We've had some colossal missteps when it comes to radio, and from my perspective some has been marketing, some technical, some both.

AM Stereo: Marketing wasn't bad, but the system suffered from too many systems that were not compatible, and nighttime reception problems. The market was totally in confusion by the time Motorola became dominant.

DAB: Marketing was poor and didn't have focus, receivers weren't marketed very well and there were some notable incompatibilities. Receivers were expensive and didn't work well, and for many, confusing to operate. Coverage and implementation was dreadful at times. CBC missed a golden opportunity creating a national SFN (single frequency network) which is a natural for DAB.

Digital Radio Mondiale (DRM): Another digital radio format for AM, SW and FM (DRM+) bands. Shortwave usage is starting to get spot treatment. Tests on the FM band has been done in some countries with interesting results. This is not a proprietary closed system, but along the lines of "open source" type of licensing to a degree, unlike HD Radio. No North America marketing that I'm aware of. CBC has been using it on 9.800MHz (9.800KHz) daytime.

HD Radio: Gaining traction in larger US markets. Sound is great when done correctly. Being on the edge of digital coverage does create problems in the analogue to digital switchover and back to analogue cycling. Approved for use in Mexico (recent). Mexican use also includes use of fully digital modes of HD Radio...

Unless there's been a recent change, Canada currently allows AM, FM, DAB, DRM, IBOC (HD Radio in hybrid mode) methods of transmission, the newer digital systems are on a case by case basis.

Somehow, we didn't learn anything from the AM Stereo debacle...

Cameron

Here is my set up.., location Montreal, DB8 antenna plus a CM3414.

I was using the CM3414 to split the signal as well to feed my TV and my HD Radio. The reception of WVPS-FM 107.9 HD signal was always very good with this set up.

September 1st rolls around, and all of a sudden I find that my FM reception seems to have gotten worse. No HD Radio coming in, and even the analog part of WVPS-FM seems too static. Of course not all stations effected. And weird stuff like cross over signals on 87.5 fm. We use to have a analog channel 6 in the city, and it shutdown with the DTV switchover. I figured everything should be quit between 87.5-87.9. Not really.

I played around with the set-up. I found out that if I remove the CM3414 from the mix, and go direct to the HD Radio, reception is great. So, I'm thinking that there is something wrong with my CM3414. I compare the TV signals with and without the CM3414, and the TV's signals seem better with the CM3414. Without it, I would even loose a few local DTV stations. Can't have that.

So far, I have left the DB8 antenna and the CM3414 to feed my TV. I have placed the wire FM antenna that came with my HD radio indoors. FM reception has improved. No weird signals coming over 87.5 fm, but the HD Radio signal cuts in and out. But what can I do for now. Other than wait for WVPS-FM to increase the power on their HD signal.

My question is, can a shutdown of certain analog TV stations effect certain FM frequencies and what a distribution amp can pick up or not. We use to have analog channels 2,6,10,12,17,35,46,62. We now have Digital 10,12,15,19,21,26,35,49

I should just get a FM outdoor antenna, but, I can't ask the building I live in to allow me to place another antenna on the roof. There is a limit to how far one can push things.

Shutting down the analog transmission of TV should not harm reception of FM radio, however, the possibility exists that the new DTV transmission, if it is nearby might negatively impact your FM reception. It's a bit early to tell, but generally since DTV uses less power, the overall impact should be less than the older megawatt analog stations.

With the Sony FM-HD tuner, terrible PIA having borderline reception (which is the case for everybody in Toronto at one time or another).

There is a tech-fix involving cutting a tiny circuit board trace and adding a switch (or just cutting which cancels all HD reception).

Weather and tropo has been weird in Toronto past while and maybe for you too.

And many stations are still experimenting with their set-ups.

Seems to me that a strong antenna signal is the foundation of all reception and there are no good downstream compensations. Sadly, sometimes that can make HD more borderline, if your were previously sub-borderline and getting only excellent Sony FM-stereo.

Sure wish Sony would come out with an upgraded unit (for a downscale price).

Ben

Question: my still-only-occasional HD reception from PBS Buffalo sounds like it has strong bass (almost like crap-pop stations boost their bass sometimes). I suppose there is more bass extension with HD's freq response, but is there some boost in HD relative perhaps to FM-stereo bass rolloff? Does FM-stereo roll-off at a high freq like 50 Hz?

Ben

I wouldn't consider 50 Hz to be high frequency. ;)

However, FM radio uses pre-emphasis of high frequencies, at the transmitter, and matching de-emphasis, at the receiver, in order to reduce high frequency noise. If the filter in the receiver rolls off quicker than required for de-emphais, you will lose some of the high end. There is no need to do that with digital radio (though there are other issues) which should produce "CD quality".

Ben,

The low end cut off can be lower than that, sometimes 30, even 20Hz but it can be higher too for the analogue stream. Turntable rumble and subsonics, if not filtered properly, would wreak havoc causing all kinds of intermodulation effects and or huge woofer excursions, especially when blending one turntable cut to the next.

With CD and music file sources, that subsonic content isn't present, or with current processing is filtered more, and thus not an issue so much with analogue.

If processed lightly, HD Radio certainly could add a punch that analogue could not reproduce, or reproduce cleanly. It all depends on how the source material is handled to each transmission medium.

On a side note, (and could be a thread of it's own), Has anyone noticed the copious amounts of compression on CBC Radio 2 from Toronto over the last couple of years? Radio One sounds OK, and I'd expect more compression / processing for mostly talk content. But Radio 2, well, it's almost unlistenable at times... When they had their DAB feed running, I'd much prefer that as it was generally untouched or lightly processed. But that was until they pulled the plug on that..... :-(

Cameron

Thanks for replies about HD bass versus analog bass.

I take for granted it is easy for HD to have wide and flat response. But JamesK, are you saying HD uses high frequency EQ to subdue noise the analog has always done so?

Loudspeakers (except sealed boxes) have no means of subduing wild motions of their cones on low notes. But fancy systems sometimes have sub-sonic protections, like you'd want to have with analog FM. Likewise, I suppose analog FM needs protection from over-modulation on wild bass.

But can HD transmit wild bass without distortion (up to a digital limit, of course) and so only limits it in the interest of preventing say, turntable rumble or other source signal from getting through?

Ben

No, I wasn't referring to equalizing. With digital, you need a filter to cut off frequencies approaching 1/2 the sampling rate, to avoid aliasing. It's not so much a problem now if oversampling is used, but it could cause some roll off of the high end. Digital in general avoids many of the problems of analog systems. Once past the A/D stage, it's just data that can be transported, stored, error corrected etc., without any of the degradation that analog systems introduced. HD can transmit whatever you want that's within the range of the A/D converter, which is generally, for CDs, DC to almost 22 KHz. CDs also have a dynamic range of about 96 dB, which is determined almost entirely by the number of bits in the system. Each bit contributes 6 dB to the dynamic range, so 16 x 6 = 96 dB. I don't know what the comparable numbers are for HD radio.

FYI...

WVPS-FM 107.9 Burlington, VT seems to have increased their power output for their HD Radio signal.

So, those who have had problems locking onto their HD Radio signal in the past should give it a try now and see if it works better.

My New Company car does not have an HD Radio tuner.This needs to standard equipment for HD radio to succeed.The car does have Sirius Sat. tuner.No wonder no HD radio stations in Canada.The sat. radio does not sound as good as HD radio.The sat radio may not seem as good as few good analog FM stations.You cant easily change radios in cars anymore.

HD Radios seem to be now available in either standard or optional packages for some cars in the US.

If I was in the market for a new car, I would certainly ask the Canadian car dealer to arrange one of those packages to be installed.

Here is a video about what is going on with some of the HD Radio units.

http://www.youtube.com/user/RadioInkads?feature=mhee#p/u/2/0y5hJyc1bBQ

Here is a short youtube video that I found that showcases the new HD Radio units at CES 2012.

http://www.youtube.com/watch?v=FXnLHwC1xG0&feature=endscreen&NR=1

Thanks for that good video.

I am looking for a second HD tuner and maybe a table radio or two.

The units on eBay and Amazon seem a few years old. Any advances in the technology?

What's new or where can I look to find a recent discussion?

My Sony, slightly modified, is still chugging along really nicely. But this discontinued model is selling for $200-300 on eBay! Just bought the big Winegard 6055P to update my little Winegard which gets PBS-HD half the time.

Thanks.

Ben

This last weekend I was just outside of Buffalo NY for a family function. Took along the trusty palm sized Insignia HD Radio...

What was fascinating was how it handled intermodulation.

Two stations, that each had HD streams (WBLK was one of them, can't remember the other), were creating intermods here and there on the dial (checked and confirmed content of each station) and found that ONLY the FM signals were part of the mix. At no time did the radio attempt to decode an HD stream or drop into HD Radio mode...

Interesting....

Cameron

I wonder how the famous Sony would handle it?

Got a message from eBay minutes ago about a Sony for sale for $500 - most were bought for like $80.

Ben

Depends on how good the front end is.

That Insignia falls apart in downtown Toronto... Lots o' intermod...

It intermod's here too, but not as severe... And when WTSS (102.5MHz) from Buffalo had that incident where the FM went down, but the HD stayed up, if I found a sweet spot for the intermod, it would take out the HD being received...

In Toronto, my non-HD radio, the Grundig Traveller II G8 just carries on as if nothing is amiss.... Everything comes in just great.

An interesting mix of reception issues for sure.

One humorous but serious side effect of having dual patterns, one for the standard FM signal and another for the HD signal is brought into rather sharp focus when I ride the GO bus from Hamilton to Toronto Union station. AVR (106.5MHz) Toronto, and WYRK, Buffalo are co-channel. Listening to AVR as I pass through the corridor from Oakville past Mississaugua to Toronto, there are spots where AVR still has FM capture, but the HD switches to WYRK, often without warning. With WYRK being current Country in format, it's kinda jarring... :-)

Cameron

With WYRK being current Country in format, it's kinda jarring... :-)

What type of music were you listening to? Not everyone in Canada knows what 106.5 Toronto is. ;)

^^^ AVR (originally Aboriginal Voices Radio, now they generally say "Voices" or "Voices Radio") usually have a wide and varied format. The music can consist of current pop to rock to native current music to spoken work programming. No "Country" is generally heard.

You have an AVR affiliate in Ottawa also. How often they are the same I'm not sure. Last time I visited Ottawa, they were quite different... Roughly a year ago...

The proximity to Buffalo and these co-channel stations still defies logic in their assignments.

Cameron