AM Radio DXing

Off-topic Chatter
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I was gratified to see a thread like this come up. What’s below is a collection of disjointed AM-related thoughts… kind of long but put it all in one post, so if you get bored no need to complain, just skip.

The Select-A-Tenna would be called ‘what’ kind of antenna? Is it a ‘loop’ antenna, or different from a standard loop antenna (if so, what is this kind called)? To me, a loop antenna needs to be plugged in, and these types don’t.

Anyone know if bigger/more powerful versions using the same concept? I’ve seen the Select-A-Tenna, Terk, and Kaito (or is it also Teksun?) sold on Amazon. I’m thinking about buying the Terk or Teksun, but wondering if there’s anything better out there. Even if I have to plug in the antenna (less-desirable, but I have radios which can accept antennas). I considered getting the CC ferrite used, but so far haven’t had the patience/priority to try to bid on one on Ebay. Being that they require power, it’s a turn-off. Is the C.Crane twin coil worth the price and inconvenience? I like the Select-A-Tenna types because I could use it on radios in various places, such as an old clock radio I use in the kitchen quite a bit for AM.

There is a guy in Australia hand-making antennas on the select-a-tenna principle, but the sizes range from “large” to “larger”. UPDATE: while writing, I found him. Don’t think he sells his full complement on Ebay, but maybe more items now. Seller ‘cygnus4444’. Perhaps “PK’s Loop Antennas” elsewhere on the net? UPDATE: Yes. He has a proper website, but still that horrible PDF ordering form, no shopping cart:

By far his most popular Ebay item:

There used to be a US or North American seller who handmade even larger ones (more like “hoop” vs “loop” antennas), but I think he is deceased so they are no longer made. I think the demand is there; someone should start building larger/better performing AM antennas out there for the US market, including big ones like he did. That’s not my forte, so anyone have at it. I recommended the idea to a friend of mine who knows a lot about electronics and was looking for different ways to make income preferably from home, but he turned down that idea (like many ideas I gave him which I don’t have the skills for, but he does). For awhile on Ebay, a somewhat homemade looking box-like thing was being sold as an AM ‘loop antenna’, which, it is my understanding, was not what it claimed to be, and was of questionable effectiveness. I just checked and don’t see it sold anymore.

For you Coasties, I’m in the southern US but can only pick up the show from 2 (luckily) closely-spaced stations from I think somewhere near Chicago(!), and the other one is out of Tulsa. 1190 and 1200, I think. When one fades out, the other one usually is available, and vice versa. A little inconvenient, but they’re so close-together, it kinda works. Could never figure out why they fade in and out like that, I’ve always assumed it’s clouds, but don’t know. It’s too annoying to be a regular listener. I’ve wisely anyway switched to Alex Jones/Infowars.com for my primary daily media & analysis. They have a free call-in listen line, plus free MP3 download… neither of which are free and/or available with Coast. After years of doing the following, I wholeheartedly recommend physically disconnecting your TV service (antenna or pay service) so you’re not even tempted. Big Media are SO obviously controlled, one of the things we can do is just walk away… and get our info from less-imperfect sources, at least ones that are not deliberately wrong, I’m meaning. I do miss seeing documentaries, but the fact is, in the ensuing years, I’ve seen much more worthwhile documentaries on the internet for my time. Not as entertaining as watching the saga of a family of meerkats on Discovery that I’d never look up online, but much more important content. Turn off your TV!

Found some very expensive loop antennas! Ranging from $500 to 1000, though it’s not even clear if they could be used for medium wave/AM:
Over $1000, apparently for testing purposes, but looks a lot like those ‘hoop’ antennas the deceased gentleman used to make IIRC:
http://www.ebay.com/itm/ETS-Lindgren-6512-Passive-Shielded-Loop-Antenna-10khz-30Mhz-NICE-/331908666886
$500 loop antenna from Japan: For your money, you get very little info about what you’re buying!

I imagine something like this is a waste of money? This item is new to me. Seems to me to be an amplifier for AM antennas?? Cheapest price on Ebay $18. (Sidenote: Degen seems to be well-respected for inexpensive radios, too bad their digital AM pocket radio is not really usable for the US market or I’d have one.)
“Indoor Active Soft Loop Antenna for MW&SW Radios w/ Antenna Jack DEGEN DE31MS”
http://www.ebay.com/itm/Indoor-Active-Soft-Loop-Antenna-for-MW-SW-Radios-w-Antenna-Jack-DEGEN-DE31MS-BC-/360893279758

I learned an important lesson after buying used a swanky 1990s Denon radio-only deck component (and I used decent antennas). I love 90s Denon stuff, but not that radio deck. It gets the worst AM and probably FM reception of any radio in my house. I learned that being able to CARRY AROUND your radio is very important. Moving it from place to place, and getting it away from other electronic equipment, ended up seeming more important than the “quality” of the radio, or even apparently the antenna (if said antenna was in close proximity to the interference and/or bad location). I live in the boonies and kind of in a gully. I went so far as to take a long piece of lamp cord and string it outside and into my window one fine day, to see if it would help me on AM or FM (into the Denon radio deck, in fact). Surprisingly, it didn’t. Very disappointed, looking for solutions. I’m not a radio or electronics expert.

I’ve nearly bought several models of Sangean radios, but they are so super-stingy on their number of presets, I’m not going to spend that kind of money on something with, last I checked, 10 or even just 5 presets. For the extremely insignificant cost of non-volatile memory, there should be tens of presets if not hundreds available. I’ve seen super-cheap Chinese schlock which does, so Sangean can too. Plus I’ve seen multiple reviews of Sangean radios just dying for no apparent reason. All my radios from the 1980s still work!! I know it’s not apples to apples, and there’s the horribly counterproductive RoHS, but still. When buying, I’ve become scared that the fancier something is, especially electronics and digital electronics, the more I’m worried about it dying. I only have one C.Crane product, an FM transmitter I bought as an “Orphan” (customer return). It worked horribly, even after the ‘secret mod’, and later the cord dried out and cracked. I should’ve returned it, but I thought the bad performance (range and/or distortion) was my fault (improper tweaking), or unrealistic expectations. Today, there are amazing digital Chinese FM transmitters meant for car use that can be bought for just a few bucks shipped, and can be modded to have a better battery and/or antenna, which even with the stock antenna far outperform my bulky C.Crane box (admittedly, this is years later, but they’re still selling it). IDK if those cheap little imports follow the US rules, but they sound pretty good, and definitely have better range than my C.Crane; the battery is really the main problem unless there’s a ton of interference like being up on a hill in an urban area. (Using USB charging from car power introduces noise, so their mini pillow li-poly battery is their weak point.)

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I used to wonder too. It’s because the signal bounces off the atmosphere and as conditions change the height of the bounce changes. The “skip” can sometimes “land” either ahead of you or behind you depending on how high the bounce is at that particular instant.
Also for some medium range stations, you might receive both a skip signal AND a ground signal. Because the skip signal travels further, the 2 would come in out of phase. As the skip component waxes or wanes, the mix can sound strange. “Phasing” was a technique used in the late 60’s by some Rock Groups. Small Faces and the song “Itchycoo Park” comes to mind

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Interesting! So it sounds like you’re saying it’s actually the ionosphere itself going slightly up and down, not clouds coming through a certain area. That makes more sense to me. I know the Jet Stream shifts around, including going up and down, so why can’t other parts of the atmosphere? Hm.
I do know about phase shift in audio (intentional and not), but now I’ll have to pay attention to the phasing effect of distant AM channels. Thanks!

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Lots of interesting phenomena on the AM BC band. Skip is the most noted. It’s named that because there’s a range between groundwave and ionospheric bounce which the signal “skips” and cannot be heard. Skip distance varies with frequency. The ionosphere is inconsistent but when it’s right a 3 hop skip signal can be strong though you normally lose reception after the second hop. It can also come in best from a different apparent direction. Groundwave in daytime can go past line-of-sight, it hugs the earth some over the horizon. Then there is “grayline” propogation which happens as the sun rises between you and the station. It’ short-lived but can log you stations you’d otherwise never hear. There’s also “selective fading” due to phase-change or the signal getting nulled by multiple skip paths. Some high-end rcvr’s can handle that with DSP, but sometimes you can turn the antenna and follow it. And then there’s AM Stereo (at least in the US) in a few different formats with a handful of stations still broadcasting that way! Special rcvr’s are needed to decode it but any rcvr can hear them monaurally.

Most AM rcvr’s use a ferrite rod antenna so rotating the set can incresae or decrease the received strength. It can also be used to null out a strong signal to hear a weaker one. The old DF marine radios had a rotatable bar on top concealing the rod antenna. You can wrap several rounds of wire near the plain end of the rod to connect an external wire antenna to for better reception of weak signals but it tends to cause overload if you have a BC transmitter nearby. Occasionally grounding the negative battery terminal can also increase sensitivity.

Sets which have selectable “sideband” instead of a BFO can sometimes grab a weak signal when a stronger one intrudes. Wire antennas don’t really perform well until they’re 1/4 wavelength or more in length which is impossible for most of us so just make those as long as you can. The AM BC band “hears” about all the electrical interference around you. On your favorite battery-powered set listen around the dial when the power goes out in your neighborhood and you’ll be amazed at how much less background noise and trash there is.

Trivia Time! Bob Crane of CC Radio fame got his start by selling “Selec-tenna’s”. I’ve never tried one but they might be fun. It’s on the bucket list for sure. Something similar can be achieved by placing a cheap transistor set near the one you are listening to and moving around the dial on the cheap set. It will usually cause a frequency shift on your receiver but you can tune up and down till you find it again. If your’e well-coordinated you can work both dials together. This technique can also allow you to hear SSB signals on an AM only radio through introducing the missing carrier through IF harmonic radiation!

So you’re trying your best but background hash is all over the dial. Take a portable set outside by the power poles and listen as you whack the pole with a hammer. If the noise goes haywire there’s a bad power line insulator on that pole. Go to several poles past the closest one as this can be powerful noise which carries far.Sometimes they’ll fix it if you call them with your report.

I doubt anyone is using a tube (valve) type rcvr, but beware that some cheaper ones had a “hot” chassis where one side of the AC power is connected directly to it. As old as they are some of these have lost the back panel over time making them dangerous.

Sometime in the 90’s (or a bit later) Sangean changed factories and their radios became crap. They supposedly build decent one’s now but research the build date on the older ones when buying used. CCRadio even went to other companies because of that- Sangean did most of their sets back then.

If you’re wealthy enough there are Ham rigs and high-end desktop rcvr’s with DSP which will blow away the portables we’re discussing here. There’s even SDR (software defined radio)which plugs into your computer to do amazing things. But even with all that, there are some of us who take greater pleasure from listening to an old analog set with all it’s shortcomings because with those it’s operator skill and knowledge rhat logs stations, not fancy programs and digital circuits. I’ve found several digital sets can’t tune a signal as well because the RX or TXor both are slightly off.

There used to be several SW stations broadcasting folks like Alex Jones along with some AM stations joining in. There used to be shows like Dr. Demento, American Top 40 with Casey Casem, Charlie Douglas and the Road Gang on WWL, the Mexican Rock-and-roll super-stations beamed north, and so forth which made AM very interesting. What’s left of those is mostly online now and more’s the pity. US AM is mostly sports-talk and “news radio” now with little to offer those of us who don’t need to be told what to think and who aren’t interested in sports. And a lot of it is now in Spanish. We’ve lost what used to link our greater community together and gave us music we liked for free wherever we went. There’s little profit in the AM radio business anymore and nobody dares to be different for fear of bankruptcy if they lose even a little market share. Video killed the Radio Star and the Internet and personal music devices are killing what’s left of broadcast radio. There’s only a handful of SW and unique AM broadcasters anymore, and FM BC isn’t too far behind. Enjoy what’s left of it while you still can.

Happy DX’ing!
Phil

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Also note AM radios are good to test for radio frequency interference — CFL and LED lights, and switching (the smaller kind) wall wart transformers are common sources of radio noise aka “electronic smog”

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@ boaz (and other curious ears subsequent) :
From what I’ve read, seen, heard-talk-of, or otherwise tripped over, most of us AM DXers actually live indoors. In case you too are such an individual, you want a good portable and nice batteries for the hobby.
With the noise levels in residential communities having become what it is nowadays, using radios that plug into the wall for anything other than local is useless in the daytime for browsing, and even at night. I’ve found no other way to eliminate the daytime dial racket except to get in the car and find some clear spot in a field, or listen at home with the batteries alleviating the man-made neighbourhood commerce noise from utility lines, other people’s computers, traffic lights, buzzes and hums from wherever, etc…
The old standby radio here is a GE Superadio 2. But here’s a site where you might get some more of a selection and more intelligent answers than I can offer.

https://www.radiodiscussions.com/forums/dx-and-reception.769/

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Please enjoy your time here, Steve_Green!