: HD Radio in Canada


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CamDAB
2008-04-03, 10:21 PM
Westsider, thanks!

Thus, I take it that there is less compression of the digital audio path?

The remark about mp3 can be whole topic onto itself. :-) If I remember correctly, they're using a form of AAC-HE, or one of it's variants. The next thing is to test the HD2 feeds, if the station(s) have made use of that part of the system.

I seem to remember you mentioning that the digital takes a number of seconds to lock.
Now *that* will add a whole new demension to FM DX'ing.... Getting a digital signal via tropo, inversion or sporadic E. :-)

Cameron

westsider
2008-04-04, 09:58 PM
All the stations heard are running a single " -1 " HD program and hopefully many will continue. The recovered digital audio sounds like it has a higher dynamic range. I would guess that the noise floor is near or slightly lower than that of local analog stations not running SCA carriers.

I suspect the HD will survive DX paths but might get trashed if there is co-channel interference. Similarly, the more distant HD stations might loose lock due to background DX. One station experiencing frequent drop-outs to analog has a co-channel station much closer to me in a different direction. I am probably going to have to tweak the antenna direction to minimize it.

Tom.F.1
2008-04-07, 01:58 AM
I spent the weekend installng an HD Radio in the Car.
It's an Alpine TUA-T500HD with an Alpine CDA-9887 Head unit.
AM & FM reception is better than the head unit alone, maybe because the tuner is in the trunk, away from all the cars electronics in the dash and closer to the antenna. The antenna is in the rear window and amplified, the car came that way.
Here in Ajax, I get 3 Buffalo stations in digital, 98.5, 102.5 & 106.5. All have HD2, so six progams.
Sound quality is definately better than the analog, just because of the extended frequency response. (Hey, there' cymbals on those drums!)
Driving around town here, it drops out of digital quite often, buildings & bridges. But it is better near the lake. When it drops digital it goes to the regular FM, very noisey and muted, but the timing is better than i expected. When I was on the second channel HD2 and it dropped out it goes to silence, I thought it would still go to the FM.
The radio has a choice of 6 or 56 character SCL display. The 56 is a bit ridiculus, its scrolls or flashes because it can't fit it all on the display. I don't need the stations and slogan flashing at me again and again. I shut that off pretty quick, I can't stand anything flashing at me from the dash.

CamDAB
2008-04-08, 02:04 PM
Tom.F.1 thanks. The more reports on this stuff the better. And, even though I'm not a driver, I concur that the less stuff flashing on the dash, the better. :-)

The 64 cent question I'm awaiting the answer to, is, what does HD do with fairly strong signals in a severe multipath situation. This is common in high-rise buildings, (such as I'm in). This would take probably a listener in Buffalo or wherever to answer.

However, it's an improvement when at least they have some consideration for the digital signal. Most of the DAB engineering has been atrocious on the Canadian side, with a few exceptions.

Jazz FM, CBC and Q107 are fine. Some are OK... And the rest... Well....

Cameron

Tom.F.1
2008-04-08, 02:21 PM
Cam, part of the reason i got the new car radio is because i usually do a lot of travelling in the US. But unfortunately, no plans to go south till my vacation end of July. I thought i'd get more Buffalo stations than i do. :confused:

rob50312
2008-04-08, 06:23 PM
Cam there was a test by cbc using HD radio conducted in downtown Toronto a while ago and they reported no multipath problems at all.You can read this report on cbc technology review.Tom HD radio power levels are 1/100 of analog so fringe areas not covered by HD radio.Also 106.5 is also being used by aboriginal radio in Toronto.At my house i receive the Toronto station on analog 106.5 but sometimes the digital 106.5 WYRK comes in.Good job I ndustry Canada putting a transmitter 60 miles apart on the same frequency.

FLACer
2008-04-10, 12:48 PM
Jazz FM, CBC and Q107 are fine. Some are OK... And the rest... Well....

I know I brought this up before, but is there any chance you could post some clips of Jazz FM, CBC R2 and/or Q107 somewhere on the web? :D

CamDAB
2008-04-10, 04:19 PM
I know I brought this up before, but is there any chance you could post some clips of Jazz FM, CBC R2 and/or Q107 somewhere on the web? :D
Creating the clips isn't the issue, as I can output them in .wav, .ogg, .mp3, and .m4a (the default for iPod) an AAC file container. The problem is where to post them and not worry about bandwidth limits... :-)

Cameron

Random Dude
2008-04-11, 10:39 AM
I can't believe the government would choose a different standard from the US. Now if you want both Canadian and American stations, you have to have 2 different recievers?

westsider
2008-04-11, 10:00 PM
Great report, Tom. It sounds like the multi-program HD stations are on the rise - oh well quantity vs. quality.
The HD-1 normally carries the same program as the analog FM so dropping in and out maintains listening continuity - like same song or news but just degraded quality during the fade. They plan on different program streams on HD-2, HD-3, etc.- like sports or whatever - so the radio makers suspend the switching (so you dont go back and forth between a baseball game and a symphony).

Random Dude
2008-04-12, 07:35 AM
I have another question here...

Radio Data System (RDS) is analogue-only, right? Does it have anything to do with digital radio?

classicsat
2008-04-12, 10:11 AM
Normal RDS is FSK data on an analog subcarrier (IIRC, it uses the Bell-202 standard, same as caller ID and amateur packet radio).

HD-Radio would have its own version, with the RDS data directly embedded into the bitstream.

FLACer
2008-04-13, 12:57 PM
Normal RDS is FSK data on an analog subcarrier (IIRC, it uses the Bell-202 standard, same as caller ID and amateur packet radio).

HD-Radio would have its own version, with the RDS data directly embedded into the bitstream.

I think RDS is one of the coolest (yet highly underutilized) features of analog FM radio. I happened to discover that there is an equivalent for this for AM radio called AMSS - Amplitude Modulation Signalling System:

http://en.wikipedia.org/wiki/Amplitude_modulation_signalling_system

Since it's an extension of Digital Radio Mondial, I assume HD-Radio could embed this data into their bitstream as well?

ashteven
2008-04-21, 03:33 PM
Hi there

I'm trying to improve the signal of 103.3 WEDG Buffalo in my car. I live in Toronto. I've tried three different car antenna's and nothing seems to work. It's a new Sony CDX-GT420U head unit.

WEDG broadcasts in HD so I'm wondering if buying & installing an HD tuner (Sony XT-100 HD) get rid of the static? Any other suggestions?

Thanks in advance!

rob50312
2008-04-21, 04:37 PM
Receiving 103.3 from Buffalo in HD will not likely be possible because of adjacent channel interference and the 1/100 power level of HD radio.An HD radio tuner may improve your regular reception of the station because the hd tuners are usually more selective in tuning.I have received 103.3 in HD only once during a good reception day but my analog reception is very good using an antenna in my attic.Are you receiving interference splatter from 103.5 or is it impulse noise from the car when it is running or just normal multipath fading out with a distant station.HD radio has a shorter range than analog FM.

Random Dude
2008-04-22, 08:59 AM
Are any of the Toronto stations broadcasting in HD?

ashteven
2008-04-22, 12:33 PM
Thanks for the info, Rob50312. The problem is most definitely interference from 103.5, not from the car itself.

Do you think the problem is the Sony stereo, in that the FM sensitivity is rated 9dbf? In my other car, which uses a Pioneer deck with an FM sensitivity of 8dbf, there's barely any interference and the station comes in much more clear.

rob50312
2008-04-22, 05:32 PM
No Toronto stations in HD.The Pioneer tuners usually have better selectivity than most other brands.This is very important in dealing with stations adjacent to each other 103.5,103.3.Most manufactures list only alternate channel selectivitity.Look for higher numbers 70db or more.

westsider
2008-04-25, 07:22 PM
The RDS, if a station has installed it (and many have), continues to remain operational on analog when the station equips ibiquity (IBOC) HD. HD radios seem to still present the analog RDS data on the display. I see the same messages (e.g. call sign, name of artist, name of track and/or advertisements) whether in HD mode or analog mode.

I was expecting a "digital" form of RDS but have not seen it. When the radio is locked in HD mode (which seems to require around a 55 to 60 dB carrier to noise ratio) and the signal is having a bad hair day (as in significant multipath) I have seen the RDS display incomplete or discontinuous messages.

With a low data rate like RDS they ought to throw in some error correction. However, the messages are usually repeated many times over and if someone really cares they can watch it for a while to figure it out (human error correction).

The call sign seems to be more robust. Perhaps the radio caches it.

westsider
2008-06-27, 03:06 PM
There are various L-band antennas (short LP yagis) for sale, posted on several EU websites. If you want to receive what is left of DAB in Vancouver, then an external antenna is likely necessary - unless you have a clear view of Mount Seymour. Before spending much effort, be aware that DAB is at high risk for going off the air in Canada, as people are watching the progress of the US IBOC (iBiquity) system.