I bought one of those Coby tuners back in the day - still have it. The issue I have is with the included power supply when on analog AM. It is a major source of the hum I had that made analog AM unlistenable. I had a Kloss / Cambridge SoundWorks clock radio with HD AM and FM and it worked very well. Only reason I got rid of it was the back-lit LCD that completely lit the bedroom even on the lowest setting. Anyone remember when Chrysler and GM both had AM stereo in cars? Sure it was analog, but the fidelity was improved.
You have the same buzzing issue that we had in our neighborhood some years back. It was explained to me by someone at the power company. Two issues. First: bad grounds in the grid. Self-explanatory, they aren't maintained like they used to be. Secondly: Electric utilities used to employ filter chokes to help keep broadcast radio relatively free from coupling noise. Here in the northeast, utilities stopped using those about 20-25 years ago to cut costs. On strong MW signals, the power grid actually captures the radio signal, and sends it into the radio via the AC line. Since the radio is receiving the same signal via an antenna at the same time, the two signals mix, and what you get is a mess of 60hz buzz, but typically only on strong stations in the lower half of the dial. Your assumption that it's coming thru the grid is correct.
It's up to maybe 5Khz on the stations that have narrowed their bandwidth to accommodate the hash generator HD radio. AM can use up to 10Khz...and there are still some AM stations that are doing just that.
+Jim zz I doubt many AM receivers would make 5k, let alone 10k. Most are tuned to a peak for sensitivity and selectivity. Saying that an old British AM tuner (QUAD) did have a switch to decrease selectivity and flatten the bandwidth, did make strong signals sound quite good.
Michael Beeny Cheap radios such as battery-powered portable radios and table radios usually actually sound better on AM because it costs money to put in extra filtering to narrow down the bandwidth, so they leave those parts out and you get wideband AM radio. If you can hear the 10 kHz (or 9 kHz in Europe & Asia) adjacent carrier whistle at night, then you know your AM tuner has audio response up to at least that high.
@@vwestlife I noticed that my old cheap Sony receiver absolutely beats my dx-radios in terms of AM sound quiality, just because it has a wide filter. And with the help of an external ferrite antenna it becomes quite sensitive as well.
You have digital radio on AM as well? That's really cool! Here in Germany there's nothing left worth listening to on AM, most of the broadcasting sites have been shut down and demolished. We have digital radio too, it's called DAB+ (Digital Audio Broadcasting) but it uses the former VHF television band and higher frequencies, so the receiption is not always easy, especially in houses. Does HD radio in the USA use the same frequency bands as the analog stations? I listened closely with good headphones. On AM the improvement is - of course - outstanding. On FM it seems like not all station are using the same bit rate (kbp/s). On some stations you can make out the typical compressed sound or "digital artifacts" on HD while the FM signal sounds almost better (this is a problem with DAB+ here in Europe as well...some stations use really low bit rates so digital radio often sounds somehow "dull" compared to FM). On other stations you tuned in I did not notice the compression and the HD signal sounded even "brighter" than FM. This might result in the fact the normal analog FM audio signal range only goes from 30Hz to approx. 15kHz. Of course it could be due to different pre-equalization to make the HD signal sound much more better than it actually is. But in certain cases HD radio is an improvement for sure, especially if the analog signal is too weak so you would have to deal with background noise.
Yes, HD radio puts the digital carriers directly adjacent on either side of the analog signal. This has the effect of making one hybrid station take up the space of three analog stations with the additional digital carriers on both sides of the analog, so you can't have any directly adjacent stations in the same market. It's made the VHF FM band much more crowded as a result. In smaller markets, HD radio is rare to nonexistent because of the frequency coordination difficulties with adjacent stations. So you really only see HD radio in big cities like LA, Chicago, NYC, etc. The plan is to shut off the analog and only use the digital at some point, but that would mean all the old radios would cease to function just like analog TVs...
The only problem I have with HD radio (in the USA) is it's the only FCC approved digital broadcast system and all HD receivers sold include a royalty fee that goes to a shell corporation whose "investors" include major media companies. So you get to pay an extra fee to hear 40 minutes of commercials an hour with a slightly better sound quality.
HD radio has now been reverse engineered and you can download and compile a free program on your computer to listen to it with a SDR. The program is called nrsc5.
HD Radio (IBOC) is better than DAB because it preserves the analog FM channel. However, FM radio stations in North America are spaced further apart, so IBOC technology works here.
Don't hold your breath. HD Radio, despite being referred to as IBOC, isn't actually on-channel. Idk enough about AM in general to comment on it, but on FM, it needs a total of 400 KHz to work. The fact that we space our FM stations 200 KHz apart helps massively (seriously, any US radio with a digital tuner, you move the knob one notch or tap the button one time, and it'll jump from, say, 97.1 straight to 97.3). So too do some old allocation rules in which stations with geographically-adjacent or overlapping (official) service areas have to be at least 400 KHz apart. Besides, HDR actually has developed a path to no-analog broadcasting in much the same vein. We already have four AM stations in the country which broadcast on the HD Radio All-Digital format - one authorized experimentally, the other three under new FCC rules from October 2020.
@@Toast0808 HD radio is not possible in many European countries because the frequency band is more crowded than in the USA. In the USA, the channel spacing is 200 kHz and in Europe 100 kHz. This would lead to a lot of interference with HD radio.
This is an excellent demonstration of HD radio. There wasn't any noticeable difference on FM with the exception of 93.9 when it went from analog to digital. The analog signal had some background white noise but when it went to HD mode, the noise was completely gone. Other than that, there was hardly no difference in the reception. AM is definitely an improvement of audio quality. I have a feeling that analog AM will soon disappear just like analog TV did because of the bandwidth and so many new wireless devices are being developed.
Funny, I was just asking you about this a few weeks ago. Great answer BTW. Man amplitude sounds GREAT here. Incredible. Good demonstration. I usually only listen to AM or broadcast for voice. Good stuff Shango. Steven
My car came with HD radio and it's great if you are in the range of a strong station. HD range is limited especially here in New England due the hills and mountains. I really get a kick out of some of the substations format wise. In Boston one station's substation is all Christmas music year round!
My guess is that the eq difference is caused by the lack of pre emphasis which allows for more highs. I notice the same thing on DAB here in euroland. The hum might be rectifier diodes mixing 60Hz with the strong MW stations.
nice demo video shane makes me want to get a hd radio but i dont hear fm stations advertising hd any more and i dont even know if any are left in the sarasota bradenton fl area
The AC adapter that came with my Coby HD Radio caused buzzing on AM. After I replaced it with a high quality power supply, the buzzing went away. Also, although mine was "new in box", the coin cell battery in the remote was dead. Most of the FM stations in LA seem to process their HD audio well, but many of the stations in NYC make their HD audio too bright and there is often an audible echo or flanging effect as the digital audio kicks in. And on 1260 KMZT you can really hear the shrill, metallic sound caused by the very low bitrate digital audio stream (36 kbps) that HD Radio uses on AM.
Alan Maier I used the power supply that came with my Directed Electronics HD Radio. It is a Ktec model KA12D120150016U with 12-volt DC output at 1500 mA.
Our Czech National station is testing broadcasting purely on digital on AM using DRM system. It is not all that bad for bout 24kbps AAC with SBR and PS. But I don't any local way to receive it.
In my area two FM stations tried HD radio for about a year, and then abandoned it. I know one of the owners and he said the radios never sold and the yearly rates he paid to license the HD broadcasting equipment wasn't worth it.
I noticed that there were no digital AM stations tuned to that broadcast in stereo. Perhaps because of certain bandwidth limitations or other technical issues? The 60-cycle hum definitely disappeared when in analog mode on the AM band.
shame we don't have HD radio here we have DAB but most stations are mono though there around 100 on there. but DAB can cover pretty good if more than one transmitter is used they have like 10 in Essex.
I suspect that much of the difference heard between analog FM vs HD has to do with the audio for these two programs going through separate processing chains. It is too much trouble to match them exactly.
It's a shame it sounds so similar. They had an opportunity to put out a clean signal in HD without compressing it to hell like regular radio. People who spend extra for HD radio are more likely to have the audio equipment and knowledge to take advantage of a high dynamic range. Then it would actually sound like real music.
The "Buzzing" exists here in Louisiana too, I think it is part of the new "smart grid" technology but that's my opinion. It is HORRIBLE on the shortwave bands as well as AMBC.. When I go to battery power though it goes away unless I get close to an AC line cord.. It also goes away when I isolate my home off the grid and go 100% solar power running through pure sine inverters... SO yeah its on the grid whatever it is.
The unfortunate truth is that HD radio isn't HD quality. Not even close. In an effort to cram as many multicast stations as possible on one signal, the quality has gone to junk due to bandwidth squandering, just like SiriusXM. In my market, the bitrates vary from 23-56 kbps (HE-AAC encoding). Even at 56 kbps (the max in my market), I can hear tons of compression artifacts in the high end with HD radio. It's so bad I've actually shut off HD radio in my car and only listen to the analog FM signals because they sound so much better. The station engineers treat HD radio like a bastard child-the EQs and volume levels are often way different between the analog and digital, so you get blasted with treble, get bass clipping on the mumble rap stations, or have to crank up or down the volume when it switches from analog to digital. The local classical music station also has their L and R channels reversed in their HD signal vs. analog. This is basic A/V stuff people. I've never heard a full 96 kbps HD radio station to see if it's acceptable or not. But that would mean only one HD station, so station managers aren't going to do that when they could have three or four multicast stations making money because who cares if they sound terrible? The other topic that bugs me is why modern AM radios only have an audio bandwidth of less than 5 kHz when the AM signals are broadcast with 10 kHz (and before that it was 15 kHz). They chose 5 kHz to eliminate the possibility of any adjacent station interference, but if there's nothing next to your favorite AM station, there's no reason why you couldn't get the full 10 kHz. As I understand, they made some AM radios with a narrow/wide switch to solve this problem, but I've personally never seen one. This oversight is going to be the death of AM radio because modern receivers with fixed 4-5 kHz bandwidth just sound too horrible for most people to tolerate before hitting the FM button.
We adopted the DAB+ broadcasting standard here in Australia and it's only being broadcast in our capital cities at present, most of the city stations are simulcasting on DAB+ and are also using AAC encoding, and although they all are using different bitrates, there's not much difference between analog FM and digital, there is, of course, a vast improvement in quality compared to analog AM and each station has it's own digital only stations, the vacant Digital TV Channels in VHF Band III are being used to broadcast DAB+ here, which, with any radio standard, has it's pros and cons.
I have several HD radios. Both FM only and some FM/AM. I've found that they use more higher end audio EQ and stereo separation. However a NON HD Radio station, WGSQ FM sounds great on FM without the digital only signal, simply better preprocessing and use of the exciter. I feel Digital does offer more in the scheme of more stations or channels in the same carrier/ssb. That's Bout it. I would prefer a HQ preprocessing analog signal on FM or AM and RDS as apposed HD Radio.
Hey Shango, if you still have this radio, take it with you the next time you go out into KYET Cactus Country territory. This model can decode C-QUAM AM-stereo. It's one of the few HD radios that can. Don't get your expectations too high with it though, they are narrow and I do believe the stereo channels will be flipped. They also like a decent signal, so it probably won't decode off weak DX.
Vynncent Murphy I know this is a little late, but a much better radio than this Coby one is the Insignia NS-HDRAD2. At Best Buy, it's $50 new and $40 used. It's not super sensitive, but it's overall a good radio for cheap. The antenna is built-in, but is a quarter wavelength for most stations. I highly recommend it.
You're still getting something on FM, since analog signals reflect all interference they get while digital signals remain perfectly clean for as long as the 1s can be told from the 0s.
I have never heard AM sound so good. How the hell does it work? Must resample the audio and run some sort of upscaling on it. Very impressive. Shame AM is on the way out.
I am surprised that the HD system deals so effectively with the powerline re-radiation (the 120 Hz buzz). However, a friend demonstrated to me that stations on adjacent frequencies easily kill HD reception. This is because the HD portion of the signal is transmitted 5-15 kHz above and 5-15 kHz below the host station. DXing HD stations is possible but not probable.
Digital AM... might actually work better in the car than our DAB/DAB+ system works over here in the UK. Interference could be caused by something else plugged in or something being used by someone else in your grid section, but call the power company if all your radio's are affected, it can also affect your tv reception and broadband speeds.
in my place, am band is so noisy. only when grid power outage make it quite to sweep barely pickup nearest 120miles away am station and random other station at night. hd digital am is so great to eliminate noise and improve sound quality without sacrifices coverage with much less power than analog.(sorry for my bad english).
Drain tube, should have specified that. :/ Now that i think about it, it would sound better if it went though a vacuum tube, it would smooth out the sound.
Well I note all AM-FM stations in the USA comes through "a tube". I note this because I'm from Mexico and listening to AM stations from Texas and also listening radio via Internet I note 90% of radio stations uses some kind of audio processor that makes them listening like the audio is coming from "a tube". HD Radio just amplifies this due to clearer sound
I have a JVC KD- HDR-1 HD head unit. It has pretty decent reception. i took it out of my truck B/C i wanted a decent hd tuner for my listening room. Don't think they make them anymore. Sony at one time sold a really nice hd tuner. some years ago. but i think they discontinued it. Wish i had bought one.
+james42519 In Portugal AM is practically obsolete, there are a couple of low powered stations, I can barely receive them only at night, and even Spanish stations get here stronger.
ok. where i am there really isn't much am. everything is on fm. people still seem to want to pay for some satellite radio or use some app on phone though for some reason.
Dab has the potential for excellent audio quality or choice of many more stations with adverts$, I wonder which option they'll go for in the long term :-) With many stations broadcasting at 128kb/s your better off with FM in a lot of cases.
+Coolkeys2009 Right now its kinda in a beta test and like most beta's they are free. I heard from several station personalities locally that they want to make digital a pay subscription service and eliminate commercials with the option for the normal analog system free to listen to but with commercials.. IDK what they are going to do but the tech is there for them to do it.
I was an early adopter of HD-R, have a Sangean HDT-1 at home and had a Sanyo unit in the car. I was nonplussed by it. Not really needed for FM, and very artifact riddled on AM. Fringe reception on both was downright annoying (HD signal is transmitted using only 10% of the stations licensed analog power). Thunderstorms, overpasses and whatnot knocked out the AM band HD signal in the car with ease. I got rid of the car unit, and the home tuner just collects dust now. Lack of public enthusiasm for the technology (and the cost prohibitive yearly license for broadcasters) may make it an endangered species in a few years. A couple of local stations in my area have already shut down their HD exciters.
+hellhound1116 A pure sine inverter will not do anything because on DC systems like in a car or a solar power system the buzzing does not exist. It would be pointless to convert the 120v line to 12 / 24VDC and invert it back up and still have the buzzing, I have tried this and it will does work because its a grid noise. You need a pure DC source going into your inverter or run the radio off the pure DC itself and eliminate the inverter.
I have exactly same COBY HD radio receiver as it shown on your video. Your buzzing problem is cause by COBY cheap line power supply. You'll needed a 12 volt battery, this will solve your buzz-free problem on AM band.
No tipping broadcast industry on its ear and free stations from the corporations who screwed it up to begin with is a start. Technology has nothing to with what you are saying. Radio isn't going anywhere, but the current people running it need to go!!
I don't disagree about the corporate part of your comment, and I'm always hopeful, however IBOC FM was yet another technology pipe dream (like others of radio's past) that was designed to boost sagging radio ratings and marketing sales. It's safe to say at this time, it has not been the panacea, and does have some serious technical limitations........(range, constant buffering, delay and dropouts in the mobile environment) compared to the analog channel. Not saying it couldn't be changed to perform better, just that the current method does not appear to have a big future, and the competition is getting pretty tough for the radio biz. And electricity to operate a high power broadcast facility is not getting cheaper either. You might be shocked!
+paul larson I know the Ill's of the technology implemented. To take advantage of the digital broadcasting domain an analog shutdown would be needed but that highly limits signal propagation to the point it's useless as it is now with HD. . But here's what I mean about radio not going anywhere, other sources cannot compete with the one advantage radio has and that's portability!! But as far as the current levels of programming offered its not cutting it. Let's face it personality drove radio that does not exist in a voice tracked multiple ownership conglomerate world of sameness and all technology aside it wouldn't matter.its not gonna fix that. People aren't gonna listen to garbage on anything! .
Yes agree. They won't drop the analog. It's still where all the profit comes from. A switch to IBOC in it's current formula would be disastrous for the bottom line. Live programming can still be found on occasion, depending on your taste. But I suspect 90% of OTA today is either voice tracked or of satellite pre-recorded origin. Getting hard to make a profit. Then you have old 400' AM broadcast towers sitting on acres and acres of prime suburban real estate that is worth millions of dollars to developers. With AM being the less profitable side, I hear this is starting to tempt the owners into eating there own. /smh
+paul larson sure it is when your programming is lousy. It's all lifeless & soulless junk. I don't care what technology comes along you can't polish a terd . People made it go & programming made it go in the past. The whole thing of conformity and lack of competition now has ruined it.
In Europe we have dab which is a bit like it but its a different frequency so fm would be 97.0 and dab would be 233mhz dab would be fully digital but still people rather the old fm 87 to 108 easy tuneing
I'm on top of the mountain where FM radio is abundant. Some FM stations have definite sweet spots. When the extreme wind storm passed over the area in 2012 pass thru, even modern junk radios received stations probably 100 or more miles away. HD, on the other hand, has been far from abundant. Probably 3 of them are on the air in my area. AM radio becomes abundant at night, but my receiver has never latched onto HD AM.
Noise floor is better, and of course AM has a much better frequency response too, but honestly I think the digital compression sounds like refried ass. Some kind of obnoxious reverb too. Probably worth noting that this is the first time I have heard digital radio.
Even in HD still getting that radio Sound it's not full HD as in high definition sound. The buzzing in am must be grounding problem! I simply don't understand why fcc's doesn't get it rid of analog a.m. They are just dragging their balls on the ground when it comes to converting over to HD only!
there have been a couple AM stereo ch's,,fidelity these days on the sqwawky box is a lot better than 40 years go,,crowded as the fm dial is, & their 15 minutes of commercial shit every hour,,someone might take a stab at manufacturing a cheap am stereo converter for the home system,and the MX signal transmitter at the base.
I bet that was about 20 copyright strikes right there being the bastards they are about it. God forbid if you try to do a demonstration for anyone in an educational manner.
+Jacob S. Preciado These units are long out of warranty anyway. I know I bought mine during clearance on the dirt cheap and that was many years ago. This might be the best quality product to ever have the Coby brand printed on it.. it's, well, weird.
This video shows how corporate radio station using 'HD' jamming signals take up 2 extra channels of the radio dial on each side of the main channel sending a chainsaw like buzzing sound that obliterates small locally owned stations. You can observe this as you tune your radio dial across the channels any station using this fraudulent HD technology has this chain saw buzzing noise on a channel below and above the original licensed channel. HD stations take up 3 channels but you can only here the analog channel in the middle unless you can find and buy a new HD radio , and since less then 1% of the public owns HD radio's ( or even cares know about this ) you see this is really used as a way to jam out the smaller stations. Evil company's like Clear Channel ( now Iheart media ) and CBS ( now Entercom ) own and collect license fee's ( anti-trust, monopoly crimes ) from the hardware and lobby congress resulting in a 10 times power increase for the HD signal. These Corporate stations have 5 or 8 or more stations in every major city and when they add this insidious HD jamming signal each of clustered stations 'take-out' two more frequency from the public's airwaves , that is 10 or 16 more channels you only hear the buzz-saw signal on , channels that used to have good signals from smaller stations. The public has been duped by this corporate trick, even the name of the technology was a lie , its call I.B.O.C I-BOC standing for IN BAND ON CHANNEL , this is a lie , it is really in the FM band but on some one body else's channel. Another way of thinking about this is some fat-cat corporate business men in outdated suits come in and sit down at a bar , each of them start eating chicken wings , so many chicken wings there butts start overflowing to the bar stools on ether side of them forcing the other customers at the bar off the chairs. ua-cam.com/video/1OiH2lg_fes/v-deo.html
I bought one of those Coby tuners back in the day - still have it. The issue I have is with the included power supply when on analog AM. It is a major source of the hum I had that made analog AM unlistenable. I had a Kloss / Cambridge SoundWorks clock radio with HD AM and FM and it worked very well. Only reason I got rid of it was the back-lit LCD that completely lit the bedroom even on the lowest setting.
Anyone remember when Chrysler and GM both had AM stereo in cars? Sure it was analog, but the fidelity was improved.
Coby the name screams quality!
You have the same buzzing issue that we had in our neighborhood some years back. It was explained to me by someone at the power company. Two issues. First: bad grounds in the grid. Self-explanatory, they aren't maintained like they used to be. Secondly: Electric utilities used to employ filter chokes to help keep broadcast radio relatively free from coupling noise. Here in the northeast, utilities stopped using those about 20-25 years ago to cut costs. On strong MW signals, the power grid actually captures the radio signal, and sends it into the radio via the AC line. Since the radio is receiving the same signal via an antenna at the same time, the two signals mix, and what you get is a mess of 60hz buzz, but typically only on strong stations in the lower half of the dial. Your assumption that it's coming thru the grid is correct.
The AM HD sounds synthesized. It has a tinny, metallic sounding high end.
+Jim zz At least it's got some HF. AM is at best up to 4Khz
It's up to maybe 5Khz on the stations that have narrowed their bandwidth to accommodate the hash generator HD radio. AM can use up to 10Khz...and there are still some AM stations that are doing just that.
+Jim zz I doubt many AM receivers would make 5k, let alone 10k. Most are tuned to a peak for sensitivity and selectivity. Saying that an old British AM tuner (QUAD) did have a switch to decrease selectivity and flatten the bandwidth, did make strong signals sound quite good.
Michael Beeny Cheap radios such as battery-powered portable radios and table radios usually actually sound better on AM because it costs money to put in extra filtering to narrow down the bandwidth, so they leave those parts out and you get wideband AM radio. If you can hear the 10 kHz (or 9 kHz in Europe & Asia) adjacent carrier whistle at night, then you know your AM tuner has audio response up to at least that high.
@@vwestlife I noticed that my old cheap Sony receiver absolutely beats my dx-radios in terms of AM sound quiality, just because it has a wide filter. And with the help of an external ferrite antenna it becomes quite sensitive as well.
You have digital radio on AM as well? That's really cool! Here in Germany there's nothing left worth listening to on AM, most of the broadcasting sites have been shut down and demolished. We have digital radio too, it's called DAB+ (Digital Audio Broadcasting) but it uses the former VHF television band and higher frequencies, so the receiption is not always easy, especially in houses. Does HD radio in the USA use the same frequency bands as the analog stations? I listened closely with good headphones. On AM the improvement is - of course - outstanding. On FM it seems like not all station are using the same bit rate (kbp/s). On some stations you can make out the typical compressed sound or "digital artifacts" on HD while the FM signal sounds almost better (this is a problem with DAB+ here in Europe as well...some stations use really low bit rates so digital radio often sounds somehow "dull" compared to FM). On other stations you tuned in I did not notice the compression and the HD signal sounded even "brighter" than FM. This might result in the fact the normal analog FM audio signal range only goes from 30Hz to approx. 15kHz. Of course it could be due to different pre-equalization to make the HD signal sound much more better than it actually is. But in certain cases HD radio is an improvement for sure, especially if the analog signal is too weak so you would have to deal with background noise.
AudioMobil we have DRM on HF in Europe.
Yes, HD radio puts the digital carriers directly adjacent on either side of the analog signal. This has the effect of making one hybrid station take up the space of three analog stations with the additional digital carriers on both sides of the analog, so you can't have any directly adjacent stations in the same market. It's made the VHF FM band much more crowded as a result. In smaller markets, HD radio is rare to nonexistent because of the frequency coordination difficulties with adjacent stations. So you really only see HD radio in big cities like LA, Chicago, NYC, etc. The plan is to shut off the analog and only use the digital at some point, but that would mean all the old radios would cease to function just like analog TVs...
2:39 - Sounds like XM radio.
Can't believe this format is still alive
+k9feces
The only problem I have with HD radio (in the USA) is it's the only FCC approved digital broadcast system and all HD receivers sold include a royalty fee that goes to a shell corporation whose "investors" include major media companies. So you get to pay an extra fee to hear 40 minutes of commercials an hour with a slightly better sound quality.
HD radio has now been reverse engineered and you can download and compile a free program on your computer to listen to it with a SDR. The program is called nrsc5.
Totally unknown in Europe. They want us to use dab+ and throw our (vintage) fm radios away! The sound quality in am is amazing. Dab+ watch out!
HD Radio (IBOC) is better than DAB because it preserves the analog FM channel. However, FM radio stations in North America are spaced further apart, so IBOC technology works here.
Dab radio more sub channel , 8 sub channel , bitrate can 112 kbps , diferent frekwensi with radio FM
Don't hold your breath. HD Radio, despite being referred to as IBOC, isn't actually on-channel. Idk enough about AM in general to comment on it, but on FM, it needs a total of 400 KHz to work. The fact that we space our FM stations 200 KHz apart helps massively (seriously, any US radio with a digital tuner, you move the knob one notch or tap the button one time, and it'll jump from, say, 97.1 straight to 97.3). So too do some old allocation rules in which stations with geographically-adjacent or overlapping (official) service areas have to be at least 400 KHz apart.
Besides, HDR actually has developed a path to no-analog broadcasting in much the same vein. We already have four AM stations in the country which broadcast on the HD Radio All-Digital format - one authorized experimentally, the other three under new FCC rules from October 2020.
Norway has fully switched to DAB+ wuth the exception of some regional stations.
@@Toast0808 HD radio is not possible in many European countries because the frequency band is more crowded than in the USA. In the USA, the channel spacing is 200 kHz and in Europe 100 kHz. This would lead to a lot of interference with HD radio.
I can certainly hear that crispy, crunchy high end of over-compressed digital audio...
This is an excellent demonstration of HD radio. There wasn't any noticeable difference on FM with the exception of 93.9 when it went from analog to digital. The analog signal had some background white noise but when it went to HD mode, the noise was completely gone. Other than that, there was hardly no difference in the reception. AM is definitely an improvement of audio quality. I have a feeling that analog AM will soon disappear just like analog TV did because of the bandwidth and so many new wireless devices are being developed.
Funny, I was just asking you about this a few weeks ago. Great answer BTW. Man amplitude sounds GREAT here. Incredible. Good demonstration. I usually only listen to AM or broadcast for voice. Good stuff Shango. Steven
My car came with HD radio and it's great if you are in the range of a strong station. HD range is limited especially here in New England due the hills and mountains. I really get a kick out of some of the substations format wise. In Boston one station's substation is all Christmas music year round!
Cool, you have a Real Fm station too there. I bet yours plays better music then ours does! Our Real Fm is on 93.1. 😀
My guess is that the eq difference is caused by the lack of pre emphasis which allows for more highs. I notice the same thing on DAB here in euroland.
The hum might be rectifier diodes mixing 60Hz with the strong MW stations.
Some power supply circuits put small ceramic capacitors across the rectifier diodes to eliminate this type of problem.
would the buzzing be a feed from a internet through power line system? in our house I got the AM hum from a cheap Chinese charger plug.
I had a Coby MP305 as my first music player, and it came with a Kevin Macleod song on it i cannot seem to find anywhere.
I just ordered a Pioneer car radio with HD Radio, And now I am more interested in this. Especially with multiple channels in the same station.
nice demo video shane makes me want to get a hd radio but i dont hear fm stations advertising hd any more and i dont even know if any are left in the sarasota bradenton fl area
The AC adapter that came with my Coby HD Radio caused buzzing on AM. After I replaced it with a high quality power supply, the buzzing went away. Also, although mine was "new in box", the coin cell battery in the remote was dead. Most of the FM stations in LA seem to process their HD audio well, but many of the stations in NYC make their HD audio too bright and there is often an audible echo or flanging effect as the digital audio kicks in. And on 1260 KMZT you can really hear the shrill, metallic sound caused by the very low bitrate digital audio stream (36 kbps) that HD Radio uses on AM.
+VWestlife (backup account) Indeed my remote was dead out of the box too. Any tips on a power supply to let the AM work without hum?
Alan Maier I used the power supply that came with my Directed Electronics HD Radio. It is a Ktec model KA12D120150016U with 12-volt DC output at 1500 mA.
Our Czech National station is testing broadcasting purely on digital on AM using DRM system. It is not all that bad for bout 24kbps AAC with SBR and PS. But I don't any local way to receive it.
In my area two FM stations tried HD radio for about a year, and then abandoned it. I know one of the owners and he said the radios never sold and the yearly rates he paid to license the HD broadcasting equipment wasn't worth it.
I noticed that there were no digital AM stations tuned to that broadcast in stereo. Perhaps because of certain bandwidth limitations or other technical issues? The 60-cycle hum definitely disappeared when in analog mode on the AM band.
shame we don't have HD radio here we have DAB but most stations are mono though there around 100 on there.
but DAB can cover pretty good if more than one transmitter is used they have like 10 in Essex.
I suspect that much of the difference heard between analog FM vs HD has to do with the audio for these two programs going through separate processing chains. It is too much trouble to match them exactly.
It's a shame it sounds so similar. They had an opportunity to put out a clean signal in HD without compressing it to hell like regular radio. People who spend extra for HD radio are more likely to have the audio equipment and knowledge to take advantage of a high dynamic range. Then it would actually sound like real music.
The "Buzzing" exists here in Louisiana too, I think it is part of the new "smart grid" technology but that's my opinion.
It is HORRIBLE on the shortwave bands as well as AMBC..
When I go to battery power though it goes away unless I get close to an AC line cord.. It also goes away when I isolate my home off the grid and go 100% solar power running through pure sine inverters... SO yeah its on the grid whatever it is.
ElfNet Gaming another youtube blogger who did a review on these particular sets reckons it's to do with the power supply units which comes with them
The unfortunate truth is that HD radio isn't HD quality. Not even close. In an effort to cram as many multicast stations as possible on one signal, the quality has gone to junk due to bandwidth squandering, just like SiriusXM. In my market, the bitrates vary from 23-56 kbps (HE-AAC encoding). Even at 56 kbps (the max in my market), I can hear tons of compression artifacts in the high end with HD radio. It's so bad I've actually shut off HD radio in my car and only listen to the analog FM signals because they sound so much better. The station engineers treat HD radio like a bastard child-the EQs and volume levels are often way different between the analog and digital, so you get blasted with treble, get bass clipping on the mumble rap stations, or have to crank up or down the volume when it switches from analog to digital. The local classical music station also has their L and R channels reversed in their HD signal vs. analog. This is basic A/V stuff people. I've never heard a full 96 kbps HD radio station to see if it's acceptable or not. But that would mean only one HD station, so station managers aren't going to do that when they could have three or four multicast stations making money because who cares if they sound terrible? The other topic that bugs me is why modern AM radios only have an audio bandwidth of less than 5 kHz when the AM signals are broadcast with 10 kHz (and before that it was 15 kHz). They chose 5 kHz to eliminate the possibility of any adjacent station interference, but if there's nothing next to your favorite AM station, there's no reason why you couldn't get the full 10 kHz. As I understand, they made some AM radios with a narrow/wide switch to solve this problem, but I've personally never seen one. This oversight is going to be the death of AM radio because modern receivers with fixed 4-5 kHz bandwidth just sound too horrible for most people to tolerate before hitting the FM button.
We adopted the DAB+ broadcasting standard here in Australia and it's only being broadcast in our capital cities at present, most of the city stations are simulcasting on DAB+ and are also using AAC encoding, and although they all are using different bitrates, there's not much difference between analog FM and digital, there is, of course, a vast improvement in quality compared to analog AM and each station has it's own digital only stations, the vacant Digital TV Channels in VHF Band III are being used to broadcast DAB+ here, which, with any radio standard, has it's pros and cons.
Tried a ground loop isolator yet? I have had to use in places with grounding issues.
I have several HD radios. Both FM only and some FM/AM. I've found that they use more higher end audio EQ and stereo separation. However a NON HD Radio station, WGSQ FM sounds great on FM without the digital only signal, simply better preprocessing and use of the exciter. I feel Digital does offer more in the scheme of more stations or channels in the same carrier/ssb. That's Bout it. I would prefer a HQ preprocessing analog signal on FM or AM and RDS as apposed HD Radio.
Hey Shango, if you still have this radio, take it with you the next time you go out into KYET Cactus Country territory. This model can decode C-QUAM AM-stereo. It's one of the few HD radios that can. Don't get your expectations too high with it though, they are narrow and I do believe the stereo channels will be flipped. They also like a decent signal, so it probably won't decode off weak DX.
Looks like a DAB /DAB+ device. I got a Ruark, nice walnut cabinet, not the best bit rate but lots of station.
Seems to be a bit more treble in the audio with HD FM. A bit better frequency response with HD FM vs. regular FM.
Wow! Cool! Sounds great here :)
Can this unit be used in a car?If so how do you hook up the audio, antenna and the 12 v
do they still sell these?If so ,where?How much $$$??
Love that jazz song on 94.7
My latest car has HD Radio built-in and the difference between normal FM and HD FM is significant. Very noticeable.
Did you buy that on Amazon? If so, could I get a link? I've been wanting to get a decent FM receiver as my Sansa Clip+ doesn't have the best receiver.
Vynncent Murphy I know this is a little late, but a much better radio than this Coby one is the Insignia NS-HDRAD2. At Best Buy, it's $50 new and $40 used. It's not super sensitive, but it's overall a good radio for cheap. The antenna is built-in, but is a quarter wavelength for most stations. I highly recommend it.
I don't get it ... is there an additional (digital) carrier on the same frequency?
+Das OSi Yes.
ElfNet Gaming interesting, thanks
You're still getting something on FM, since analog signals reflect all interference they get while digital signals remain perfectly clean for as long as the 1s can be told from the 0s.
Perhaps the impressive improvement is in Am Band is really impressive
I have never heard AM sound so good. How the hell does it work? Must resample the audio and run some sort of upscaling on it. Very impressive. Shame AM is on the way out.
I am surprised that the HD system deals so effectively with the powerline re-radiation (the 120 Hz buzz). However, a friend demonstrated to me that stations on adjacent frequencies easily kill HD reception. This is because the HD portion of the signal is transmitted 5-15 kHz above and 5-15 kHz below the host station. DXing HD stations is possible but not probable.
Digital AM... might actually work better in the car than our DAB/DAB+ system works over here in the UK.
Interference could be caused by something else plugged in or something being used by someone else in your grid section, but call the power company if all your radio's are affected, it can also affect your tv reception and broadband speeds.
High pitch digital compression noise. Way better.
in my place, am band is so noisy. only when grid power outage make it quite to sweep barely pickup nearest 120miles away am station and random other station at night. hd digital am is so great to eliminate noise and improve sound quality without sacrifices coverage with much less power than analog.(sorry for my bad english).
Coby - Chinese Original Broken Yesterday
Anyone mind posting a list of the songs that were playing? Some of them sound pretty good.
+Scowler I know one was Abba - Dancing Queen.
TheRetro1986
Okay.
Anyone know what song plays at the end?
The digital sounds at some points like its coming through a tube, that pretty much the only way I can describe it.
+PINKBOY1006 You mean a tube like a drainpipe, not a vacuum tube, right?
Drain tube, should have specified that. :/ Now that i think about it, it would sound better if it went though a vacuum tube, it would smooth out the sound.
Well I note all AM-FM stations in the USA comes through "a tube". I note this because I'm from Mexico and listening to AM stations from Texas and also listening radio via Internet I note 90% of radio stations uses some kind of audio processor that makes them listening like the audio is coming from "a tube". HD Radio just amplifies this due to clearer sound
IBOC Digital radio broadcasting system should become popular outside of United States, for Japan, Korea and Taiwan regions.
That Cobb you have needs a better power transformer that's isolated and shielded.
Coby
I have a JVC KD- HDR-1 HD head unit. It has pretty decent reception. i took it out of my truck B/C i wanted a decent hd tuner for my listening room. Don't think they make them anymore. Sony at one time sold a really nice hd tuner. some years ago. but i think they discontinued it. Wish i had bought one.
Why is am still around? I know no one that listens to it really and it usually sounds worse and has Interference compared to fm.
+james42519 Its actually great for talk radio or information stations
+james42519 coverage range
+james42519 In Portugal AM is practically obsolete, there are a couple of low powered stations, I can barely receive them only at night, and even Spanish stations get here stronger.
ok. where i am there really isn't much am. everything is on fm. people still seem to want to pay for some satellite radio or use some app on phone though for some reason.
james42519 Try listening to AM at night with a decent antenna. You will be surprised at how far you can receive a signal
It sounds as though there are more dynamics on the digital band as well (the analog FM sounds more compressed than the digital band)
Best thing is it's free. Tired of paying the Sirius XM fees, even with the discount pricing.
Dab has the potential for excellent audio quality or choice of many more stations with adverts$, I wonder which option they'll go for in the long term :-) With many stations broadcasting at 128kb/s your better off with FM in a lot of cases.
+Coolkeys2009 Right now its kinda in a beta test and like most beta's they are free. I heard from several station personalities locally that they want to make digital a pay subscription service and eliminate commercials with the option for the normal analog system free to listen to but with commercials.. IDK what they are going to do but the tech is there for them to do it.
+ElfNet Gaming Never mind that system is different from Dab used over here, should have some newer better codecs.
I was an early adopter of HD-R, have a Sangean HDT-1 at home and had a Sanyo unit in the car. I was nonplussed by it. Not really needed for FM, and very artifact riddled on AM. Fringe reception on both was downright annoying (HD signal is transmitted using only 10% of the stations licensed analog power). Thunderstorms, overpasses and whatnot knocked out the AM band HD signal in the car with ease. I got rid of the car unit, and the home tuner just collects dust now. Lack of public enthusiasm for the technology (and the cost prohibitive yearly license for broadcasters) may make it an endangered species in a few years. A couple of local stations in my area have already shut down their HD exciters.
good vid
Try a pure sine wave inverter her to get rid of that buzzing sound
+hellhound1116 A pure sine inverter will not do anything because on DC systems like in a car or a solar power system the buzzing does not exist.
It would be pointless to convert the 120v line to 12 / 24VDC and invert it back up and still have the buzzing, I have tried this and it will does work because its a grid noise.
You need a pure DC source going into your inverter or run the radio off the pure DC itself and eliminate the inverter.
I have exactly same COBY HD radio receiver as it shown on your video. Your buzzing problem is cause by COBY cheap line power supply. You'll needed a 12 volt battery, this will solve your buzz-free problem on AM band.
IBOC was OTA FM's last great hope for relevance in a changing world. RIP.
No tipping broadcast industry on its ear and free stations from the corporations who screwed it up to begin with is a start. Technology has nothing to with what you are saying. Radio isn't going anywhere, but the current people running it need to go!!
I don't disagree about the corporate part of your comment, and I'm always hopeful, however IBOC FM was yet another technology pipe dream (like others of radio's past) that was designed to boost sagging radio ratings and marketing sales. It's safe to say at this time, it has not been the panacea, and does have some serious technical limitations........(range, constant buffering, delay and dropouts in the mobile environment) compared to the analog channel. Not saying it couldn't be changed to perform better, just that the current method does not appear to have a big future, and the competition is getting pretty tough for the radio biz. And electricity to operate a high power broadcast facility is not getting cheaper either. You might be shocked!
+paul larson I know the Ill's of the technology implemented. To take advantage of the digital broadcasting domain an analog shutdown would be needed but that highly limits signal propagation to the point it's useless as it is now with HD. . But here's what I mean about radio not going anywhere, other sources cannot compete with the one advantage radio has and that's portability!! But as far as the current levels of programming offered its not cutting it. Let's face it personality drove radio that does not exist in a voice tracked multiple ownership conglomerate world of sameness and all technology aside it wouldn't matter.its not gonna fix that. People aren't gonna listen to garbage on anything! .
Yes agree. They won't drop the analog. It's still where all the profit comes from. A switch to IBOC in it's current formula would be disastrous for the bottom line. Live programming can still be found on occasion, depending on your taste. But I suspect 90% of OTA today is either voice tracked or of satellite pre-recorded origin. Getting hard to make a profit. Then you have old 400' AM broadcast towers sitting on acres and acres of prime suburban real estate that is worth millions of dollars to developers. With AM being the less profitable side, I hear this is starting to tempt the owners into eating there own. /smh
+paul larson sure it is when your programming is lousy. It's all lifeless & soulless junk. I don't care what technology comes along you can't polish a terd . People made it go & programming made it go in the past. The whole thing of conformity and lack of competition now has ruined it.
HD Radio adds in the high frequency which sounds like a 64 KBPS MP3! They should broadcast SPDIF signal via VHF, but the FCC and RIAA don't want that!
In Europe we have dab which is a bit like it but its a different frequency so fm would be 97.0 and dab would be 233mhz dab would be fully digital but still people rather the old fm 87 to 108 easy tuneing
You need a surpressor mate
Recently got an in dash HD unit for the car. The range isn't that great. Cuts out like digital TV.
I'm on top of the mountain where FM radio is abundant. Some FM stations have definite sweet spots. When the extreme wind storm passed over the area in 2012 pass thru, even modern junk radios received stations probably 100 or more miles away. HD, on the other hand, has been far from abundant. Probably 3 of them are on the air in my area. AM radio becomes abundant at night, but my receiver has never latched onto HD AM.
⭐⭐
Noise floor is better, and of course AM has a much better frequency response too, but honestly I think the digital compression sounds like refried ass. Some kind of obnoxious reverb too.
Probably worth noting that this is the first time I have heard digital radio.
Dancing queen 101.1-1
Analog power saving energy high watts.
Prefer analog when signal is good.
Even in HD still getting that radio Sound it's not full HD as in high definition sound. The buzzing in am must be grounding problem! I simply don't understand why fcc's doesn't get it rid of analog a.m. They are just dragging their balls on the ground when it comes to converting over to HD only!
there have been a couple AM stereo ch's,,fidelity these days on the sqwawky box is a lot better than 40 years go,,crowded as the fm dial is, & their 15 minutes of commercial shit every hour,,someone might take a stab at manufacturing a cheap am stereo converter for the home system,and the MX signal transmitter at the base.
sounds same as cleveland broadcast radio
most stations killed the HD signal
I bet that was about 20 copyright strikes right there being the bastards they are about it. God forbid if you try to do a demonstration for anyone in an educational manner.
Coby high volume.
no cambio mi Sony STR 212 ni tampoco mi Imperial Salzburg por esas mierdas digitales
new radio technology and they couldn't make it quad channel audio.
Some time ago, there were manufacturers that wanted to use HD FM to bring Dolby 5.1 surround sound to cars.
europe dab+ radio
He radio has more stations
The extra stations are not worth it. Bad content
Coby is out of bussiness, if this device fail, don't send it to warranty.
+Jacob S. Preciado These units are long out of warranty anyway. I know I bought mine during clearance on the dirt cheap and that was many years ago. This might be the best quality product to ever have the Coby brand printed on it.. it's, well, weird.
Can definitely hear when the switch from analog to digital happens. I prefer the fuller sound of analog more than the HD.
Haha Houston
AM/FM Radio Analog Shutdown.
Get yourself 12 volt battery to kill ac 60Hz buzzing noise because COBY is very cheap Chinese brand.
This video shows how corporate radio station using 'HD' jamming signals take up 2 extra channels of the radio dial on each side of the main channel sending a chainsaw like buzzing sound that obliterates small locally owned stations. You can observe this as you tune your radio dial across the channels any station using this fraudulent HD technology has this chain saw buzzing noise on a channel below and above the original licensed channel. HD stations take up 3 channels but you can only here
the analog channel in the middle unless you can find and buy a new HD radio , and since less then 1% of the public owns HD radio's ( or even cares know about this ) you see this is really used as a way to jam out the smaller stations. Evil company's like Clear Channel ( now Iheart media ) and CBS ( now Entercom ) own and collect license fee's ( anti-trust, monopoly crimes ) from the hardware and lobby congress resulting in a 10 times power increase for the HD signal. These Corporate stations have 5 or 8 or more stations in every major city and when they add this insidious HD jamming signal each of clustered stations 'take-out' two more frequency from the public's airwaves , that is 10 or 16 more channels you only hear the buzz-saw signal on , channels that used to have good signals from smaller stations. The public has been duped by this corporate trick, even the name of the technology was a lie , its call I.B.O.C I-BOC standing for IN BAND ON CHANNEL , this is a lie , it is really in the FM band but on some one body else's channel.
Another way of thinking about this is some fat-cat corporate business men in outdated suits come in and sit down at a bar , each of them start eating chicken wings , so many chicken wings there butts start overflowing to the bar stools on ether side of them forcing the other customers at the bar off the chairs.
ua-cam.com/video/1OiH2lg_fes/v-deo.html