Why HD Radio Sucks on AM - A demonstration

This demonstration was done with a Grundig s350 model radio during the evening hours. It showcases Radio Disney 910 KWDZ how well it sounds without IBOC and the problems created by KSL 1160's IBOC signal. This is an analog radio that differs from most off the shelf radios in that it can narrow the bandwidth of the audio down to 6khz in order to block out adjacent channel interference. It also has a wide mode which is common to almost all analog radios to date.

KSL AM has their IBOC off more than on now days (as of Late August 2009). Yay! I can hear KFAQ again!

Category:

Science & Technology

Tags:

• HD
• Radio
• sucks
• KWDZ
• KSL
• AM
• IBOC
• High
• Definition
• crap
• radio
• disney
• dx
• grundig
• s350
• KUTR
• KFAQ
• 1160
• 910
• 820

[s51curtis]

I think you've missed the point. I'd like to see you do this demo again, only compare the sound of KSL on your analog Grundig against the sound of KSL digital on an HD Radio. I was blown away the first time I heard an HD signal on an HD Radio on the AM band. Granted the idea the two technologies can happily co-exist is flawed. I just doubt that AM technology with it's 10kHz bandwidth and poor S/N ratio is going to last much longer in this digital world.

[Ubstudios]

@s51curtis I hate to agree about AM technology not lasting much longer but its becoming an unfortunate fact. As far as KSL's HD sound compared to analog, you're right, it does sound better, albeit with digital artifacts. As finicky as the signal is for an HD AM station (you practically have to live on top of the tower for the station to sound the best), I really question its worth. In this situation, KSL is also on FM, so it doesn't make much sense to broadcast their AM AND FM in HD.

[Teflon65]

I re-watched your video, and re-read your comments. You said that IBUZ doesn't affect FM, so it's still a little mystery to me as to why a local FM station is coming in better now. Regardless, I find your video interesting, and I don't think CFC lightbulbs, or other RIF could make the noise the HD signals seem to be making. One more thing, I think analog AM sounds a lot better on an old tube radio. Any thoughts on that?

[Ubstudios]

@Teflon65 Yeah, sometimes the older the radio, the better AM sounds. The Grundig in the video is probably the best sounding radio I have. The others do not have the wide switch or are too wide that they allow adjacent stations to bleed badly. The radio in the video can switch between narrow mode (10khz) or wide 10+ khz so you can hear the whole sound. I prefer narrow though, because the S350 is a hot AM receiver.

[Aviator14]

There is also a local 50,000 watt station in my area with HD and it wipes out anything 30khz above and below the frequency, also the hiss makes it annoying, if you listen to it in HD it has that metallic sound that a low quality mp3 would have. Also sometimes the signal will switch back and forth between HD and analog if the weather is bad. I think it is a total disaster

[andycflbulb]

@RayAir1 when starting up, CFL light bulbs will cause a Pop! to be heard on low-left FM (88 and 91)

[Aviator14]

It sounds like they are splattering. An AM station is not supposed to be heard over 40khz wide.

[Ubstudios]

@Teflon65 I'm not sure where you live but you may or may not have an AM station that carries HD at night (or during the day for that matter) near you. The ones I have around me now are KOA 850 and KSL 1160. KSL used to be worse when I lived in SLC, but not as bad now that I'm 150 miles distant.

[Teflon65]

@Ubstudios I switched to the AM dial on my analog radio, for a minute, and only place I noticed that annoying buzz was coming up on our local Clear Channel station. Everything else sounded fine, including the Clear Channel station itself.

[Teflon65]

@Ubstudios That's interesting. I need to do more research. Now, I'm wondering if I can hear this one station better because another station shut off its IBUZ. I had kind of given up on listening to this station, but it's coming in as good now as it did years ago, and that's just on an analog radio. I probably need to re-watch your video again too. Thanks for your help; I'm learning stuff.