booths I saw it at). I obvioulsy can't evaluate how well the thing works, but what I CAN tell you is it looks cheap and flimsy. Quite frankly I think the Sangean seperate component tuner HDT-1 http://www.sangean.com/product.php?model=HDT-1 , which I own, is a MUCH better choice, even if you have to hang an amp on the end of it to listen at your desk, etc. It's 200 bucks, and well worth it all around.

 

[radiopilot]

Radiopilot, we're talking about receiving more than mono fm, which is robust enough it works pretty well with just the power cord antenna. Try it for clean analog stereo outside of, say twenty miles, and it's "hiss city", or if there's no hiss, it's because your radio is BLENDING TO MONO. The power cord is adequate ONLY because the radio is mono.

BOTH stereo fm, AND HD require something a little better. A rotatable whip is usually sufficient for clean reception of analog stereo or HD to say 40 miles (your mileage may vary. Obviously in hilly terrain it'll be worse, in flat terrain better), say 'wabbit ears' for 60-70 miles, and an outdoor antenna and rotor can take it to perhaps 90-110 miles for either analog stereo or rabbit ears.

The idea that nobody will put up an outdoor antenna ignores one simple fact...the outdoor antenna market is BOOMING (the first time there's been growth in perhaps three decades) BECAUSE OF HDTV. Once the antenna is up, all that's required is also hooking it to your radio for superb reception. There is nothing exceptional about any of this. The requirements for clean analog fm stereo and hd are identical...something a little better than the power cord. But in city areas, where perhaps 60 percent of the population lives, even the power cord should do. The biggest limitation, and the primary reason for physically separating antenna from radio isn't that HD is somehow "defective" or "weak"...it's that HD radios are COMPUTERS, with CPUs and lots of RF floating around inside. The antenna, ANY antenna, needs to be separated from the unit by a couple of feet so that rf generated by the radio doesn't swamp the HD information. This is solvable (by manufacturers) simply by increasing internal rf shielding.

Even power cord antennas on mono clock radios NEED PROPER ALIGNMENT...they need to be run straight, no kinks or curls. EVERY radio needs proper antenna orientation. Clock radios perform quite poorly if the power cord antenna isn't run STRAIGHT. Often moving it makes a HUGE difference. HD really isn't any more fussy than that. Place the antenna, and orient it for best reception.

People aren't nearly as "antenna stupid" as you may believe. I grew up in an era, and at a location (rural NC) where ALL tv and radio reception was over the air. So did millions of people. We're used to twiddling with antennas to bring in a better signal. My 72 year old mother was listening to the radio in her hospital room the other day. It was noisy. She rotated the whip antenna until it sounded better. She is the LEAST technically knowledgable person I know, and this was a no-brainer to her. A NON ISSUE, and a waste of good time discussing it!

Maybe I misquoted, what I was referring to was a single conductor wire antenna dangling off the back of the unit, the unit above has a telescoping whip antenna and would help it some... most clock radios do not have this telescoping whip antenna, at least not the ones I've seen at most retail stores... now if they happen to be 'boomboxes' then yes they all have the telescoping whips for FM.

Most people spending thousands of dollars are using either cable or some sort of satelite system for their hish end HDTV's and I assume they aren't dangling antennas off their roofs for 'over the air' reception, unless they are hard core diehards for local TV... and most cable channels already have these local channels...

If the internal antennas affect the computer chips due to RF interference, how is it possible to blend such antennas into portable units in the future, as they try to pack smaller units to compete with satelite and now WIFI portables already spreading into the market? RF shielding to what extent?

Radiopilot

 

[R.F. Burns]

Radiopilot, we're talking about receiving more than mono fm, which is robust enough it works pretty well with just the power cord antenna. Try it for clean analog stereo outside of, say twenty miles, and it's "hiss city", or if there's no hiss, it's because your radio is BLENDING TO MONO. The power cord is adequate ONLY because the radio is mono.

BOTH stereo fm, AND HD require something a little better. A rotatable whip is usually sufficient for clean reception of analog stereo or HD to say 40 miles (your mileage may vary. Obviously in hilly terrain it'll be worse, in flat terrain better), say 'wabbit ears' for 60-70 miles, and an outdoor antenna and rotor can take it to perhaps 90-110 miles for either analog stereo or rabbit ears.

The idea that nobody will put up an outdoor antenna ignores one simple fact...the outdoor antenna market is BOOMING (the first time there's been growth in perhaps three decades) BECAUSE OF HDTV. Once the antenna is up, all that's required is also hooking it to your radio for superb reception. There is nothing exceptional about any of this. The requirements for clean analog fm stereo and hd are identical...something a little better than the power cord. But in city areas, where perhaps 60 percent of the population lives, even the power cord should do. The biggest limitation, and the primary reason for physically separating antenna from radio isn't that HD is somehow "defective" or "weak"...it's that HD radios are COMPUTERS, with CPUs and lots of RF floating around inside. The antenna, ANY antenna, needs to be separated from the unit by a couple of feet so that rf generated by the radio doesn't swamp the HD information. This is solvable (by manufacturers) simply by increasing internal rf shielding.

Even power cord antennas on mono clock radios NEED PROPER ALIGNMENT...they need to be run straight, no kinks or curls. EVERY radio needs proper antenna orientation. Clock radios perform quite poorly if the power cord antenna isn't run STRAIGHT. Often moving it makes a HUGE difference. HD really isn't any more fussy than that. Place the antenna, and orient it for best reception.

People aren't nearly as "antenna stupid" as you may believe. I grew up in an era, and at a location (rural NC) where ALL tv and radio reception was over the air. So did millions of people. We're used to twiddling with antennas to bring in a better signal. My 72 year old mother was listening to the radio in her hospital room the other day. It was noisy. She rotated the whip antenna until it sounded better. She is the LEAST technically knowledgable person I know, and this was a no-brainer to her. A NON ISSUE, and a waste of good time discussing it!

Maybe I misquoted, what I was referring to was a single conductor wire antenna dangling off the back of the unit, the unit above has a telescoping whip antenna and would help it some... most clock radios do not have this telescoping whip antenna, at least not the ones I've seen at most retail stores... now if they happen to be 'boomboxes' then yes they all have the telescoping whips for FM.

Most people spending thousands of dollars are using either cable or some sort of satelite system for their hish end HDTV's and I assume they aren't dangling antennas off their roofs for 'over the air' reception, unless they are hard core diehards for local TV... and most cable channels already have these local channels...

If the internal antennas affect the computer chips due to RF interference, how is it possible to blend such antennas into portable units in the future, as they try to pack smaller units to compete with satelite and now WIFI portables already spreading into the market? RF shielding to what extent?

Radiopilot

OK, I have DirecTV and a TV antenna because weather outages occur with both DirecTV and Dish Network. These outages can last from a few minutes to nearly half an hour. Also, someone has to set up the satellite dish on the roof. It has to be aimed at the bird and that's a azmuth and elevation settiing which is far more critical then TV antenna alignment. You guys have to come up with more reasonable arguments, if you want to continue this debate. I can see your next argument will be that Martians are employed to do the alignment on these radios and so they won't work in our atmosphere. Rediculous? You bet, would I be surprised to read it in the future? Nope. Satellite radio provides no local information or programing and there's a monthly charge for the service on top of it. Wi-Fi? Where are the car receivers? Were's the infrastructure? By the way most of the truly successful internet stations are also rebroadcasts of current terrestrial broadcasters. What I do find curious is that so much of the terminology that Leonard Kahn uses on his website is used here by the anti IBOC crowd. Check out the Wrath Of Kahn and look for the words Cartel, and then there's this line;

"To be specific, under existing Law 47 CFR Section 73.44(b), emissions 20 kHz to 30 kHz from a carrier MUST be at least 35 db below a stations unmodulated carrier."

I posted an audio sample of WRKL as received on a Sony Walkman which was recorded betwen 12 & 15 miles from their transmitter, within their protected contour and there is NO audible trace of WCBS.

Listen for yourself;

http://download.yousendit.com/1FF9F178719AB6A5

From 1:40 to the conclusion at 2 minutes is WRKL's audio. You tell me where you can hear any IBOC interference. There is none and this recording was done yesterday afternoon between 3 & 4 PM Eastern daylight time, while WCBS was running their IBOC exciter. WRKL at 910 is 30 KHZ from 50 KW WCBS AM. Kahn is as desperate as the anti IBOC group posting in here appear to be.

 

[Tom Wells]

"To be specific, under existing Law 47 CFR Section 73.44(b), emissions 20 kHz to 30 kHz from a carrier MUST be at least 35 db below a stations unmodulated carrier."

I posted an audio sample of WRKL as received on a Sony Walkman which was recorded betwen 12 & 15 miles from their transmitter, within their protected contour and there is NO audible trace of WCBS.

Listen for yourself;

http://download.yousendit.com/1FF9F178719AB6A5

From 1:40 to the conclusion at 2 minutes is WRKL's audio. You tell me where you can hear any IBOC interference. There is none and this recording was done yesterday afternoon between 3 & 4 PM Eastern daylight time, while WCBS was running their IBOC exciter. WRKL at 910 is 30 KHZ from 50 KW WCBS AM. Kahn is as desperate as the anti IBOC group posting in here appear to be.

When we say, '"to be specific", we sometimes are employing distraction.
Do not lose sight of the fact that full power into an umodulated carrier make a great big quiet spot on the dial, at a defined "spot".
Any frequencies not at even 10 khz steps are information of one kind or another.

The various multiple slow speed data streams are in fact probably exactly at the defined power level, measured by test equipment.
However, when demodulated in the presence of the host AM carrier, the -35 db product is a much louder analog noise than
ibiquity ever imagined. How can this be? The nature of loudness, and the decibel scale we use, is logarithmic.

This is why the noise level from the hiss rises so quickly when an analog AM is not critically center-tuned.
There really IS a loud hissing to either side, and now an analog radio user must tune 10 times more critically to avoid noise.
It is evidence that digital modulation is like splashing one's canoe paddle at the water, instead of applying a smooth, even pull.
Which method imparts more motion? Which method disturbs the medium wastefully?


I agree that I do not hear hiss of WCBS in WRKL's audio in your recordings, nor did I in person last week.
I do not beleive WRKL has a case.
I can easily hear with just the laptop speakers the characteristic iboc whirr/hiss, which I hear separately from the whine
intermod from the recorder which you mention.

I could clean this recording of hiss as well as the previous one, and the IBOCs would be sharper and clearer, and so would WRKL.
But I think you are suggesting these analog recordings have no hiss. Is this correct?

So far, I agree that none of the HD radios' physical design appeal to my tastes.

As far as receiver design, the only way I see to get sensitivity and keep all the digital whiz-bangs is to remote the superhet
conversion, just as LNA in sat dishes sit right there in the dish. Get the signal down to 455 khz and bring it in on a mini-coax.
Then we won't have a radio inside a computer. There is no way to adequately shield one from the other, when AM is concerned.

 

[R.F. Burns]

"To be specific, under existing Law 47 CFR Section 73.44(b), emissions 20 kHz to 30 kHz from a carrier MUST be at least 35 db below a stations unmodulated carrier."

I posted an audio sample of WRKL as received on a Sony Walkman which was recorded betwen 12 & 15 miles from their transmitter, within their protected contour and there is NO audible trace of WCBS.

Listen for yourself;

http://download.yousendit.com/1FF9F178719AB6A5

From 1:40 to the conclusion at 2 minutes is WRKL's audio. You tell me where you can hear any IBOC interference. There is none and this recording was done yesterday afternoon between 3 & 4 PM Eastern daylight time, while WCBS was running their IBOC exciter. WRKL at 910 is 30 KHZ from 50 KW WCBS AM. Kahn is as desperate as the anti IBOC group posting in here appear to be.

When we say, '"to be specific", we sometimes are employing distraction.
Do not lose sight of the fact that full power into an umodulated carrier make a great big quiet spot on the dial, at a defined "spot".
Any frequencies not at even 10 khz steps are information of one kind or another.

The various multiple slow speed data streams are in fact probably exactly at the defined power level, measured by test equipment.
However, when demodulated in the presence of the host AM carrier, the -35 db product is a much louder analog noise than
ibiquity ever imagined. How can this be? The nature of loudness, and the decibel scale we use, is logarithmic.

This is why the noise level from the hiss rises so quickly when an analog AM is not critically center-tuned.
There really IS a loud hissing to either side, and now an analog radio user must tune 10 times more critically to avoid noise.
It is evidence that digital modulation is like splashing one's canoe paddle at the water, instead of applying a smooth, even pull.
Which method imparts more motion? Which method disturbs the medium wastefully?


I agree that I do not hear hiss of WCBS in WRKL's audio in your recordings, nor did I in person last week.
I do not beleive WRKL has a case.
I can easily hear with just the laptop speakers the characteristic iboc whirr/hiss, which I hear separately from the whine
intermod from the recorder which you mention.

I could clean this recording of hiss as well as the previous one, and the IBOCs would be sharper and clearer, and so would WRKL.
But I think you are suggesting these analog recordings have no hiss. Is this correct?

So far, I agree that none of the HD radios' physical design appeal to my tastes.

As far as receiver design, the only way I see to get sensitivity and keep all the digital whiz-bangs is to remote the superhet
conversion, just as LNA in sat dishes sit right there in the dish. Get the signal down to 455 khz and bring it in on a mini-coax.
Then we won't have a radio inside a computer. There is no way to adequately shield one from the other, when AM is concerned.

In the WFAN, WABC & WCBS recordings you can hear computer interference in the form of whistling and background noise. It's not there when the computer isn't running. Which version of Nero do you have? I have Nero and it's a good software for burning CD's but it isn't a professional audio program. Sound Forge which I use is. It uses DirectX plugins and is not intended for home use. What kind of noise reduction are you talking about? If it's the type that is in my Nero 6.xx it's noise reduction isn't very sophisticated and actually ads its own color to the file. Which sound card are you using? All of these things come into play when preparing a demonstration exibit. My recordings are clean directly from the radio to the hard drive. The only changes made were in the transfer from wav to a WMA file. I live in NY, belong to our local SBE chapter 15 and from no one have I heard any complaints about any of our local stations which run IBOC causing any interference eityher to themselves or to other stations. If you follow the Arbitrons you'll see that since the installation of IBOC the ratings for these stations has remained the same. If their audio was so disturbing people would tune out en mass. It's not happening here and if we are to believe Mr. Kahn who insists IBOC interferes within a stations locval contour 30 KC from their center carrier, where is the interference on WRKL. How about WNYC? It's 50 Khz from WABC or WNYH on 740. It's 30 Khz from both WOR & WABC and yet, there is no interference. They did accuse WOR of causing interference but when pressed technically to prove the interference, they dropped their charges, especially after the FCC feild agent gave WOR a clean bill of health concerning this issue.

 

[Mike Walker]

Reading a post before commenting on it is a pretty good practice. As for how it'll be possible to have antennas in portable units, the answer (of course) is rf shielding. A PC can wreak havoc on radio reception (analog or digital). But put the PC in a Faraday Cage, and then you can get the radio very close with no noise. The shielding blocks the noise.

Portable units will undoubtedly use a composite material, composed mainly of unobtanium, to shield radio components from the antenna. Or they could use a really high-tech solution...wrap the radio's "innards" in aluminum foil. Problem solved!

You guys really are grasping at straws. "The sky is falling, the sky is falling! There can never be a sub 200 dollar radio". Now there are several. "HD is DOA...no new stations or radios". There were probably a half-dozen new radios announced in the last month, and there are new stations every day. "There can never be a hundred dollar radio". Well there ARE hundred dollar radios. Now it's "the price can't go any lower", and "you can't make a portable because you can't put an antenna in an HD radio". Yeah? JUST WATCH!

 

[radiopilot]

Reading a post before commenting on it is a pretty good practice. As for how it'll be possible to have antennas in portable units, the answer (of course) is rf shielding. A PC can wreak havoc on radio reception (analog or digital). But put the PC in a Faraday Cage, and then you can get the radio very close with no noise. The shielding blocks the noise.

Portable units will undoubtedly use a composite material, composed mainly of unobtanium, to shield radio components from the antenna. Or they could use a really high-tech solution...wrap the radio's "innards" in aluminum foil. Problem solved!

You guys really are grasping at straws. "The sky is falling, the sky is falling! There can never be a sub 200 dollar radio". Now there are several. "HD is DOA...no new stations or radios". There were probably a half-dozen new radios announced in the last month, and there are new stations every day. "There can never be a hundred dollar radio". Well there ARE hundred dollar radios. Now it's "the price can't go any lower", and "you can't make a portable because you can't put an antenna in an HD radio". Yeah? JUST WATCH!

OK.... I'll be on the look out for one of these portable units under $50.00 by the end of this year... if they introduce one similar in size to an Ipod first generation unit... I promise I will buy one, just for curiosity and report about my purchase here...

Then we'll see if HD lives up to it's promise.

Radiopilot

 

[PocketRadio]

Reading a post before commenting on it is a pretty good practice. As for how it'll be possible to have antennas in portable units, the answer (of course) is rf shielding. A PC can wreak havoc on radio reception (analog or digital). But put the PC in a Faraday Cage, and then you can get the radio very close with no noise. The shielding blocks the noise.

Portable units will undoubtedly use a composite material, composed mainly of unobtanium, to shield radio components from the antenna. Or they could use a really high-tech solution...wrap the radio's "innards" in aluminum foil. Problem solved!

You guys really are grasping at straws. "The sky is falling, the sky is falling! There can never be a sub 200 dollar radio". Now there are several. "HD is DOA...no new stations or radios". There were probably a half-dozen new radios announced in the last month, and there are new stations every day. "There can never be a hundred dollar radio". Well there ARE hundred dollar radios. Now it's "the price can't go any lower", and "you can't make a portable because you can't put an antenna in an HD radio". Yeah? JUST WATCH!

"Are you waiting in line for your HD radio?"

"If you lower the price enough, folks will buy the radio. That's the belief about HD radio that is being stoked in our industry. And, of course, it's wrong... The more you have to drop your price, the lower the chance people value what you're selling. And the less likely you are to sell your wares at any price the maker of those wares finds appealing. No matter if you're selling HD radios or satellite radios or whatever."

http://www.hear2.com/2006/11/are_you_waiting.html

Table-top HD radios require AM-loop and FM dipole antennas - portable units will need something equivalent, plus they will have to be battery-friendly. As Ramsey pointed out, the price of HD radios is a moot-point, if consumers do not see benefits to HD Radio, which so far, they have not - this is reflected in the lack of consumer traffic to these two go-to sites:

http://www.statsaholic.com/hdradio.com
http://www.statsaholic.com/radiosophy.com

 

[Mike Walker]

There are three types of AM antennas in common use. Ferrite rods, loops, and long-wires. Also in use, but less common (outside of car radios) are whip antennas (used for fm on home and portable units, but also used for am on car radios). FM antenna types include monopoles (which include whips, and power cord antennas), dipoles (including "t" antennas...but also certain outdoor types, and indoor "wabbit ears), and multi-element "yagi"-type antennas. That's it. These types may ALL be used for either analog or digital.

Other than amplifier noise from poorly designed amplified antennas, there is NO difference between antenna types for digital and analog radio within the FM and AM bands. Appropriate antenna type is determined by the wavelength of the received signal, NOT the modulation type! A little reading on antennas might aid some here in actually understanding the subject BEFORE passing judgement.

 

[PocketRadio]

There are three types of AM antennas in common use. Ferrite rods, loops, and long-wires. Also in use, but less common (outside of car radios) are whip antennas (used for fm on home and portable units, but also used for am on car radios). FM antenna types include monopoles (which include whips, and power cord antennas), dipoles (including "t" antennas...but also certain outdoor types, and indoor "wabbit ears), and multi-element "yagi"-type antennas. That's it. These types may ALL be used for either analog or digital.

Other than amplifier noise from poorly designed amplified antennas, there is NO difference between antenna types for digital and analog radio within the FM and AM bands. Appropriate antenna type is determined by the wavelength of the received signal, NOT the modulation type! A little reading on antennas might aid some here in actually understanding the subject BEFORE passing judgement.

"wabbit ears" ?

 

[PocketRadio]

There are three types of AM antennas in common use. Ferrite rods, loops, and long-wires. Also in use, but less common (outside of car radios) are whip antennas (used for fm on home and portable units, but also used for am on car radios). FM antenna types include monopoles (which include whips, and power cord antennas), dipoles (including "t" antennas...but also certain outdoor types, and indoor "wabbit ears), and multi-element "yagi"-type antennas. That's it. These types may ALL be used for either analog or digital.

Other than amplifier noise from poorly designed amplified antennas, there is NO difference between antenna types for digital and analog radio within the FM and AM bands. Appropriate antenna type is determined by the wavelength of the received signal, NOT the modulation type! A little reading on antennas might aid some here in actually understanding the subject BEFORE passing judgement.

http://www.radiointel.com/review-sonys10mk2.htm

See, they used an AM-loop antenna to increase the range of the Sony - I guess, users of portable HD, if that ever happens, can walk around with hand-held antennas. Hey, maybe some radio equipment manufacturers will figure out ergonomically-correct AM-loop and FM-dipole antennas for portable HD radio users !

 

[Mike Walker]

Again, if people here bothere do read a little about antennas they might realize that loops are not by design any more efficient than ferrite rods. They're just simpler...a few turns of wire around a plastic frame. My 1950s Zenith table radio has a loop antenna mounted to the back of the cabinet...as do MANY radios through the years. But the BEST of the old Zeniths, the Trans-Oceanics for instance, had a "Wave Magnet"...an EXTERNAL LOOP that could be moved close to a window, for instance, for better reception. Mine even has rubber suction cups so it can be stuck to a window. With antennas, few things are actually new.

My dad used to say "a little knowledge is a dangerous thing." Scary, because some who participate here posess little enough knowledge to be positively leathal!

 

[PocketRadio]

Again, if people here bothere do read a little about antennas they might realize that loops are not by design any more efficient than ferrite rods.

"Modify that AM antenna"

"Take a closer look at the ferrite bar antenna. The coil is actually a loop antenna!... So far, so good. The rules haven't changed, loops work the same way they always did. By now, you have guessed that the reason your ferrite bar antenna doesn't work very well is the size of the loop... First of all, the larger the cross sectional area of the loop, the more the gain, and the better the reception. conversely, the smaller the loop, the worse the reception. But - not just any loop will work. A loop must be constructed with an inductance that will resonate with the tuning capacitor inside the radio, and the resonant frequency range must correspond with the AM band of frequencies."

http://www.hard-core-dx.com/nordicdx/antenna/loop/amloop.html

Gosh Mike, didn't you know that ferrite-bar antennas are a form of loop antennas, and that loop antennas provide added gain ? No wonder, HD radios require external AM loop and dipole antennas.

 

[Mike Walker]

Loop antennas provide "added gain" compared to what? Ferrite rod antennas can provide just as much gain as loops. It's why high performance dx radios like the CCRadio, and GE SuperRadio series use HUGE ferrite bar antennas...much larger than those in more typical radios.

"Loops" have just a few turns of wire (usually), and NO ferrite core. Ferrite antennas have many...often hundreds or even thousands of turns, wrapped around a ferrite core. If that's the same antenna, then I'm Abraham Lincoln. Oh wait...I see your point. They're EXACTLY the same. Except for the (obvious) differences. Duh!

 

[PocketRadio]

Loop antennas provide "added gain" compared to what ?

Compared to internal ferrite-bar antennas, that are standard on most analog radios - no need for external AM-loop antennas, as on HD radios.

 

[R.F. Burns]

Loop antennas provide "added gain" compared to what ?

Compared to internal ferrite-bar antennas, that are standard on most analog radios - no need for external AM-loop antennas, as on HD radios.

And my radio doesn't need earphones like my I-pod does. I guess that's another failed technology.