Portable Radios

Posted by: Anonymous

Portable Radios - 06/01/06 07:15 PM

I was wondering what some good portable radios out there are. I just got myself an Eton Grundig S350, nice radio.

I was also looking at Eton’s emergency radios, and got to thinking was there a radio out there with AM/FM/SW and UHF TV 2-13 all in one. With the Eton emergency radios, you get either TV and NOAA or SW, both nice by themselves. However, is there something with both, but still small (not as big as the S350 I got)? Different manufacture is fine. This is not necessarily for emergency use, but for all the traveling I do on the weekends.

In addition, where would I look for a regular AM/FM radios with great long range receive?
Posted by: fugitive

Re: Portable Radios - 06/02/06 05:04 AM

IMHO, SW radios are over rated for survival purposes. Most of the domestic broadcasts are evangelistic or conspiracy shows. The conspiracy stuff can be entertaining, but doesn't help you stay alive. They do not have any local coverage either. Most of the over-seas stuff is boring beyond description and primarily thinly veiled propaganda. The US govt sponsored SW broadcasts also fall into this category.

The BBC arguably has some of the best world wide news coverage, but their transmissions to the US have been cancelled. It is still possible to pick up some of their broadcasts from the eastern US, but quite difficult now from the NW US. Great info, but not so useful in a crisis.

There may be some limited benefit to receiving ham radio broadcasts, but this is going to be exclusively SSB broadcasts, requiring a more sophisticated SW receiver. Even then, the ham broadcasts are often logistical in nature and may be of little benefit to you. Locally after the last earthquake I found the local ham communications were of little benefit. On the 2m band there were lots of folks sharing their personal observations and experiences. It was interesting, but of limited survival value. The 2m and 440 MHz communications are available on a simple UHF/VHF scanner.

On the other hand, after the Northridge earthquake in So Cal, it was determined that the TV stations had better and timelier information than the government run Emergency Operations Center. TV stations with their helicopters and news gathering staffs have honed the craft of local information gathering on a daily basis.

An AM/FM/TV radio would be ideal to help sort out a local disaster or emergency. Weather band would be a nice bonus.

I also find a UHF/VHF scanner (police/fire etc) to be indispensable. If you take the time to program it correctly, you can get info on specific concerns before it is available to the TV news folks. It is especially nice if you live in an area that uses trunked communications. All communications for a specific incident use the same "Talk Group". All communications go through a repeater. This allows you to monitor an incident without changing frequencies and allows you to hear even the low power handi-talkies. I have monitored local emergencies that were being covered by the TV stations, but with 10 times the details, and in real time.

Shortwave is a hobby.

AM/TV/Weather radios and UHF/VHF scanners are survival tools. Shortwave is a hobby.


Good luck, TR
Posted by: harrkev

Re: Portable Radios - 06/02/06 02:17 PM

I would look at a Yaesu VR-120D. This is a "DC to daylight" receiver. http://www.yaesu.com/indexVS.cfm?cmd=Dis...mp;isArchived=0

You could also choose a similar Icom IC-R5. http://www.icomamerica.com/products/receivers/r5/

You could also get an Alinco DJ-X3, but I would prefer the Icom or Yaesu.

Both the IC-R5 and VR-120D have bar antennas for broadcast AM reception. I do not know about the Alinco.

All three of these are under $200 - which is still a bit expensive. I must admit to be impressed that they can make such a versatile radio that is smaller than a pack of cigarettes.

Here is one store that I trust. http://www.gigaparts.com/matrix.php?catcode=z-rx Scroll down to the "handheld" section.

Note that the antenna makes a BIG difference. None of the included antennas will be that good for shorwave. Your best bet is to get a SMA or BNC plug (depends on which model you get) and attach ten feet of wire to the center conductor. This setup should also be OK for CB radio too. The included duckie should be OK for TV reception all the way up to police bands (including weather, marine, FRS/GMRS, FM radio, and aircraft).
Posted by: Arney

Re: Portable Radios - 07/06/06 10:02 PM

The Yaesu VR-120D and Icom IC-R5 look like very good DC-to-daylight receivers, but can someone explain what makes these two products "receivers" while products like Uniden Bearcats are "scanners"? Besides scanning speed and possibly frequency range, depending on the model, I'm wondering where the difference lies? Or is it an artificial distinction?
Posted by: paulr

Re: Portable Radios - 07/09/06 10:56 AM

I agree about shortwave. Don't forget, too, that TV band radios will stop working in a couple years, when the shut down analog TV.
Posted by: harrkev

Re: Portable Radios - 07/10/06 01:29 PM

Quote:
The Yaesu VR-120D and Icom IC-R5 look like very good DC-to-daylight receivers, but can someone explain what makes these two products "receivers" while products like Uniden Bearcats are "scanners"?

There are some differences. Scanners are designed for the purpose of scanning large numbers of frequencies, usually public service and aircraft. Therefore, scanning speed will be pretty high. Also, scanners usually omit certain frequency ranges. Nobody is going to scan broadcast stations, so scanners usually omit all broadcast frequencies. Scanners (almost) never receive anything below 30MHz. Usual is three bands: around 30-50MHz, around 110-180MHz, and around 400-500MHz, and some may offer around 800MHz to 900MHz. This leaves out: shortwave, CB, AM broadcast, FM broadcast, TV audio. Some of the more expensive scanners can also receive digital and trunked police bands.

A DC-to-Daylight strives to receive as much of the spectrum as possible, including AM/FM/TV/shortwave. Scanning speed may not be quite as fast, and forget about monitoring any digital transmissions. But I would much rather have one of these.
Posted by: Arney

Re: Portable Radios - 07/10/06 02:36 PM

Thanks, Harrkev. Useful response. Although similar in many ways, they're different tools for different jobs.
Posted by: Fitzoid

Re: Portable Radios - 07/11/06 06:11 AM

Oh my, I haven't posted here in a while since I was busy finishing grad school (yay!), but this thread caught my attention.

I think some of the info in this thread is slightly misleading, so I wanted to throw in my $.02.

In my humble opinion, for the typical person a small, inexpensive battery operated AM/FM radio is more than sufficient for emergency needs. NOAA reception is a fine bonus, but you can certainly manage without it. Most modern radios get well over 100 hours of continuous play on a single set of batteries. (Just for example, my C.Crane CCRadio gets 250 hours on one set.)

I tihnk the rechargeable crank radios are largely a gimmick, as *all* current rechargeable battery technologies have very finite life spans. (In other words, the rechargeable batteries entirely die after some period of time and become useless.) I collect radios, so I do have a Freeplay Plus, among others with built-in generators, but I'm not particularly impressed by any of them. I definitely prefer disposable lithium batteries (10 year shelf life) or alkalines as a power source for emergency use. (CostCo sells alkaline AA's in 24 packs for $10.)

Also, just for information's sake, your car's radio is probably the best one you own, unless you are seriously into radios. This has to do with it having a better antenna, a better ground plane, its being outdoors, and the fact that car manufacturers tend to put excellent radios into cars. Also, in case you aren't aware, AM signals can travel enormous distances at night (this phenomeon is called DX), which is why you should be sure that your emergency radio has AM reception. You can hear halfway across the country on AM at night, so you'll be able to get news even if all your local stations are down.

As for getting a fancier type of radio, I think they are total overkill for most people. The "DC to daylight" reference above is a HAM radio term for wideband radios that cover many legal frequencies bands (e.g., MW/HF/VHF/UHF). I just don't see the point for the average person to buy one of these expensive radios. This is all the more so since 9/11, when so many state and local governments have moved to trunked or digital systems which are inaccessible to general wideband receivers like the ones mentioned above. (The dubious wisdom of this move and the waste of tax-payer money it represents is perhaps best saved for some other thread of forum.)

As for getting the latest type of scanner, which can receive/decode the more modern transmission modes, they are fairly complex to learn to operatate, program, and keep up to date. I think most people's preparation time is better spent elsewere unless you enjoy this type of thing. I don't happen to think monitoring the police/EMS/fire bands is of critical importance in most emergencies. Your local AM news station is probably more informative. And unless you're willing to take the substantial time in advance to understand what you'll be hearing, how to interpret it, and how to use your radio, you won't benefit from a scanner. It is not something you can figure out at a moment's notice.

I'll add for background that I'm a ham, active in ARES and NTS (those are amateur radio groups), a long-time DX'er, never leave the house without either a Yaesu VX-7 or a VX-2, and almost always carry a Uniden 396T, which is the current king of the consumer-grade portable scanning world. I've also hand-built my own radios (not from a kit), so I'm not anti-radio by any stretch of the imagination. Nonetheless, I don't think most people need to bother with anything beyond AM/FM for information gathering purposes. (For the most part, forget about shortwave these days -- it's for entertainment, not news.) Also, if you happen to have XM or Sirius, you can get CNN (and other networks') audio feeds which is great too, although my portable XM unit eats through batteries like they're going out of style.

Finally, I'll add that I *do* think everyone should get a ham radio license to communicate with family and friends in the event of an emergency, but that's a topic for some other thread.

Glad to be back!
Fitz
Posted by: Leigh_Ratcliffe

Re: Portable Radios - 07/11/06 07:47 AM

Best emergency radio is any small AM/FM/MW/SW radio that can pick up the B.B.C. world service. Local or CONUS stations may be hors de combat or subject to censorship. Depending on the nature of the emergency.
Posted by: Nomad

Re: Portable Radios - 07/11/06 12:41 PM

I have “credentials” similar to Fitziod. Long time ham etc. However I add the experience of having been in New Orleans during Katrina and Miami right after Wilma as a Red Cross Disaster Communications operator. I second Fitziods recommendation of a simple AM/FM radio. Something that anyone can operate and has simple electronic circuits.

Believe me, trying to remember how to run a complex radio when stressed, is very frustrating. The simple electronics means much longer battery life. Get one that runs on AA batteries if possible.

You may not be the one using the radio. Even with a simple radio, include a small “cheat sheet” describing its operation for those who may be “techno-challenged”.

In New Orleans, the local Public Broadcasting System stopped their normal programming and did a combined program using many of the local radio “personalities” who knew the local area and its unique circumstances. It was a very effective communications method and everyone listened to it. The information was accurate and they had a lot of “call in” type conversations providing up to date information.

I did not listen to local radio in Miami so can not speak to that. However I did spend a lot of time in areas with no power and it seemed that everyone had a radio on the local stations. Wilma did not affect such a wide area like Katrina so there were many functioning radio stations outside the affected area that were providing programming to devastated areas.

Also these radios are cheap. There are many very good ones available for under $25.00. Get some lithium batteries and it will be ready to go for the next 10 years.

Also, interested folks should investigate getting a ham radio license. There were many repeaters (systems that greatly extend the range of walkie-talkies) operational within a few hours of Katrina. These were of great benefit to those wanting to keep in touch with other hams and as a local communications and information transfer system. For the first week, most of the public service (fire, rescue, police etc.) was transmitted over amateur radio.

It sounds odd, but the ham stuff was repaired so quickly because there are lots of hams and very few commercial repair folks. The local commercial repair people were working very hard, but they had to also take care of their families and still try to repair very complex systems with limited time, energy and parts. The ham equipment is much simpler, usually there is a large accumulated source of parts in the individual hams “junk boxes” and each repeater had a crew of hams working together to get the systems operational. I was very impressed with the actions of the ham community during Katrina.

For those trying to understand the somewhat complex world of radio, I have put together a bit which may help at my blog. Take a peek...look under the section about Understand Radio. I would appreciate comments (PM me directly please).

Nomad.
Posted by: harrkev

Re: Portable Radios - 07/11/06 04:40 PM

Fitzoid. Thanks for the thoughts. But I disagree on a couple of points.

First, you are right that an AM/FM radio is all that you really need. But "need" and "want" are two different things. In the event of an extended power outage, having the option of listening to something else besides AM and FM might be nice from an entertainment point of view. Shortwave would fill this gap nicely, and can be found for well under $50. Secondly, the ability to listen to the local 2M repeaters and TV audio would be useful as well for getting information. Hams are among the best informed people in the event of an emergency. The "DC-to-Daylight" would work well for this.

Secondly, I do recommend a hand-crank radio. I have the Grundig/Eton FR200 shortwave crank radio. You are wrong about the batteries. Lithium-ion batteries definately have a half-life even while in storage. NiCad batteries, on the other hand, can be stored for years with no ill effects other than self-discharge. I believe that NiMH batteries also survive storage well. The FR200 also has a single white LED built-in, so in one box you can have AM/FM/Shortwave, and illumination. Plus, you can crank it or put in AA batteries (your choice). Clearly, this is a lot of flexibility. The crank means not having to panic if the batteries in it are dead. You can use it all that you want, because you are not worried about "rationing" the battery power. The only problem with the FR200 is that it is too large for bugging out, but it is perfect for bugging in.
Posted by: teacher

Re: Portable Radios - 07/11/06 06:49 PM

fitz,

Good points and well reasoned. I'd second having a small am/fm radio handy.

TRO
Posted by: Russ

Re: Portable Radios - 07/11/06 07:48 PM

Are the rechargable batteries in the Eton/Grundig radios replaceable AA's that can be swapped easily or is it a different type battery?

I looked at the Eton/Grundig radios and then bought a Sony AM-FM TV Weather Radio instead. I can use standard NiMH rechargables (I already have a solar battery charger which will do four NiMH AA's) and not be hassled with cranking.

From what I can determine, the NOAA Weather channels are useless unless you are in their relatively small footprint. They use LOS ~162 MHz at 90-100 Watts, really just designed for guys out on their boats who need to know about storm fronts. However, it receives AM well, FM in mono format and the TV audio is very clear. I figure if a big earthquake hits it will be a race to see who can get their back-up power first and between AM, FM and TV audio, I should be well covered for local News.
Posted by: Equipped4Chicago

Re: Portable Radios - 07/11/06 08:34 PM

So from your vast experience, is there a radio you can recommend? A 7 day camping trip. Thats what I would need one for.
Posted by: Russ

Re: Portable Radios - 07/11/06 09:21 PM

I went with the Sony AM-FM TV Weather Radio . Runs on four AA batteries or 120 VAC and is a fairly simple reliable design.
Posted by: Fitzoid

Re: Portable Radios - 07/11/06 10:09 PM

Okay, from my "vast experience," <img src="/images/graemlins/tongue.gif" alt="" /> I'll recommend you consider a Sony ICF-S10MK2.

It's $10, Sony generally makes outstanding radios, and it compares favorably for distant AM reception with a $600+ ICOM R75. (See a review here.) You only need to worry about AM reception if you're in the wilderness; don't expect any FM reception unless you're fairly high up or near a major city. The radio weighs 7oz which is pretty good for backpacking, although some people might search for something lighter.

Also, if you're a ham, you should follow the Wilderness Protocol and monitor 146.52MHz on the 2M band. For the first 5 minutes of every 3 hour period starting at 7AM, many hams monitor this frequency for emergency communications. (It generally requires an LTZ -- a long tone zero via DTMF -- to get people's attention.) Some park rangers and police stations monitor this frequency constantly as well. You may want to ask at the ranger station if they monitor frequencies and if so, which ones. (Each VHF/UHF ham band has its own emergency frequency.) It's always nice to have a way to contact the outside world when your're out of cell phone range. (By the way, I should mention that you'd need a ham radio to do this, the above Sony is just a simple AM/FM receiver.)

Have fun and don't forget extra batteries,
Fitz
Posted by: Fitzoid

Re: Portable Radios - 07/12/06 07:35 AM

Hi Harrkev,

I enjoy your posts but I think you might want to be a bit more careful before telling someone "you are wrong." <img src="/images/graemlins/cool.gif" alt="" /> I know a little about battery chemistry and I'm afraid you seem to be somewhat misinformed on a couple of issues.

First, none of the the wideband radios you reference is likely to get much, if any, shortwave reception. Rubber ducky antennas are simply the wrong lengh for HF and they are generally tuned between 140 to 800 MHz rather than shortwave frequencies. (They also tend to have negative gain.) A dedicated shortwave radio (or a just a long wire) might be an alternative, but shortwave quality in the US has certainly gone downhill in recent years. (How I miss Alistair Cooke on the BBC.) And it's just a wild guess, but I don't think most Americans would find Deutsche Welle's English language service particuarly entertaining.

As for batteries, I strongly (but cordially) disagree with you. NiMH battteries need to be carefully stored and conditioned (i.e., fully charged, discharged, and recharged, etc.) and you're not going to get that with a crank that charges them up to 10% of their capacity. They require this conditioning both when they are new and when they are taken out of storage. My guess is that the built-in NiMH's in your Eton are not in the best of shape. Even worse are the radios (like the Freeplay) that have solar chargers that constantly trickle charge the batteries. That is among the fastest way to kill most rechargable batteries, although a notable exception are sealed lead acid batteries which manage it quite well. (That's why hams love them for emergency use.)

Finally, you seem to have lost track of what I was referring to -- lithium-ion batteries are rechargeables --not disposables -- and they are not at all what I'm talking about. There are many, many types of lithium based batteries and lithium iron disulfides are the typical AA sized disposables you'd buy at a store. They have an extremely low self-discharge rate and the latest estimates for the most recent chemistries have raised their shelf-life to an astonishing 15 years. As far as I know, nothing else commercially avaiable comes close to this. They are also very light weight, which makes them great for EDC, and they work in extreme temperature ranges, particularly in the cold, which leaves alkalines in the dust.

Anyway, I don't mean to bust your chops, but I think most people have limited budgets for survival equipment and it's easy to get carried away with exotic solutions to simple problems. However, in this case, there are very low cost solutions to this problem, and I think they're worth advocating. As for listening to hams as a source of information, I remain somwhat dubious, but perhaps you have a point. Nonetheless, I'm not sure the benefit is worth the cost or the trouble of doing so for someone who isn't active on the ham bands on a regular basis.

Best,
Fitz
Posted by: harrkev

Re: Portable Radios - 07/12/06 02:01 PM

Fitzoid...

Sorry. Didn't mean to ruffle your feathers...

If you check my earlier posts, I specifically recommended a long wire for shortwave. Duckies are not great for anything HF. BTW: I EDC a Kenwood TH-F6a. This is a DC-to-Daylight rig with 5W transmit on 2M 220MHz, and 440MHz thrown in for good measure. Fun little toy.

Second, do not be so certain about the batteries. Those crank radios may sit on a box on the store shelf for a year or two. My radio actually takes a cordless phone battery. I know that cordless phone batteries sit on a shelf for years at Radio Shack. You are right about wearing them out from use, but I imagine that most people are not going to hand-crank a radio on a daily basis. The crank is there for an emergency. And if the rechargable battery wears out after two months of daily use, well, if your emergency lasts two months then a radio is the least of your problems.

I do agree about lithium primary cells being a nice idea. Unfortunately, cost is a big issue. Lithium AA batteries are terribly expensive. The last time that I purchased AA batteries, I got a brick of 100 for $17. That much money would only buy a handfull of lithiums. Unless you REALLY need it, lithiums are too expensive. In your past post, you also posted a link to an inexpensive Sony radio. Some people would be apprehensive about buying a $10 pack of batteries to go with their $10 radio. 123 cells are a better buy if you order over the internet, but I have never seen any radio that runs on those.

As I mentioned before, another thing that I like about the FR200 is that it has a built-in white LED useful for general illumination. I went through a couple of hurricanes two years ago, and spent many days without electricity. Having a light is comforting when it is pitch back out. Of course I have a lot of flashlights, but having one light that I know will not exhaust my battery supply is even more comforting. With battery-powered lights, I go into rationing mode, and try not to use a light if I don't really need it. With the FR200, I could just turn it on and then crank for 30 seconds every 15 minutes. All in all, a nice addition for the house.

I do, however, agree with you on the cost issue. Getting a $10 radio for now is perfectly fine if you have a few extra AA batteries stored away, and have to discipline not to rob the battery supply to refresh the kids toys and remote controls. But the FR200 makes a nice upgrade later on down the line.
Posted by: Tjin

Re: Portable Radios - 07/12/06 02:08 PM

i'm not sure with the many models of handcranked radio's out there, but mine two will accept alkalines. So even if your rechargable battery dies, you still have the battery option. On normal radio's you only have one option.
Posted by: Eugene

Re: Portable Radios - 07/12/06 03:25 PM

Cordless phone batteries can be stored for a long time because they are NiCad which can be stored in a somewhat discharged state and have the least self discharge out of all the rechargables.

Fitzoid, you wrote that NiMH must be carefully conditioned (fully discahrged and recharged), I'm assuming that was just a type and you meant NiCad becauee NiMH you don't want to fully discharge and recharge if you can help it, NiCad are the only batteries which should be conditioned this way. NiMH, LiON and such you should recharge when you use them and not let them get too low so as to not use up all the charge cycles or risk cell polarity reversal.

Even NiCad don't have a shelf life of forever, if you were going to buy one of these radios then at least pull it out and recharge it on a regular basis depending on the cell technology. I wonder if any are using a big (think 1F) capacitor, a tiny headphone radio could run a while from one of those.
I don't care for the idea of a hand cranked radio either, maybe because most of them just seem so cheaply made but it seems it would be much simpler to have the charger seperate from the radio and use a standard battery.
Posted by: Eugene

Re: Portable Radios - 07/12/06 03:30 PM

I've found that if your in range of a NOAA weather broadcast then your probably in range of whatever they are alerting on.
Posted by: Eugene

Re: Portable Radios - 07/12/06 03:31 PM

I don't understand the reason for shortwave. If a disaster if big enough to make the BBC news then you have a lot more to worry about, world news services generally don't cover the local fires/floods/tornaods.
Posted by: Fitzoid

Re: Portable Radios - 07/12/06 04:19 PM

Harrkev, no worries -- no ruffled feathers on this end! <img src="/images/graemlins/cool.gif" alt="" />

I think we may have somewhat different attitudes towards emergency gear. I almost never put anything away on a shelf for "emergency use only," except maybe MREs and lithium batteries, simply because they're too expensive to play with all that often. I try to use anything I might rely on in an emergency both to make sure it works and to make sure I know how to work it. I suppose I must be of a suspicious bend (and I like to play with my toys), because I don't trust anything to work until I've tested it. In the process, I've seen random things from knife blades snap to batteries explode to bags fall apart, and I'm glad to have some sense of what I can rely on.

So, once you've started using those crank radios, they are generally on their way downhill, which is why I think paying for their half-assed (am I allowed to say that here? <img src="/images/graemlins/smile.gif" alt="" />) recharging mechanisms is silly. Although for short-term, single use applications, e.g., distributing them to hurricane or other disaster victims, they may well be the best solution available, so your point is well-taken.

However, I personally plan for longer term and repeated use for my equipment. As I mentioned earlier, I do have a couple of crank operated radios, but they're not what I'd grab if I was running out the door. My primary BOB has a cheap, tiny Sony AM/FM/SW that runs forever on AAs and a 20 foot wire antenna.

I have a separate BOB for radio equipment, including a 12AH SLA battery, with solar/AC/DC recharger. My higher-end ham radios all have wideband coverage for TV, NOAA, etc. and I have a disturbingly large assortment of antennas in there too. Maybe sometime I'll add an FR300 and just save it for actual emergencies, but I'm not sure I could resist the temptation to play with it. (My wife has patiently accepted my radio interests with surprisingly good humor.)

Anyway, I've got a feeling we agree on more than we disagree. By the way, the built-in ferrite bar in your TH-F6a is a great addition. I wish they came on Yaesu HTs.

Fitz
Posted by: Arney

Re: Portable Radios - 07/12/06 05:17 PM

Quote:
...once you've started using those crank radios, they are generally on their way downhill...


For the recent models that only have a (usually not user-replaceable) rechargeable battery and get used frequently, I would generally agree with this statement. I have a Coleman Ranger that I listen to daily in the morning. It's a solidly built AM/FM radio, unlike many other hand-cranks out there, but I have noticed that its rechargeable battery lasts for fewer days now than when new. Short of disassembling it, there's no provision for replacing it. Bummer. For radios like the FR series, which can also accept regular batteries, that is a plus. But if you're forced to use regular batteries because the rechargeable has gone bad, then that negates the reason for having a hand-crank in the first place.

In contrast, I also have a spring-driven Freeplay Plus-type radio with solar panel that has served me well for many years. Despite a lot of use, I haven't noticed the spring wearing out. I take comfort in knowing that there is no battery to wear out or to worry about when in long-term storage. So, with this radio, whether I use it often or just leave it in the closet, I feel like I can count on it. Too bad spring-driven radios are all but extinct these days.
Posted by: Leigh_Ratcliffe

Re: Portable Radios - 07/12/06 06:28 PM

Tornado's, Earthquake's etc will make the BBC. Besides, the more bands you can cover, the better.
Posted by: Fitzoid

Re: Portable Radios - 07/12/06 10:24 PM

Quote:
In addition, where would I look for a regular AM/FM radios with great long range receive?


It just occurred to me that I don't think anyone has addressed the last part of your question yet.

AM and FM travel by very different paths. By and large, FM signals are line-of-site and don't travel very far. (There are exceptions, but 50 miles is roughly the maximum distance they can travel because of the Earth's curvature. High frequency FM signals (in the VHF spectrum) pass straight through the Earth's atmosphere and into outer space. (You could pick them up on the moon with a really good receiver.)

AM signals (which are generally on much lower frequencies) bounce off the Earth's ionosphere (even taking multiple hops), which is why they can literally travel thousands of miles. This is why at night I reguarly hear Chicago radio stations, e.g., WBBM, in Boston, and why WBZ -- a Boston station on what is called a "clear channel" -- is heard in 38 states. By the way, listening to distant stations is called "DX'ing." The time of year, the time of day, and sun spot activity all affect this, so the actually story is more complicated. Regardless,low frequency AM (and similiarly shortwave) signals tend to travel a long ways.

Also, to be clear, AM and FM aren't frequency distinctions but rather how the signal is encoded. Standards have emerged, however, and you'd have to look hard to find someone transmitting an AM signal at 50 MHz, although some people (particularly old hams) still do.

All that being said, the main concerns with an FM radio are things like adjacent frequency rejection, attentuation, audio and antenna quality. You can get quite exotic and start talking about multipath rejection, filter widths, notch filtering, adjustable intermediary frequency, DSP processing, etc., which are mostly irrelevant for broadcast FM radio. The most important thing for good FM reception may simply be having a good FM antenna.

For the AM side, the main thing you might want is synchronous detection, which is the ability to choose between upper and lower sidebands, one of which may be distorted by an adjacent frequency.

Getting more practical. I think the best performing radio on the current market for AM DX'ing is the CCRadio Plus . It is simply an excellent AM/FM/TV/NOAA peformer, but offers no fancy options other than tuning. It also has an excellent audio quality. (It's so good that my wife has taken mine and won't give it back.) As I mentioned somewhere else in this thread, it gets 250 hours on a set of batteries which is pretty extraordinary. It is a great at home for general and emergency use but it is pricey. (It's also too big and heavy to carry around.)

The best performing radios of yesteryear, which you can still find on ebay, were the Sony 2010 and the GE SuperRadio II. (Note I said the SuperRadio II and not the model III.) These are my favorite AM DXers, and I replaced the filters in my Sony with custom Kiwa filters (anyone remember those?) which improved audio quality remarkably. My Sony 2010 is still my favorite receiver of all time and still sees regular use.

You can also buy any number of external antennas for AM radios which can improve distant reception remarkably. The simple Select A-ntenna is just an inductively coupled massive ferrite loop antenna that you just place next to your radio. There is no physical connection. It looks weird but works great and requires no external power.

Also, remember the ferrite bar antennas hidden inside most AM radios are directional. You should rotate the radio as you scan the band and you will hear different stations in different directions. This is part of the fun of AM DX'ing.

Hope this helps!
Fitz
Posted by: Eugene

Re: Portable Radios - 07/13/06 01:02 AM

I should have been more specific, but yes they will make it on the BBC but it will be mostly " a Hurricane hit New Orleans in the USA killing hundreds" but nothing specific enough to be of use to those in the situation. I agree with the other poster who said Sw is a hobby, it would give you something to pass the time if your stuck in the shelter but thats about it. I wouldn't pass a radio that had it for that reason but I wouldn't want SW over NOAA or something else.
My first SW, I wasn't even in high school yet, built on a cardboard box along with various am radios from crystal to a few transistors.
Posted by: Eugene

Re: Portable Radios - 07/13/06 01:06 AM

I think a hand cranked/operated charger on its own could have use for recharging your known good batteries, just keep is seperate from the radio so failure of one part doesn't render the other useless.
What kind of solar charger are you using for the SLA? I've been looking at setting up something like that.
Posted by: Fitzoid

Re: Portable Radios - 07/13/06 01:06 AM

I totally agree. Disaster survivors want to know mundane details like when fresh water and food are coming, when evacuation buses might be arriving, and where to go for urgent medical treatment. You're not going to hear that on the BBC.

Posted by: Eugene

Re: Portable Radios - 07/13/06 01:56 AM

And don't get me wrong, I'm not saying something like "don't ever buy shortwave" I'm saying it should be low on the priority list.
Now a days even the AM stations may not be online as they are the low budget. The top 40 pop FM radio stations with their million dollar advertising contracts have the $ to have the nice backup generators in order to get and keep those contracts so my bet is those and some of the TV stations will be back running when something happens. Our local, user supported Christian programming station gets knocked off the air for a bit every time there is a rainstorm, its all about the $ now.
Posted by: harrkev

Re: Portable Radios - 07/13/06 01:11 PM

Quote:
By the way, the built-in ferrite bar in your TH-F6a is a great addition. I wish they came on Yaesu HTs.

That is pretty hard when the guts of the Yaesu are encased in metal (magnesium). Yeah, the bar antenna is nice. But the VX-7 is waterproof and would likely survive things that would kill my TH-F6a. Both have their advantages. Now, if Kenwood would make a unit that was waterproof and also has 6M transmit like the VX-7, then they would definately have a Yaesu killer.
Posted by: Fitzoid

Re: Portable Radios - 07/13/06 01:24 PM

I was really thinking of my VX-2, which is pretty much deaf on MW and has an old fashioned plastic case.

Yeah, the VX-7 is the ultimate outdoor radio, encased in a magnesium Faraday cage. It is pretty much indestructible, totally submersible, and has proven itself over and over again. I love it. <img src="/images/graemlins/grin.gif" alt="" />