extraordinary AM radio reception

[Rick Denney]

Here's what I would *like* to own *if* it exists:

A radio with extraordinary AM band reception including

- nighttime "directional" signals
- highly resistant to florescent lights/computer/vacuum/motors, and other electrical interference
- pulls in and locks in to "marginal" signals
- affordable (but doesn't have to be cheap)
- possibly refundable, if it doesn't live up to its brag
- 110 AC, DC/battery, or 12V DC auto current

If you can attach it to a computer, look into a Ten Tec RX-320 (which is a computer-controlled black box). And, yes, that's cheap by good general-coverage receiver standards. It also has short-wave reception, and everything else up to about 30 MHz. It runs on 12 volts and comes with a battery eliminator. And it's made in Tennessee (Ten Tec is in Sevierville).

But most of your issues are not a function of the radio, they are a function of the antenna. Hang a 50-100-foot dipole up outdoors and you'll avoid the interference from computer and flourescent lights to a certain degree.

Directional? Fuggedaboutit. A directional antenna for the AM broadcast band that would have any capture size would be, well, very large. Think hundreds of feet. Or a phased array of vertical antennas.

There are very few modern consumer-marketed AM radios of any quality, much less good ones.

What I don't know is whether it's attenuated in the AM broadcast band, but a call to Sevierville will answer that one.

http://radio.tentec.com/amateur/receivers/RX320D" target="_blank

Rick "who uses one as a second receiver for a ham station" Denney

[lgb&dtuba]

By it's nature AM radio will pick up all the atmospheric and impulse noises you don't want to hear. Eliminating those noises was one of the, if not the biggest, advantage to FM. So if you see claims for a particular radio stating that it doesn't pick or or eliminates those noises don't believe it.

You can reduce them somewhat with DSP, Digital Signal Processing, but you're going to be looking at fairly expensive shortwave radios, > $1000, before you get decent DSP. DSP was really developed for improved voice intelligibility, not music, so you will really reduce the hi-fi qualities of any radio utilizing DSP. I use an external DSP unit on my ham radio receiver and it does help me pick up and understand weak signal content, but I'd never use it for music content.

As far as picking up distant signals, I'd say the best way to accomplish that is with an old fashioned long wire outside antenna. So if picking up distant signals is your goal you'll get more bang for the buck investing in an antenna than a radio.

So, I'd recommend that any radio you consider should have provisions for both and AM and and FM external antenna. If you don't need shortwave coverage then something like this:

http://www.ccrane.com/radios/am-fm-radi ... radio.aspx

just might meet the requirements you listed.

Before you buy anything though I'd ask if you already have an AM-FM tuner on your stereo that has external antenna terminals for each. If so, just try adding a long wire antenna. Here's a site with some info on that topic.

http://www.angelfire.com/mb/amandx/longwire.html

Google longwire antenna and you'll find a lot of good info out there on them. Shouldn't cost very much at all to construct one of those and you just might find that the dramatic improvement in what you hear is enough to avoid buying another receiver.

Good luck.

Jim "NN4JW" Wagner

[tbn.al]

Saw this one on clearance at Radio Shack while I was shopping for an HD. Mixed reviews. But you can always take it back.

http://www.radioshack.com/product/index ... ab=summary" target="_blank

[rocksanddirt]

likely it is set up with a good antena design.

If this is for the shop/barn go with a Grundig or Sangean multi band radio (quite nice many of them for $100 to $200) and a long piece of copper wire strung from high up the wall to a tree (50' to 100'). This will give you tremendous reception, and allow you to fine tune in the gentle signals you are looking for.

[lgb&dtuba]

comments, please:

http://www.ccrane.com/antennas/am-anten ... tenna.aspx

A wire antenna will do a better job and cost you maybe $15.

[lgb&dtuba]

Why does my 2002 Corolla factory radio have such great AM reception in all sorts of conditions?

It's probably just a better designed radio than the others you are comparing it to. AM radio has been basically a "throw away" for many years and corners can be cut on the circuit to build it cheaper. One less RF amplification stage for example is a common way to "save" components.

Someone mentioned Sangean radios. Sangean used to make a portable shortwave radio for Radio Shack (DX-440). I've owned that one for many years and it's a good radio. In fact, there's one up on eBay right now.

http://cgi.ebay.com/Realistic-DX-440-AM ... 1|294%3A50

[The Big Ben]

1. I have a GE Superradio III and it is fabulous. It is designed for AM reception and has a very large speaker. Runs on batteries or AC power (built in- no wall wart) Uses D batteries which last forever even if you play it all day. Nice to have down in the bunker. No flash. It was discontinued last year so you might be able to get one if you look. About $80.

2. Look for an old five tube kitchen radio. If you find one, play it before you buy it and, if it has a loud hum, pass it by. That's the power supply going bad.

3. AM car radios can be good because the antenna, when properly mounted, is good. The aerial sticking up makes one half of the antenna and the base of the antenna grounded to the body makes the other half of the antenna (ground plane). If the antenna base is not well grounded to the body, there will be lot of static and it works poorly. Frequently, the radios are designed with more gain because they are not using a really long antenna.

[The Big Ben]

Here's what I would *like* to own *if* it exists:

A radio with extraordinary AM band reception including

- nighttime "directional" signals
- highly resistant to florescent lights/computer/vacuum/motors, and other electrical interference
- pulls in and locks in to "marginal" signals
- affordable (but doesn't have to be cheap)
- possibly refundable, if it doesn't live up to its brag
- 110 AC, DC/battery, or 12V DC auto current

Directional? Fuggedaboutit. A directional antenna for the AM broadcast band that would have any capture size would be, well, very large. Think hundreds of feet. Or a phased array of vertical antennas.

If you are thinking of a yagi or a log periodic, I agree. However, a directional loop antenna will allow the listener to null out interference. A problem with AM Broadcast band is that the channels all are shared and sometimes they come in on top of each other. A directional loop could be moved to remove one or more of the offending signals.

I have a feeling Joe is just looking for an AM radio to sit on the shelf and be listened to and is not looking to become a major radio listening geek.

[Dylan King]

http://www.ccrane.com/radios/am-fm-radi ... index.aspx

[Rick Denney]

However, a directional loop antenna will allow the listener to null out interference. A problem with AM Broadcast band is that the channels all are shared and sometimes they come in on top of each other. A directional loop could be moved to remove one or more of the offending signals.

Nah. The noise that causes problems includes static crashes and power line noises, and those are ubiquitous with AM at these frequencies.

And listening to sky-wave propagation at night will also fluctuate in and out with band conditions. That's true no matter how much you spend.

The long-wire antenna is really the best way to go. You might get some directionality from a traveling-wave antenna such as a Bevarage, but it will have to be several multiples of the wavelength to get directionality, and the wavelength for the AM band is 1000 feet or more. Look at the towers used by AM stations--they have to have an array of vertical towers that are phased to increase gain in some directions and null it out in others. Only the designated clear-channel stations can run high power on an omnidirectional single tower. WOAI in San Antonio uses vertical phasing with a vertical dipole arrangement on a very tall tower (about 2000 feet), but I think that's even beyond Bloke's resources.

A long wire (the longer the better, but it will never really be long enough) will work best.

By the way, the little computer-control Ten Tec radio I suggested has DSP filtering. But I have not tried to listen to AM broadcast with mine. Most ham radios are attenuated in the AM band to prevent a strong local broadcast station from overloading and desensing their front ends. It may be true of the RX-320--a call to Ten Tec would sort that out. But that's actually the cheapest radio receiver intended for general use (particularly for shortwave AM) that has decent receiver features. It still may be overkill for Joe but he didn't exactly lay out his requirements.

Many older car AM radios actually had very good receivers in them, but it's been a while since that was generally true.

Rick "not thinking any sub-$100 portable is going to be especially good compared to other sub-$100 portables" Denney