One could argue that the USA did do a gradual switchover.
A series of deadlines were set for stations to begin digital transmission. The largest cities were required to begin digital first, gradually rolling to the smaller communities. The station I work for has been broadcasting a digital signal since 2002.
Viewers could have begun buying digital receivers years ago. (and many did.)
What was supposed to happen in two weeks was the final shutdown of the analog transmitters.
(do note that in the USA common transmitter sites are relatively rare. (by comparison to European countries) Here in Nashville, there are eight different transmitter sites serving 13 stations. That situation is not unusual. It's not a matter of converting one site from analog to digital and being done with it.)
I don't know where he got that. A paragraph of the original bill explicitly allowed stations to sign off at any date earlier than June 12th provided they meet notification requirements already in the FCC regulations.
There is no change in that paragraph in the new bill.
I haven't read the entire new bill but I'm not sure there's any difference between the old and new bills. I think all they're doing is running it through the regular committee system so it only needs a 1/2 majority, not 2/3, to pass.
You have to announce termination 30 days in advance.
The grey area, as I see it, is that the rules are changing in midstream. Today, if you plan to go off on 2/17, you don't need to notify anyone -- your analog license is automatically canceled on 2/18.
After this bill is enacted (presumably sometime next week) you have to give 30 days' notice.
But there are fewer than 30 days before 2/17.
Several hundred stations have already given notice of their intent to shut down their analogs on schedule, on the 17th. Most did not give notice 30 days in advance though - as a delay wasn't on the table that early. There was no reason to believe any further action would be required of stations which wished to go off in February.
I have to presume the FCC will relax the notice requirement for those stations that begin notification promptly (within a day or two) of the enactment of this bill.
I would venture a guess what triggered this was problems in the DTV coupon program.
This program offers each household up to two coupons. (in the form of cards, similar to a debit card) Each coupon could be redeemed for US$40 off the price of a digital receiver. Digital receivers are selling for around US$60-65.
The coupon program has more or less run out of money. "more or less" because they're finding many, many coupons are being ordered but never redeemed. They do have an expiration period. (90 days) I suppose the theory is that if the analog shutdown is delayed, more unused coupons will expire and more money will be available to issue more coupons and more viewers can use those coupons to get converted in time.
That said, most Americans are more than willing to pay more than $60 every month for cable or satellite service, it seems unlikely that a one time payment of $60 for a converter box is going to be a problem for most families.
(for those families for whom $60 is a problem, I have sympathy... although they really should have acted sooner...)
There is also some concern that viewers in some places are having trouble receiving all the channels they were getting in analog. Problem is, in many cases that's because:
The digital signals are suffering interference from analog transmitters.
Or, they're having to operate on reduced power to avoid interfering with analog service.
Or, the station plans to use its current analog antenna for its permanent digital service -- is currently on a lower interim antenna -- and of course cannot switch to full power until it can turn its analog transmitter off.
Of course delaying the analog shutdown only delays the delivery of a full digital signal to these viewers!
See Sec. 4, paragraph (a) which states in part: "Nothing in this Act is intended to prevent a licensee of a television broadcast station from terminating the broadcasting of such station's analog television signal (and continuing to broadcast exclusively in the digital television service) prior to the date established by law under section 3002(b) of the Digital Television Transition and Public Safety Act of 2005 for termination of all licenses for full-power television stations in the analog television service (as amended by section 2 of this Act) so long as such prior termination is conducted in accordance with the Federal Communications Commission's requirements in effect on the date of enactment of this Act,.."
(typical government wordiness)
What it means is that before this bill was introduced, stations could sign off their analogs before Feb. 17th upon giving 30 days notice to the FCC and the viewers. Should the bill pass into law, paragraph (a) ensures they can still sign off before June 12th, again provided they give 30 days notice.
Several hundred stations have already given such notice. Including most of the major-network affiliates in Nashville, New Orleans, and Wichita among other cities.
1. you'll [generally[ need a decent UHF antenna... some channels are in the VHF range, but unless you're in one of the oddball U.S. areas, a UHF antenna optimized for reception from 450MHz to 800MHz will do just fine...
Note that many stations will change channels when the analog stations go off next February. Even if all your local stations are UHF today, some may not be in a few months. For example, all DTV in Seattle is UHF today. Next February, KCTS (PBS), KSTW (CBS), and KCPQ (Fox) will move to VHF channels 9/11/13.
Luckily, often antennas designed for UHF only will actually work for VHF channels 7-13. Amplified UHF antennas are less likely to work for VHF.
Unfortunately, in a few cities VHF channels 2-6 will be used. Philadelphia (ABC), Albany (NBC), and San Antonio (CW) are probably the largest. A UHF-only antenna is not likely to work here.
What proportion of viewers in Scandanavia receive their TV over antenna? (vs. cable or satellite?)
I fear broadcasters over here believe everyone is watching on cable or satellite and so won't be affected when the analog transmitters are switched off.
I don't think that would fly here in the U.S.. Chronic speeders here already believe speed limits are artificially low and enforced for the sole reason of increasing revenue without having to raise taxes. Tying fines to income will serve mostly to reinforce this belief.
I think it's time to give up on fines as a means of deterring the most serious violators. I think we should send people to jail if they're caught driving more than 30km/h (20mph) over the limit. Or if they're caught tailgating in an attempt to intimidate other motorists into speeding. Lock them up (in some kind of inexpensive, low-security "traffic camp") for a randomly chosen day or two.
Largely, the concern is that the unlicensed devices will not accurately determine whether a channel actually is unused. Recent tests showed that test devices would wrongly assume a channel to be free for use 19% of the time when that channel was actually occupied by a usable analog TV signal. Of course, analog TV goes away in about 18 months, so maybe we shouldn't worry about it -- but the figure was much worse for digital TV.
58% of the time, the devices would wrongly assume a channel was free for use when it was in fact occupied by a useful digital TV signal.
I think a fair part of the problem is that people are willing to use considerably larger antennas for TV reception than they're willing to use with wireless short-haul modems. A TV receiver with an attic UHF Yagi antenna attached will deliver a clean picture from a digital TV station that's way too weak to receive on a wireless device with an internal antenna.
Another recent FCC estimate (which I can't find right now) states that approximately 20% of U.S. homes do not have cable or satellite. It also found that a large number of homes that do have cable also have one or more TVs that are not connected to the cable.
One might argue that *approving* these devices would prop up the stranglehold cable companies have on the consumer...
These were preliminary tests of what the FCC called "Prototype TV-Band White Space Devices". "White Space" referring to unused TV channels. What the FCC was testing was the ability of these devices to determine that a given TV channel was unused. Two devices from different manufacturers were tested. (the FCC documents don't specify which device is Microsoft's) They were not complete systems - one didn't even contain a transmitter - the test was to determine whether the units could accurately determine whether it was safe to use a channel.
It didn't work very well.
Prototype A, tested at a variety of locations in homes in the Washington, DC area, falsely detected a channel as occupied (and unavailable for use) 15% of the time. Far more disturbingly, it falsely detected a channel as unused (and available for use) 58% of the time when a useful digital TV signal was present on that channel. While analog TV is likely to go away in the U.S. before these devices can be brought to market, they did falsely find a channel to be clear of useful analog signals 19% of the time.
Other tests with the one that did contain a transmitter found that interference was caused to digital reception to a distance of 87m - and that with the wireless device at reduced power.
Point being, that as currently designed, these devices would wipe out digital TV reception, forcing owners - and their neighbors - to subscribe to cable or a satellite service. FCC figures show that 20% of homes still rely on over-the-air TV reception, and millions of homes that already have cable also have one or more sets that aren't connected. Such interference would not be trivial.
Personally, I think this kind of thing is going to prove problematic. To reliably detect the presence of a TV signal strong enough to be viewed, your "white space device" is going to need an antenna at least as good as what's attached to the TV set - and as far from noise-spewing computers (and other digital devices) as the antenna attached to the TV set. Consumers have a hard enough time accepting an "ugly" antenna on their TV. Microsoft & competitors are going to have a hard time selling these boxes if they have to have an antenna too.
On any kind of cell phone, you're only connected to one cell at a time.
Let's say your phone is connected to Cell A and is talking on channel 375. You aren't using Cell B. But you are using channel 375. If Cell B tries to assign channel 375 for someone else's call, your phone is going to interfere with theirs. If you're flying at 15,000 feet, you're only going to tie up one cell at a time -- but you're going to tie up channel 375 for as far as 100km or more.
World's tallest building is what, 509m? I'm not a pilot but if I'm not mistaken, in the US aircraft are not permitted to fly below 600m except for takeoff and landing. Commercial planes fly a LOT higher than that.
Mountains get a lot taller, with Everest approaching 10,000m. I don't imagine there are a whole lot of cell towers surrounding Everest though. Even if there were, there aren't a whole lot of people climbing Everest. You could have the problem on a smaller scale in a place like Mt. Wilson (1,742m and overlooking Los Angeles) or Sandia Crest. (3,000m overlooking Albuquerque) But again, I think it's probably reasonable to assume the number of people flying into/out of LAX on any given day well exceeds the number driving to the top of Mt. Wilson.
Aircraft over populated areas are simply a completely different class of problem.
Actually IMHO that's a pretty good solution. Phones are designed to back off their power to the minimum necessary for a good connection - so if they're right next to the cell they should be radiating next to nothing - and it would be practical to shield the cabin enough to prevent problems on the ground.
The antennas inside the plane don't need to be that sensitive (since the phones are really close), the picocell doesn't need much power, and things don't have to be protected from the elements since the cabin is already doing that. I don't think it would be at all impossible to support multiple standards.
But you would still have to have a way to get the calls linked between the picocell and something on the ground. Technically simple, but probably horribly expensive, especially when filtered through a monopoly.
Yep. The coverage of even a small, low-powered VHF radio increases dramatically when operated from an aircraft.
In the U.S., Class A FM broadcasting stations are limited to a power of 6,000 watts at a maximum antenna height of 100m. Higher antennas are allowed if the power is reduced to compensate. At an antenna elevation of 600m, power must be reduced to only 150 watts (?!) to achieve the same distance coverage. Translate those figures to a cell phone with a rated power of no more than 3 watts, and you're talking about limiting power to 0.08 watt at 600m.
Of course, commercial aircraft fly a LOT higher than 600m!
The cellular network has far more subscribers than it has channels. To work, it depends on the ability to reuse a channel throughout the service area. If I place a phone call from my home 40km northwest of Nashville, the same channel can be reused in downtown Nashville, and on the city's west side, and in Donelson, and Brentwood, and Smyrna, etc., etc... My phone, about 1.2m off the ground, has a range of only about 6km.
If I place that call from an airplane flying 8,000m above my home, every base station in the greater Nashville area can receive my signals. Now, "my" channel cannot be reused at all.
If it were just me, that wouldn't be a problem. If it were, say, 10% of the passengers on each flight - well, I don't think it's hard to see how that could use up all available channels in a hurry. New channels aren't cheap. Nextel is paying to replace almost *all* the microwave remote broadcast equipment in use by U.S. TV stations, so they can free up some remote broadcast spectrum for use as cellular-telephone channels.
Here's an idea: allow calls from aircraft, but allow cellular providers to charge enough extra for airborne calls to cover their costs in adding more channels. I'll bet after the next billing cycle, the number of calls made from aircraft would plummet!
I work evening shift - I don't report to work until 2pm.
One morning, an important manager decided to redo her office, moving her desk to the other side. The patch cord for her Ethernet connection was too short. They couldn't wait for 2:00 when I came in. (and apparently didn't bother trying to contact me at home)
So the tech who moved her decided to splice in some more cable. He didn't know how to crimp on RJ-45 plugs, but he found a length of cable that already had a RJ-45 on it. He lopped the connector off the other end and spliced it to the existing patch cord with "Dolphin" splices.
It actually would have worked, except...
that the length he found with the RJ-45 already installed was silver satin. There was only about ten feet of it, but it killed her circuit *DEAD*. No connection whatsoever at any speed. It was pinned properly - the tester we had at the time (which only checked continuity) said the cable was OK - but it sure didn't pass even 10MHz...
But Tesla didn't broadcast, did he? (at least not on purpose)
There are multiple definitions of the "invention" of radio, depending on exactly what you consider "radio" and what you consider "invented". I don't know that it's even reasonable to say anyone invented radio -- noise bursts emitted from lightning strikes (and stars) long predate mankind, let alone any actions of human inventors. It might be more accurate to say radio was discovered, and I might suggest Heinrich Hertz was the one who discovered it.
Others - Fessenden, Marconi, Herrold, etc., etc. - discovered, or invented, ways of applying radio. As another post suggests, there are multiple definitions of "broadcast". Fessenden's transmissions may have been the first broadcasts of voice, but back in 1909 station 9XM at the University of Wisconsin broadcast crop reports using Morse Code. (apparently enough farmers in rural Wisconsin were radio hams - knew Morse - to make the effort worthwhile) On that basis, 9XM claims to be the first station to broadcast. They're now WHA 970 AM.
(as a proud Madisonian I probably shouldn't say this, but 9XM almost certainly was NOT the first station to broadcast Morse signals. A "CQ" transmission has been part of ham radio since the beginning; a "CQ" is a broadcast to all radio hams, indicating that you're looking for someone to start a conversation with. CQ certainly predates 1909.)
KDKA claims to be the first broadcast station - it appears it was the first station to take out a license for the express purpose of broadcasting, but it certainly wasn't the first station to actually broadcast. The first station to hold a broadcasting license was another Westinghouse station - WBZ Boston, I think, or maybe KYW Chicago.[0] At the time of its first broadcasts, KDKA held a "special land station" license - a license of a type issued to all stations that weren't hams and weren't involved in ship-to-shore communications.
It might surprise folks to know that commercial radio broadcasting existed for six years before the first advertisement was sold.
[0] I realize KYW is in Philadelphia. It didn't get to Philly until 1934.
But you're right, the programming stinks. At sunset when I can't get the NPR station anymore, I only listen to AM at the top of the hour when someone might (or might not...) run the required station identification. Nothing else is worth listening to.
I did once receive two British stations here in the Nashville area, transmitted direct from the UK.
kdka is a "clear channel" station. Such stations are allowed to increase their power at night, and the signal is refracted by the ionosphere.
"clear channel" stations are not allowed to increase power at night. While I haven't specifically mined the FCC database, I can say with considerable confidence that there are fewer than ten AM stations in North America that run more power at night than during the day.
However, "clear channel" stations are not required to *reduce* power at night. Most other stations are, and/or are required to switch to a directional antenna that concentrates all their power in a specific direction.
Technically, "clear channel" refers to the frequency, not to any specific station. For example, 720KHz is a "clear channel", and in theory any station operating on that frequency could call itself a "clear channel" station. Many do.
"clear channel" stations are divided into three classes, A, B, and D. Only one Class A station can exist on a frequency, and that's the dominant station most people think of when they think of a "clear channel" station. This station is allowed to operate 50,000 watts non-directional day & night, and is not required to protect any other station from interference. All other stations on the frequency must protect the Class A station.
For example, on 720KHz, WGN in Chicago is the Class A station. KDWN in Las Vegas is one of several Class B stations on 720; KDWN runs 50,000 watts 24/7, but is required to switch to a directional antenna at night, limiting the amount of power radiated in the direction of Chicago to maybe two or three dozen watts. (I think you can reasonably assume the KDWN transmitter is northeast of Las Vegas!).
Class D stations are those that are not allowed to operate at all at night, or are limited to nighttime powers less than that required for a new station. (generally, less than 250 watts; sometimes as little as one watt. No new Class D stations are being authorized.) An example of a Class D station on 720 is WGCR in western North Carolina, which goes off the air completely at sundown to protect WGN from interference.
Use the best FM radio you have. In most cases, this is your car radio. AM/MW doesn't work.
Find the most open frequency possible. It's best if you can find a frequency where you hear only noise, but meteor-reflected signals can override weak stations, so don't give up if you can't find a completely open spot. In the U.S., be careful that you don't use an "open" frequency that's right next to a strong local station. It might not actually be open.
Listen!.
You'll hear a lot of static, but every once in awhile, you'll hear a brief burst of signal. This is (probably) a distant station's signal bouncing off the ionized trail left by a meteor. Short bursts can be just a "ping"; long ones have lasted as long as a minute! (1-5 seconds is most common) Stations can be between 500 and 2000km distant. If you're really lucky you might even hear some identifying information, like a local commercial.
This also works with analog TV, primarily on Band I (in the Americas: "low-band VHF" channels 2-6). It's unlikely a burst will be long or stable enough to allow digital reception. And, of course, you have to have an antenna on your TV - the only way the meteor shower is going to affect your cable or satellite reception is if a meteor hits the satellite!
It certainly wouldn't be the first time the current FCC has ignored the facts to implement what lobbyists were telling them to do. Admittedly, sometimes Congress gets into the act too. Looking at strictly technical issues, we've seen:
IBOC digital radio, where a spurious-emission limit intended to cover intermittent splatter like cymbal crashes and the crack of a baseball bat is used to justify digital sideband hash that's there 100% of the time. (and causes severe interference to existing analog service)
Low-power FM, where you can't have a station on 90.5 in West Memphis if it originates its own programs, because it might interfere with existing stations on 89.9 and 91.1. But if the station instead relays a St. Louis station, not only does it not interfere anymore (?!) but it can run 2.5 times the power & operate even closer in frequency to the 89.9 and 91.1 stations.
Broadband over power lines, which like IBOC uses interference exemptions intended to cover brief, intermittent, and unintentional transmissions to justify signals that are present 100% of the time and cause severe interference to existing stations. (it's also touted as a way of getting broadband to unserved rural homes - but to date has been deployed only in well-to-do urban suburbs...)
When I had my first experiences with the Commission - getting a ham radio license back in 1973 at age 14 - the FCC was a respected organization. Everyone expected their technical rules to be based on real science. It sure isn't that way anymore!
It would be interesting to see a link on this "phased array tech". Phased arrays have been around for a long time - the first one used in broadcasting was installed in Florida back in 1932. They do allow multiple transmitters to share a frequency, but there are limits.
You still can't have two stations covering the same place on the same frequency. To use a phased array to make two stations possible on the same frequency, each station has to sacrifice some of its coverage area.
The technology has made thousands of additional AM stations and a handful of additional FM and TV outlets possible. It doesn't come anywhere near creating unlimited spectrum though.
I have a HD radio, and it definitely doesn't sound *worse* than analog. Except for one station that has it set up wrong.
Can't say that it sounds any *better* either. By the time a station (either AM or FM) is strong enough for the digital to work, it's strong enough to deliver a nice clean analog signal. The FM stations, I simply cannot tell the difference. The one AM station, if I listen real close i can hear artifacts but you have to listen for them to find them - most listeners would never notice.
...the options that will soon be available will make XM look like a pretty silly business model...
on the other hand... all the XM/Sirius formats work everywhere. If you like classic country, to get it over WSM-HD you'd better live in the Nashville metro area. Get more than 120km from Music Row, and it'll be gone. The classic country channels on Sirius/XM work everywhere in North America.
120km is probably rather optimistic. With my $300 HD radio, I have to have a 80m outdoor antenna to get the HD signal of a 50kw station 30km away. That'd improve once we drop hybrid mode for all-digital & increase the digital power -- but I don't expect to live long enough to see that happen. Too many analog radios out there.
Right now, AM (MW) stations are not allowed to run HD at night. The HD signal is carried in the two adjacent channels. (for a station on 1510KHz, the HD signals are carried in 1495-1505 and 1515-1525KHz) This results in severe interference to, in this case, 1490, 1500, 1520, and 1530. The first-adjacents (1500 & 1520) are not assigned for use within the coverage area of a 1510 station. 1490, on the other hand, is a problem. I've heard interference from a 1510 HD station within the city officially served by a 1490 station, about 60km from the 1510 transmitter -- and less than 6km from the 1490 transmitter. (I may have heard the interference in places where I could see the 1490 transmitting antenna!)
If HD AM is allowed at night, definitely distant reception will end; if you don't live in a large city you may lose most of your nighttime AM service. (at my home ~50km from Nashville, WSM is probably the only AM station I'll get at night in a fully-deployed HD world) That aside, it looks like a lot of local service will also be impacted.
The story isn't quite as bad on FM. The HD signals are carried only in the first adjacent channels. (95.3 & 95.7 for a HD station on 95.5) In some cases this will still be a problem, especially in deep-suburban areas or on cheap radios.
I am not particularly impressed by the HD coverage either. I have to search for a "sweet spot" to get the HD of an 80kw station 50km away with an indoor antenna. That's not necessary with analog. (worth doing, for the excellent digital-only programs on WPLN-HD2) Again the coverage will probably improve in all-digital mode, if we ever get there...
This system was designed first & foremost to protect local stations from competition, It's got a long way to go before it provides reliable replacement service for analog.
Doug S. (TV engineer & follower of radio tech trends)
Strangely enough this is not the first application of Morse Code in the tech world... Older UPSs have used Morse to signal error conditions.
They sent considerably more slowly than the folks on TV, and a sticker on top of the UPS showed what each code pattern meant.
It really made a fair amount of sense in context. Morse is a code that's extremely easy to generate by computer (even on a PIC with limited power), and can be read by ear by a skilled operator. For slow speeds and the limited vocabulary of a UPS, it wouldn't take much skill to read the Morse well enough to know what's going on. And the hardware costs of doing this in a UPS (or similar device) are zero, if you're going to have an audible error annunciator anyway...
Anyway, I think the idea of using Morse to send text messages is an excellent one. It's a whole lot easier to manipulate a single button in an timed manner than it is to find the right key on a 12-button pad and *then* manipulate it in a timed manner...
I believe anyone who can learn to type can learn to send Morse at at least half their typing speed. That's a whole lot faster than most of us can text!
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One could argue that the USA did do a gradual switchover. A series of deadlines were set for stations to begin digital transmission. The largest cities were required to begin digital first, gradually rolling to the smaller communities. The station I work for has been broadcasting a digital signal since 2002. Viewers could have begun buying digital receivers years ago. (and many did.) What was supposed to happen in two weeks was the final shutdown of the analog transmitters. (do note that in the USA common transmitter sites are relatively rare. (by comparison to European countries) Here in Nashville, there are eight different transmitter sites serving 13 stations. That situation is not unusual. It's not a matter of converting one site from analog to digital and being done with it.)
I don't know where he got that. A paragraph of the original bill explicitly allowed stations to sign off at any date earlier than June 12th provided they meet notification requirements already in the FCC regulations.
There is no change in that paragraph in the new bill.
I haven't read the entire new bill but I'm not sure there's any difference between the old and new bills. I think all they're doing is running it through the regular committee system so it only needs a 1/2 majority, not 2/3, to pass.
You have to announce termination 30 days in advance.
The grey area, as I see it, is that the rules are changing in midstream. Today, if you plan to go off on 2/17, you don't need to notify anyone -- your analog license is automatically canceled on 2/18.
After this bill is enacted (presumably sometime next week) you have to give 30 days' notice.
But there are fewer than 30 days before 2/17.
Several hundred stations have already given notice of their intent to shut down their analogs on schedule, on the 17th. Most did not give notice 30 days in advance though - as a delay wasn't on the table that early. There was no reason to believe any further action would be required of stations which wished to go off in February.
I have to presume the FCC will relax the notice requirement for those stations that begin notification promptly (within a day or two) of the enactment of this bill.
I would venture a guess what triggered this was problems in the DTV coupon program.
This program offers each household up to two coupons. (in the form of cards, similar to a debit card) Each coupon could be redeemed for US$40 off the price of a digital receiver. Digital receivers are selling for around US$60-65.
The coupon program has more or less run out of money. "more or less" because they're finding many, many coupons are being ordered but never redeemed. They do have an expiration period. (90 days) I suppose the theory is that if the analog shutdown is delayed, more unused coupons will expire and more money will be available to issue more coupons and more viewers can use those coupons to get converted in time.
That said, most Americans are more than willing to pay more than $60 every month for cable or satellite service, it seems unlikely that a one time payment of $60 for a converter box is going to be a problem for most families.
(for those families for whom $60 is a problem, I have sympathy... although they really should have acted sooner...)
There is also some concern that viewers in some places are having trouble receiving all the channels they were getting in analog. Problem is, in many cases that's because:
The digital signals are suffering interference from analog transmitters.
Or, they're having to operate on reduced power to avoid interfering with analog service.
Or, the station plans to use its current analog antenna for its permanent digital service -- is currently on a lower interim antenna -- and of course cannot switch to full power until it can turn its analog transmitter off.
Of course delaying the analog shutdown only delays the delivery of a full digital signal to these viewers!
The original bill didn't require analog stations to stay on until June either.
(if the link breaks, try this PDF link)
See Sec. 4, paragraph (a) which states in part: "Nothing in this Act is intended to prevent a licensee of a television broadcast station from terminating the broadcasting of such station's analog television signal (and continuing to broadcast exclusively in the digital television service) prior to the date established by law under section 3002(b) of the Digital Television Transition and Public Safety Act of 2005 for termination of all licenses for full-power television stations in the analog television service (as amended by section 2 of this Act) so long as such prior termination is conducted in accordance with the Federal Communications Commission's requirements in effect on the date of enactment of this Act,.."
(typical government wordiness)
What it means is that before this bill was introduced, stations could sign off their analogs before Feb. 17th upon giving 30 days notice to the FCC and the viewers. Should the bill pass into law, paragraph (a) ensures they can still sign off before June 12th, again provided they give 30 days notice.
Several hundred stations have already given such notice. Including most of the major-network affiliates in Nashville, New Orleans, and Wichita among other cities.
The proposed new bill (PDF version) contains the same paragraph.
Note that many stations will change channels when the analog stations go off next February. Even if all your local stations are UHF today, some may not be in a few months. For example, all DTV in Seattle is UHF today. Next February, KCTS (PBS), KSTW (CBS), and KCPQ (Fox) will move to VHF channels 9/11/13.
Luckily, often antennas designed for UHF only will actually work for VHF channels 7-13. Amplified UHF antennas are less likely to work for VHF.
Unfortunately, in a few cities VHF channels 2-6 will be used. Philadelphia (ABC), Albany (NBC), and San Antonio (CW) are probably the largest. A UHF-only antenna is not likely to work here.
Shameless self-promotion: there's a list of post-February assignments on my website at http://www.w9wi.com/dtvch/dtvch.html.
What proportion of viewers in Scandanavia receive their TV over antenna? (vs. cable or satellite?)
I fear broadcasters over here believe everyone is watching on cable or satellite and so won't be affected when the analog transmitters are switched off.
I don't think that would fly here in the U.S.. Chronic speeders here already believe speed limits are artificially low and enforced for the sole reason of increasing revenue without having to raise taxes. Tying fines to income will serve mostly to reinforce this belief.
I think it's time to give up on fines as a means of deterring the most serious violators. I think we should send people to jail if they're caught driving more than 30km/h (20mph) over the limit. Or if they're caught tailgating in an attempt to intimidate other motorists into speeding. Lock them up (in some kind of inexpensive, low-security "traffic camp") for a randomly chosen day or two.
http://www.cbc.ca/news/background/crime/street-racing.html
Largely, the concern is that the unlicensed devices will not accurately determine whether a channel actually is unused. Recent tests showed that test devices would wrongly assume a channel to be free for use 19% of the time when that channel was actually occupied by a usable analog TV signal. Of course, analog TV goes away in about 18 months, so maybe we shouldn't worry about it -- but the figure was much worse for digital TV.
58% of the time, the devices would wrongly assume a channel was free for use when it was in fact occupied by a useful digital TV signal.
http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-07-3457A1.pdf
http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-275666A1.pdf
http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-275666A2.pdf
http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-275668A1.pdf
I think a fair part of the problem is that people are willing to use considerably larger antennas for TV reception than they're willing to use with wireless short-haul modems. A TV receiver with an attic UHF Yagi antenna attached will deliver a clean picture from a digital TV station that's way too weak to receive on a wireless device with an internal antenna.
Another recent FCC estimate (which I can't find right now) states that approximately 20% of U.S. homes do not have cable or satellite. It also found that a large number of homes that do have cable also have one or more TVs that are not connected to the cable.
One might argue that *approving* these devices would prop up the stranglehold cable companies have on the consumer...
/ DA-07-3457A1.pdf/ DOC-275666A1.pdf/ DOC-275666A2.pdf/ DOC-275668A1.pdf
These were preliminary tests of what the FCC called "Prototype TV-Band White Space Devices". "White Space" referring to unused TV channels. What the FCC was testing was the ability of these devices to determine that a given TV channel was unused. Two devices from different manufacturers were tested. (the FCC documents don't specify which device is Microsoft's) They were not complete systems - one didn't even contain a transmitter - the test was to determine whether the units could accurately determine whether it was safe to use a channel.
It didn't work very well.
Prototype A, tested at a variety of locations in homes in the Washington, DC area, falsely detected a channel as occupied (and unavailable for use) 15% of the time. Far more disturbingly, it falsely detected a channel as unused (and available for use) 58% of the time when a useful digital TV signal was present on that channel. While analog TV is likely to go away in the U.S. before these devices can be brought to market, they did falsely find a channel to be clear of useful analog signals 19% of the time.
Other tests with the one that did contain a transmitter found that interference was caused to digital reception to a distance of 87m - and that with the wireless device at reduced power.
Point being, that as currently designed, these devices would wipe out digital TV reception, forcing owners - and their neighbors - to subscribe to cable or a satellite service. FCC figures show that 20% of homes still rely on over-the-air TV reception, and millions of homes that already have cable also have one or more sets that aren't connected. Such interference would not be trivial.
Personally, I think this kind of thing is going to prove problematic. To reliably detect the presence of a TV signal strong enough to be viewed, your "white space device" is going to need an antenna at least as good as what's attached to the TV set - and as far from noise-spewing computers (and other digital devices) as the antenna attached to the TV set. Consumers have a hard enough time accepting an "ugly" antenna on their TV. Microsoft & competitors are going to have a hard time selling these boxes if they have to have an antenna too.
The FCC documents: (the 2nd is the most relevant but also the most technical)
http://hraunfoss.fcc.gov/edocs_public/attachmatch
http://hraunfoss.fcc.gov/edocs_public/attachmatch
http://hraunfoss.fcc.gov/edocs_public/attachmatch
http://hraunfoss.fcc.gov/edocs_public/attachmatch
On any kind of cell phone, you're only connected to one cell at a time.
Let's say your phone is connected to Cell A and is talking on channel 375. You aren't using Cell B. But you are using channel 375. If Cell B tries to assign channel 375 for someone else's call, your phone is going to interfere with theirs. If you're flying at 15,000 feet, you're only going to tie up one cell at a time -- but you're going to tie up channel 375 for as far as 100km or more.
World's tallest building is what, 509m? I'm not a pilot but if I'm not mistaken, in the US aircraft are not permitted to fly below 600m except for takeoff and landing. Commercial planes fly a LOT higher than that.
Mountains get a lot taller, with Everest approaching 10,000m. I don't imagine there are a whole lot of cell towers surrounding Everest though. Even if there were, there aren't a whole lot of people climbing Everest. You could have the problem on a smaller scale in a place like Mt. Wilson (1,742m and overlooking Los Angeles) or Sandia Crest. (3,000m overlooking Albuquerque) But again, I think it's probably reasonable to assume the number of people flying into/out of LAX on any given day well exceeds the number driving to the top of Mt. Wilson.
Aircraft over populated areas are simply a completely different class of problem.
Actually IMHO that's a pretty good solution. Phones are designed to back off their power to the minimum necessary for a good connection - so if they're right next to the cell they should be radiating next to nothing - and it would be practical to shield the cabin enough to prevent problems on the ground.
The antennas inside the plane don't need to be that sensitive (since the phones are really close), the picocell doesn't need much power, and things don't have to be protected from the elements since the cabin is already doing that. I don't think it would be at all impossible to support multiple standards.
But you would still have to have a way to get the calls linked between the picocell and something on the ground. Technically simple, but probably horribly expensive, especially when filtered through a monopoly.
Yep. The coverage of even a small, low-powered VHF radio increases dramatically when operated from an aircraft.
In the U.S., Class A FM broadcasting stations are limited to a power of 6,000 watts at a maximum antenna height of 100m. Higher antennas are allowed if the power is reduced to compensate. At an antenna elevation of 600m, power must be reduced to only 150 watts (?!) to achieve the same distance coverage. Translate those figures to a cell phone with a rated power of no more than 3 watts, and you're talking about limiting power to 0.08 watt at 600m.
Of course, commercial aircraft fly a LOT higher than 600m!
The cellular network has far more subscribers than it has channels. To work, it depends on the ability to reuse a channel throughout the service area. If I place a phone call from my home 40km northwest of Nashville, the same channel can be reused in downtown Nashville, and on the city's west side, and in Donelson, and Brentwood, and Smyrna, etc., etc... My phone, about 1.2m off the ground, has a range of only about 6km.
If I place that call from an airplane flying 8,000m above my home, every base station in the greater Nashville area can receive my signals. Now, "my" channel cannot be reused at all.
If it were just me, that wouldn't be a problem. If it were, say, 10% of the passengers on each flight - well, I don't think it's hard to see how that could use up all available channels in a hurry. New channels aren't cheap. Nextel is paying to replace almost *all* the microwave remote broadcast equipment in use by U.S. TV stations, so they can free up some remote broadcast spectrum for use as cellular-telephone channels.
Here's an idea: allow calls from aircraft, but allow cellular providers to charge enough extra for airborne calls to cover their costs in adding more channels. I'll bet after the next billing cycle, the number of calls made from aircraft would plummet!
I'm surprised this worked at all.
I work evening shift - I don't report to work until 2pm.
One morning, an important manager decided to redo her office, moving her desk to the other side. The patch cord for her Ethernet connection was too short. They couldn't wait for 2:00 when I came in. (and apparently didn't bother trying to contact me at home)
So the tech who moved her decided to splice in some more cable. He didn't know how to crimp on RJ-45 plugs, but he found a length of cable that already had a RJ-45 on it. He lopped the connector off the other end and spliced it to the existing patch cord with "Dolphin" splices.
It actually would have worked, except...
that the length he found with the RJ-45 already installed was silver satin. There was only about ten feet of it, but it killed her circuit *DEAD*. No connection whatsoever at any speed. It was pinned properly - the tester we had at the time (which only checked continuity) said the cable was OK - but it sure didn't pass even 10MHz...
But Tesla didn't broadcast, did he? (at least not on purpose)
There are multiple definitions of the "invention" of radio, depending on exactly what you consider "radio" and what you consider "invented". I don't know that it's even reasonable to say anyone invented radio -- noise bursts emitted from lightning strikes (and stars) long predate mankind, let alone any actions of human inventors. It might be more accurate to say radio was discovered, and I might suggest Heinrich Hertz was the one who discovered it.
Others - Fessenden, Marconi, Herrold, etc., etc. - discovered, or invented, ways of applying radio. As another post suggests, there are multiple definitions of "broadcast". Fessenden's transmissions may have been the first broadcasts of voice, but back in 1909 station 9XM at the University of Wisconsin broadcast crop reports using Morse Code. (apparently enough farmers in rural Wisconsin were radio hams - knew Morse - to make the effort worthwhile) On that basis, 9XM claims to be the first station to broadcast. They're now WHA 970 AM.
(as a proud Madisonian I probably shouldn't say this, but 9XM almost certainly was NOT the first station to broadcast Morse signals. A "CQ" transmission has been part of ham radio since the beginning; a "CQ" is a broadcast to all radio hams, indicating that you're looking for someone to start a conversation with. CQ certainly predates 1909.)
KDKA claims to be the first broadcast station - it appears it was the first station to take out a license for the express purpose of broadcasting, but it certainly wasn't the first station to actually broadcast. The first station to hold a broadcasting license was another Westinghouse station - WBZ Boston, I think, or maybe KYW Chicago.[0] At the time of its first broadcasts, KDKA held a "special land station" license - a license of a type issued to all stations that weren't hams and weren't involved in ship-to-shore communications.
It might surprise folks to know that commercial radio broadcasting existed for six years before the first advertisement was sold.
[0] I realize KYW is in Philadelphia. It didn't get to Philly until 1934.
Some people do still listen for distant stations - try these links:
National Radio Club
International Radio Club of America
My AM DX blog
But you're right, the programming stinks. At sunset when I can't get the NPR station anymore, I only listen to AM at the top of the hour when someone might (or might not...) run the required station identification. Nothing else is worth listening to.
I did once receive two British stations here in the Nashville area, transmitted direct from the UK.
"clear channel" stations are not allowed to increase power at night. While I haven't specifically mined the FCC database, I can say with considerable confidence that there are fewer than ten AM stations in North America that run more power at night than during the day.
However, "clear channel" stations are not required to *reduce* power at night. Most other stations are, and/or are required to switch to a directional antenna that concentrates all their power in a specific direction.
Technically, "clear channel" refers to the frequency, not to any specific station. For example, 720KHz is a "clear channel", and in theory any station operating on that frequency could call itself a "clear channel" station. Many do.
"clear channel" stations are divided into three classes, A, B, and D. Only one Class A station can exist on a frequency, and that's the dominant station most people think of when they think of a "clear channel" station. This station is allowed to operate 50,000 watts non-directional day & night, and is not required to protect any other station from interference. All other stations on the frequency must protect the Class A station.
For example, on 720KHz, WGN in Chicago is the Class A station. KDWN in Las Vegas is one of several Class B stations on 720; KDWN runs 50,000 watts 24/7, but is required to switch to a directional antenna at night, limiting the amount of power radiated in the direction of Chicago to maybe two or three dozen watts. (I think you can reasonably assume the KDWN transmitter is northeast of Las Vegas!).
Class D stations are those that are not allowed to operate at all at night, or are limited to nighttime powers less than that required for a new station. (generally, less than 250 watts; sometimes as little as one watt. No new Class D stations are being authorized.) An example of a Class D station on 720 is WGCR in western North Carolina, which goes off the air completely at sundown to protect WGN from interference.
Microwaves are a subset of radio waves - there's nothing wrong with calling it "satellite radio".
The common usage of "Internet Radio" is the one that isn't technically correct, in most cases. (unless your 'Net connection is WiFi...)
How to listen:
You'll hear a lot of static, but every once in awhile, you'll hear a brief burst of signal. This is (probably) a distant station's signal bouncing off the ionized trail left by a meteor. Short bursts can be just a "ping"; long ones have lasted as long as a minute! (1-5 seconds is most common) Stations can be between 500 and 2000km distant. If you're really lucky you might even hear some identifying information, like a local commercial.
This also works with analog TV, primarily on Band I (in the Americas: "low-band VHF" channels 2-6). It's unlikely a burst will be long or stable enough to allow digital reception. And, of course, you have to have an antenna on your TV - the only way the meteor shower is going to affect your cable or satellite reception is if a meteor hits the satellite!
More useful links:
http://www.qsl.net/dk3xt/ms.htm
http://www.imo.net/radio
http://www.veron.nl/amrad/mslinks.htm
It certainly wouldn't be the first time the current FCC has ignored the facts to implement what lobbyists were telling them to do. Admittedly, sometimes Congress gets into the act too. Looking at strictly technical issues, we've seen:
IBOC digital radio, where a spurious-emission limit intended to cover intermittent splatter like cymbal crashes and the crack of a baseball bat is used to justify digital sideband hash that's there 100% of the time. (and causes severe interference to existing analog service)
Low-power FM, where you can't have a station on 90.5 in West Memphis if it originates its own programs, because it might interfere with existing stations on 89.9 and 91.1. But if the station instead relays a St. Louis station, not only does it not interfere anymore (?!) but it can run 2.5 times the power & operate even closer in frequency to the 89.9 and 91.1 stations.
Broadband over power lines, which like IBOC uses interference exemptions intended to cover brief, intermittent, and unintentional transmissions to justify signals that are present 100% of the time and cause severe interference to existing stations. (it's also touted as a way of getting broadband to unserved rural homes - but to date has been deployed only in well-to-do urban suburbs...)
When I had my first experiences with the Commission - getting a ham radio license back in 1973 at age 14 - the FCC was a respected organization. Everyone expected their technical rules to be based on real science. It sure isn't that way anymore!
It would be interesting to see a link on this "phased array tech". Phased arrays have been around for a long time - the first one used in broadcasting was installed in Florida back in 1932. They do allow multiple transmitters to share a frequency, but there are limits.
You still can't have two stations covering the same place on the same frequency. To use a phased array to make two stations possible on the same frequency, each station has to sacrifice some of its coverage area.
The technology has made thousands of additional AM stations and a handful of additional FM and TV outlets possible. It doesn't come anywhere near creating unlimited spectrum though.
I have a HD radio, and it definitely doesn't sound *worse* than analog. Except for one station that has it set up wrong.
Can't say that it sounds any *better* either. By the time a station (either AM or FM) is strong enough for the digital to work, it's strong enough to deliver a nice clean analog signal. The FM stations, I simply cannot tell the difference. The one AM station, if I listen real close i can hear artifacts but you have to listen for them to find them - most listeners would never notice.
on the other hand... all the XM/ Sirius formats work everywhere. If you like classic country, to get it over WSM-HD you'd better live in the Nashville metro area. Get more than 120km from Music Row, and it'll be gone. The classic country channels on Sirius/XM work everywhere in North America.
120km is probably rather optimistic. With my $300 HD radio, I have to have a 80m outdoor antenna to get the HD signal of a 50kw station 30km away. That'd improve once we drop hybrid mode for all-digital & increase the digital power -- but I don't expect to live long enough to see that happen. Too many analog radios out there.
Right now, AM (MW) stations are not allowed to run HD at night. The HD signal is carried in the two adjacent channels. (for a station on 1510KHz, the HD signals are carried in 1495-1505 and 1515-1525KHz) This results in severe interference to, in this case, 1490, 1500, 1520, and 1530. The first-adjacents (1500 & 1520) are not assigned for use within the coverage area of a 1510 station. 1490, on the other hand, is a problem. I've heard interference from a 1510 HD station within the city officially served by a 1490 station, about 60km from the 1510 transmitter -- and less than 6km from the 1490 transmitter. (I may have heard the interference in places where I could see the 1490 transmitting antenna!)
If HD AM is allowed at night, definitely distant reception will end; if you don't live in a large city you may lose most of your nighttime AM service. (at my home ~50km from Nashville, WSM is probably the only AM station I'll get at night in a fully-deployed HD world) That aside, it looks like a lot of local service will also be impacted.
The story isn't quite as bad on FM. The HD signals are carried only in the first adjacent channels. (95.3 & 95.7 for a HD station on 95.5) In some cases this will still be a problem, especially in deep-suburban areas or on cheap radios.
I am not particularly impressed by the HD coverage either. I have to search for a "sweet spot" to get the HD of an 80kw station 50km away with an indoor antenna. That's not necessary with analog. (worth doing, for the excellent digital-only programs on WPLN-HD2) Again the coverage will probably improve in all-digital mode, if we ever get there...
This system was designed first & foremost to protect local stations from competition, It's got a long way to go before it provides reliable replacement service for analog.
Doug S.
(TV engineer & follower of radio tech trends)
Strangely enough this is not the first application of Morse Code in the tech world... Older UPSs have used Morse to signal error conditions.
They sent considerably more slowly than the folks on TV, and a sticker on top of the UPS showed what each code pattern meant.
It really made a fair amount of sense in context. Morse is a code that's extremely easy to generate by computer (even on a PIC with limited power), and can be read by ear by a skilled operator. For slow speeds and the limited vocabulary of a UPS, it wouldn't take much skill to read the Morse well enough to know what's going on. And the hardware costs of doing this in a UPS (or similar device) are zero, if you're going to have an audible error annunciator anyway...
Anyway, I think the idea of using Morse to send text messages is an excellent one. It's a whole lot easier to manipulate a single button in an timed manner than it is to find the right key on a 12-button pad and *then* manipulate it in a timed manner...
I believe anyone who can learn to type can learn to send Morse at at least half their typing speed. That's a whole lot faster than most of us can text!