New Car Purchase with Upgraded HD Radio

[stewie]

My wife and I recently purchased a 2016 Acura MDX.

We upgraded to the technology package +$2k which includes an HD Radio. No, we did not upgrade the package for HD but it's part of the package so my wife now has HD in the car. My first thoughts.

- Bummer the stock radio on the MDX (considered a luxury vehicle) doesn't have an HD radio standard.
- The radio antenna itself leaves a lot to be desired the HD reception itself is not great.

Considering HD was an upgrade and many newer vehicles don't include a decent radio antenna for aesthetic purposes, how much time does HD Radio really have left?

 

[TheBigA]

Considering HD was an upgrade and many newer vehicles don't include a decent radio antenna for aesthetic purposes, how much time does HD Radio really have left?

If you don't have a decent antenna, AM & FM won't come in well either.

Sirius is standard, and only 8% of the potential audience chooses to pay for the service. They seem to be OK.

 

[stewie]

If you don't have a decent antenna, AM & FM won't come in well either.

Sirius is standard, and only 8% of the potential audience chooses to pay for the service. They seem to be OK.

You helped re-enforce my point. If only 8% of the potential audience pays for Sirius/XM (and they're doing alright) then imagine how HD radio would be catching on if it was standard. 100% of the potential audience reached, no silly fees. HD Radio doesn't seem to be doing OK, specially when stations in my market have decided to just turn it off.

 

[TheBigA]

You helped re-enforce my point. If only 8% of the potential audience pays for Sirius/XM (and they're doing alright) then imagine how HD radio would be catching on if it was standard.

I agree. But Sirius is paying car companies a huge amount of money to make it standard. So that's the only reason why it's standard.

 

[stewie]

I agree. But Sirius is paying car companies a huge amount of money to make it standard. So that's the only reason why it's standard.

And that's the part I didn't know. Makes sense.

 

[landtuna]

- The radio antenna itself leaves a lot to be desired the HD reception itself is not great.

My Genesis has a Lexicon entertainment center (which includes HD radio) and I have had no issues with dropped signals at all. Of course, I live in the Sonoran Desert and my metro area doesn't have a ton of tall buildings. The only "obstacle" we have here is distance but I have kept an HD signal alive for almost 80 miles where there were no tall mountains to block it. That is just about the same as analog FM.

 

[DaveBayArea]

My Genesis has a Lexicon entertainment center (which includes HD radio) and I have had no issues with dropped signals at all. Of course, I live in the Sonoran Desert and my metro area doesn't have a ton of tall buildings. The only "obstacle" we have here is distance but I have kept an HD signal alive for almost 80 miles where there were no tall mountains to block it. That is just about the same as analog FM.

So your stations are 100KW ERP and probably no 1st adjacent interference, right? I've heard that HD works great in Texas and Oklahoma, now (I suspect) in Arizona. So it seems like maybe the system itself isn't as bad as people have made it out to be, it's just that it doesn't work well in areas where the FM band is more congested. That's where there seem to be more issues with HD reception dropouts and analog interference.

Dave B.

 

[KB1OKL]

If you don't have a decent antenna, AM & FM won't come in well either.

Sirius is standard, and only 8% of the potential audience chooses to pay for the service. They seem to be OK.

My 09 Pontiac has a little stubby antenna, FM/AM and XM all come in well, wouldn't count on HD radio coming in anywhere near as good as analog FM, but you already knew that didn't you?

 

[tomservo]

Let's face it - antenna design for terrestrial radio is an afterthought for automakers. The traditional whip is considered an ugly eyesore to designers (and probably most customers, too).

With HD's chronically low power levels in many markets, it doesn't stand much of a chance of there are any compromises in antenna or reciever design.

The only reason this doesn't affect GPS and satellite radio is those antennas already have tiny footprints.

Of all the vehicles I've driven in my relatively short life, the only one with a stealth antenna system that seemed to work exceptionally well was in a Nissan with two separate antennas in the front and back windows. The "diversity antenna" radio in it worked very well.

 

[Kelly A]

Let's face it - antenna design for terrestrial radio is an afterthought for automakers. The traditional whip is considered an ugly eyesore to designers (and probably most customers, too).

Antennas may not be as good as they could be, but from the manufacturers perspective they are hardly an afterthought, at least for FM and GPS. AM antenna design has less emphasis, mainly because less and less listeners have even used AM in their cars. Remember also, 1/2 wavelength of broadcast radio around 5' for FM and 200' for AM radio. Making an efficient receive antenna for broadcast that doesn't look like crap is difficult, to say the least.

With HD's chronically low power levels in many markets, it doesn't stand much of a chance of there are any compromises in antenna or reciever design.

Not sure why you say it doesn't stand a chance. As many have reported, including myself, FM HD coverage consistently replicates the 'city grade' coverage of stations that use it. Many of the negative comments here regularly talk about AM and FM HD as if they were the same, they're not. The way FM HD is broadcast is completely different technically than AM. That, and HD has been in use for 14 years. I think the predictions of FM HD's demise have pretty well been proven wrong by now.

The only reason this doesn't affect GPS and satellite radio is those antennas already have tiny footprints.

1/4 wave at GPS frequencies are a couple inches.

 

[rbrucecarter5]

Antennas may not be as good as they could be, but from the manufacturers perspective they are hardly an afterthought, at least for FM and GPS. AM antenna design has less emphasis, mainly because less and less listeners have even used AM in their cars. Remember also, 1/2 wavelength of broadcast radio around 5' for FM and 200' for AM radio. Making an efficient receive antenna for broadcast that doesn't look like crap is difficult, to say the least.

A 60 inch whip, bottom loaded to make its electrical length 20 feet is barely in the electrical efficiency zone for an AM antenna. Ham radio people who have mounted this configuration on their car report up to 600 mile AM reception in the daytime. That would give AM HD a chance of working fairly well on local stations anywhere there are not power lines beside the road.

 

[Kelly A]

A 60 inch whip, bottom loaded to make its electrical length 20 feet is barely in the electrical efficiency zone for an AM antenna. Ham radio people who have mounted this configuration on their car report up to 600 mile AM reception in the daytime.

Oh yes I'm sure auto manufacturers are interested in putting even a 60" whip with a giant coil on their new cars to receive AM. Especially when fewer and fewer are listening to AM. Give me a break.

That would give AM HD a chance of working fairly well on local stations anywhere there are not power lines beside the road.

Or under overpasses, or in buildings, or near a noisy poll hog, etc.. But a 60" whip, no matter how big the loading coil is, wouldn't be very efficient at 160m amateur or the AM broadcast band.

 

[rbrucecarter5]

Oh yes I'm sure auto manufacturers are interested in putting even a 60" whip with a giant coil on their new cars to receive AM. Especially when fewer and fewer are listening to AM. Give me a break.



Or under overpasses, or in buildings, or near a noisy poll hog, etc.. But a 60" whip, no matter how big the loading coil is, wouldn't be very efficient at 160m amateur or the AM broadcast band.

I don't think you noted the sarcasm ----

Electrical efficiency for an antenna starts at about 1/20 the wavelength of the station. That doesn't mean it will make a good antenna, it just means it starts acting as an antenna. Below that threshold, antenna sensitivity takes a nose dive. So technically the hams are correct. Wavelength at 1 MHz = c/f, or 300 meters or 984 feet. So 1/20th is 49 feet. If the loading coil can add 44 feet of electrical length to a 5 foot whip, it crosses that threshold of efficiency. Even though most of the electrical length is functionally useless - being tied up in the coil. The hams have posted Youtube videos of their claim, they do get impressive results. With car radios have way too much RF gain to compensate for the ridiculously short whip, putting a real quarter wave of wire on the antenna input would probable overload the radio. A very short 1/20 wavelength antenna producing good results is plausible. If you are in a rural area with little interference, and don't care how the antenna looks on your car, it is an option to bring AM into tough reception areas.

 

[stewie]

So your stations are 100KW ERP and probably no 1st adjacent interference, right? I've heard that HD works great in Texas and Oklahoma, now (I suspect) in Arizona. So it seems like maybe the system itself isn't as bad as people have made it out to be, it's just that it doesn't work well in areas where the FM band is more congested. That's where there seem to be more issues with HD reception dropouts and analog interference.

Dave B.

Being located in Sacramento CA, we suffer from a tremendous amount of co-channel and first adjacent interference. Simply put, there's a signal on almost every frequency on the FM band in this market. Couldn't agree more about topography. I notice far different behavior when driving in the Bay Area versus Sacramento.

 

[rbrucecarter5]

Being located in Sacramento CA, we suffer from a tremendous amount of co-channel and first adjacent interference. Simply put, there's a signal on almost every frequency on the FM band in this market. Couldn't agree more about topography. I notice far different behavior when driving in the Bay Area versus Sacramento.

Based on skip events the last couple of days, I can say that a first adjacent will wipe out HD if the received power is above the power broadcast on the HD sideband. Best argument yet for an HD power increase, but I doubt it would help much in an area where signals fluctuate - given the lock time of HD signals.

 

[Kelly A]

Based on skip events the last couple of days, I can say that a first adjacent will wipe out HD if the received power is above the power broadcast on the HD sideband. Best argument yet for an HD power increase, but I doubt it would help much in an area where signals fluctuate - given the lock time of HD signals.

Skip events effecting first adjacent FM channels? Since when? Or are you mixing up AM and FM-HD again Bruce? There is no allowable AM-HD power increase possible or even that has been talked about. The station licensed power for AM-HD includes the HD sidebands, just like with analog AM sidebands. Back in January of 2010, the Commission allowed FM stations to increase their HD ERP to 10% of the analog signal.

 

[DaveBayArea]

Skip events effecting first adjacent FM channels? Since when?

Since he called them "events" I read that to mean tropospheric ducting & sporadic E propagation.

Dave B.

 

[Kelly A]

I got that too. That's what was confusing with his statement, because I've yet to have heard where distant co-or adjacent channel FM HD stations have created interference to each other that limited HD reception in situations of VHF ducting or propagation.

 

[tomservo]

Hopefully I'm not falling into the confusion trap here but skip on FM definitely affects HD reception in my market. Because we are on the coast it happens quite a lot in the summer.

Just this morning I could not maintain lock on two different broadcasts due to enhanced reception conditions. Stations from Baton Rouge and Lafayette were wiping out more local stations.

It played havoc with RDS decoding as well.

On the positive side, I heard a few stations I'd never heard before and got to listen to WTIX out of New Orleans like it was a local for several hours.

 

[rbrucecarter5]

Skip events effecting first adjacent FM channels? Since when? Or are you mixing up AM and FM-HD again Bruce? There is no allowable AM-HD power increase possible or even that has been talked about. The station licensed power for AM-HD includes the HD sidebands, just like with analog AM sidebands. Back in January of 2010, the Commission allowed FM stations to increase their HD ERP to 10% of the analog signal.

Nope, I was talking about FM. AM-HD is, of course, affected too by first adjacents, but since AM-HD is effectively dead - station count down to 169 - I don't think it even warrants discussion any more.

I am very surprised you would be unaware of first adjacent FM - yes FM - affecting HD. It is very simple to understand why. I tuned to 106.9, expecting the HD to lock in. It never did. Tune down one frequency and there was a 106.7 skipping in from 180 miles away. Since FM-HD puts its sidebands on the first adjacent frequency, and that frequency was occupied by a strong signal, HD reception is jammed. End of story. Why would that be difficult for you to understand? FM is governed by capture ratio - the strongest signal will dominate. A 10% HD sideband power of 10 kW will do nothing to help if the atmosphere is bouncing in a 100 kW signal at full power.