I’m asking this because I have to buy a new radio…my Grandpa’s 1935 Crosley doesn’t work anymore…so I have to break down and buy a newer one! (I’d like to keep the old Crosley going…but I can’t get tubes for it anymore).
Anyway, I read a whle back that DIGITAL RADIO has now been fully tested, and the FCC has approved the format. So, will that make all existing radios obsolete? Or, is the radio thing like HDTV…great promise but nobody really wants it?
Hell, I’d like to keep the old stuff running…my 1963 WESTINGHOUSE TV works just fine!
I doubt if AM radio will ever be totally obsolete. It’s simple and robust. In a pinch, an AM radio receiver can be built from a low-forward-voltage diode, some wire and a high-impedance earphone. Aircraft use AM, as does the audio portion of an analog TV channel. All else being equal, an AM signal travels slightly farther than an FM signal. Digital is nice and clean, but the equipment is complex and difficult to repair.
This is more a IMNO, But AM has too much of an installed base, talk radio is almost exclusivly AM and many people listen it in their cars to - from work. If a station went digital then they would quicky lose a high percentage of listeners.
Also a total wag, but it would seem that a anloge signal would be received further then a digital signal broadcast from the same location. The analoge signal might have static but still usable, a incomplete digital signal just becomes broken up or inaudiable.
I’ve heard that GE makes a kick @$$ radio that excells at AM recpetion, IIRC its the superband or something like that. And it’s fairly cheap (under $50). CCrain makes (re-labels) it too, but it cost more from them. Grundig makes some excellent AM radios w/ digital tuning, but the costs are about 3 to 6 times htat of the GE model.
I think you are confusing digital with FM here . At present most radio is broadcast in analogue both in AM and FM modes with the newer digital radio using a different format. How far a broadcast will reach is not down to the broadcast mode but to the frequency that is used. Long wave ( used in Europe ) can cover most of the continent with one transmitter . Medium wave ( your AM in the US ) will cover a fair distance . Short wave ( because it uses the ionosphere ) can get round the globe . FM , which uses VHF frequencies ,is almost just line of sight . There are plans to have digital broadcasts on short wave which means world-wide coverage and much better broadcast quality.
In the US, the sound is FM modulated both for VHF and UHF. It seems that France, which uses SECAM instead of NTSC, is the onlly nation curently using AM for audio, and that only for the UHF band.
Info on the channel systems:
http://www.tvradioworld.com/directory/Television_Standards/page5.asp
Info on current countries usage:
http://www.tvradioworld.com/directory/Television_Standards/page6.asp
I forgot to add that we have had digital radio up and running here in the UK for a couple of years now. The only drawback is that the sets cost at least £100 but they are getting cheaper . One advantage of digital is that you can get many more radio stations on the spectrum because a group of stations will digitally time share on a singal frequency ( or multiplex ) . Depending on the sampleing rate you should get CD quality sound and some sets have a small screen on them to give information such as play lists and additional facts about the programme.
As to digital tuning on the Grundig rdaios , that is nothing to do with digital broadcast , just a fancy way of tuning an analogue radio.
I haven’t read your links, but my memory did just kick in, and I had that backwards: it’s the video portion of the signal that is AM, not the audio, as you correctly pointed out.
Incidentally, ralph124c, what tubes do you need for your radio? I bet I can locate a source for you, unless they are VERY unusual tubes.
This is one of the reasons I don’t think AM will ever be obsolete. The larger stations bounce off the ionosphere and travel very far at night - I can hear AM 750 our of Atlanta once the sun sets, over 400 miles away. The best FM, to my knowledge, reaches ~120 miles. Now XM radio might be worth looking into since it uses satellites.
Right now, I only have 2 stations I can stand on AM, one oldies and one all news and traffic.
I wish more music was on AM, because those stations always come in stronger and clearer. Sure there’s no stereo, but few FM stations are stereo anyway.
I think it’s hard to compare now, since AM radio uses a much lower frequency than FM radio.
Would AM reach further if you compare it with an FM transmitter with the same power and frequency?
The U.S. has a number of clear channel AM radio stations. These were important stations, usually located one to a city, that were given sole permission to broadcast at 50,000 watts at their frequency. For that reason you could hear them all over the country at night.
There’s no reason to do this in today’s world, but these stations still exist. During the blackout I used a walkman radio to get news. I could clearly hear stations like KMOX in St. Louis and 880 in NYC (whatever it is now - I think it used to be WCBS) in upstate New York.
AM signals will bounce off the ionosphere while FM go more or less straight and don’t bounce as well. (Somebody more technical will correct that, I’m sure.) You can almost always hear AM stations better and farther at night. FCC regulations also state that many stations must therefore lower their wattage at night so that they don’t interfere with other broadcasts.
When I was in high school a bunch of us used our newfangled transistor radios to try to capture as many stations as possible from all around the country. We could pick up literally hundreds, from as far away as California.
The larger bandwidth means that music sounds better on FM, but since talk doesn’t need much bandwidth, there will always be a place for talk on AM and a place for AM in order to hear talk.
Exapno Mapcase: Your and your highschool friends were taking part in a hobby called DXing (distant listening). There are DXing clubs all over North America. You can actually fill out formal detection reports and mail them to the requisite radio stations. The station will send back confirmation cards - the idea of the DXing hobby is to collect as many cards as possible.
As for AM radio - during the blackout, I had no battery powered radio. I actually built a simple non-powered crystal (diode) radio. I was able to pick up CFRB 1010 from Toronto, a clear channel station. This was the only way I could stay informed.
Yes, the notion of “surfing the web” goes back way before anyone even thought of computers.
Trolling for distant stations started with the very first handmade crystal sets and headphones, and was a popular hobby among radio “geeks” [anachronism warning] in the 1920s and even earlier.
Ham radio operators were the ones who truly perfected the hobby. I always associated DXing with hams, and I believe the radio hobbyists piggybacked on the hams rather than vice versa.
The difference for me and my friends is that we were able to do a lot of it late at night, after we were supposed to be in bed and asleep, because a transistor radio and ear plug needed no lights.
There are new “in-band” digital formats for both the FM and AM (mediumwave) bands. However, in both cases the idea is, at least for now, to transmit both the old and digital signals simultaneously, so analog receivers can still receive the old signals, and digital receivers the new ones. Then, at some not-yet-specified date, when most everyone has digital receivers, they can turn off the analog transmissions, and give the freed-up bandwidth to a better quality digital signal.
With its wider bandwidth, this seems plausible for the FM band, but there are still huge problems on the AM side. Currently the Federal Communications Commission will not allow AM stations to transmit digital signals after dark, because of the increased interference to distant stations. The FCC was never able to get together a critical mass for AM stereo in the 1980s, and I have great doubts whether the AM band will be converted to solely digital for the forseeable future.
Conventional wisdom is that AM radio persisted after the development of static-free FM because so many AM stations were already in operation and so much money had already been invested in it.
The financial stakes are even higher now. With large corporations having so much vested interest in AM, it seems likely that it will endure for a long, long while.
Personally, about the only thing attractive about AM is that I can sometimes pick up old time radio shows such as The Shadow and Suspense. Where I am located this is sometimes a tremendous hassle however. There are few things I find more annoying than listening to The Jack Benny Show and, halfway through the program, suddenly begin hearing a minister shouting about who “Europe hates God”. That happened just this past week.
[quote…were given sole permission to broadcast at 50,000 watts at their frequency. For that reason you could hear them all over the country at night.
… I could clearly hear …880 in NYC (whatever it is now - I think it used to be WCBS) in upstate New York[/quote]
770 WABC is a 50,000 watt station IN NYC, 810 is the 50, 000 watt station in Albany. If only one station per city can transmit at 50k, then it cound not be WCBS 880 out of NYC
Do a google search for ‘GE super radio faq’
I have a radio shack clone of this radio and it’s quite good at long distance reception.
AM radio died (past tense) for a very simple reason: no stereo. The signal quality is “good enough,” the range is great, works better while moving around in a car and is better at getting inside buildings with a moderate amount of metal. Since the FCC refused to institute a stereo standard, there’s a lot of nearly worthless AM licenses that used to be worth big $$$.
The “digital” ploy is a scheme to try and make those licenses worth some $ again. (They will be adding a digital subcarrier onto the AM signal.) It is probably too late.
(And I think people here underestimate the strength of AM signals. As a kid I listened to clear channel stations over 1500 miles away on a crystal radio. No battery, no transistors. But a standard AM radio of today is lucky to get stations 50 miles away. Thus killing the clear channel national ad market.)
True for the most part, although there is the phenomenon known as tropospheric ducting. I experienced it firsthand about a month ago, in the middle of the afternoon, when I was driving through what would have otherwise been a radio wasteland in west Texas. Instead of the occasional country or religious station, I picked up something at EVERY allocated FM frequency on the dial. I listened around a bit more, and heard W call signs for many of the stations, even though I was deep in K country. Finally, commercials … for businesses in Fort Meyers, Sarasota, West Palm Beach, and Naples. There was a duct between south Florida and west Texas!
I don’t know is this is a signal of AM’s decline, but it used to be that years ago, driving through the rural Midwest, if you scanned through the AM band, you would hear rock and country stations, farm broadcasts (“Uh-yup … soeme fascinating happenings today … wheat up a penny a bushel in Salina, down two cents in Hays, up a penny in Burlington, down a cent in Garden City”), local news, obituaries (!), and the usual assortment of commercials for State Farm insurance agents, farm implement and Chevrolet truck dealers, and Roundup.
Now, though, drive through rural Kansas or Nebraska, and the airwaves take on a different sound. One like “oompah oompah oompah oompah H’WAH! H’WAH! H’WAH! H’WAH! oompah oompah oompah oompah AY! AY! AY! EL GRITO! AY! AY! AY! oompah oompah oompah oompah AY! AY! AY! MI CORAZON! DIOS MIO! AY! AY! AY! oompah oompah oompah oompah AY! AY! AY! MI CERVEZA NO ES FRIA! AY! AY! AY!”
The farmcasts, mullet rockers and right-wing talkers have moved to FM, and the AM band is increasingly home to stations catering to the growing population of migrant laborers from northern Mexico. The stations sound almost exactly like the X-stations from Chihuahua and Sonora, complete with a reverb box that is never turned off, plenty of health-related PSAs, and DJs that talk so fast a native Spanish speaker might struggle to understand them.