It is one of Murphy’s laws, we think, that you can’t get great things when you need them. Back in the heyday of shortwave broadcasting, any of us would have given a week’s pay for even a low-end receiver today. Digital display? Memory? Digital filtering? These days, you have radios, and they aren’t terribly expensive, but there isn’t much to listen to. Making matters worse, it isn’t easy these days to string wires around in your neighborhood for a variety of reasons. Maybe you don’t have a yard, or you have deed restrictions, or your yard lacks suitable space or locations. This problem is so common that there are a crop of indoor antennas that seem attractive. Since I don’t often tune in shortwave and I don’t want to have to reset my antenna after every storm, I decided to look at the Tecsun AN-48X along with a YouLoop clone from China. Let’s start with the Tecsun.
In the Box
The antenna is not terribly cheap at about $50 or so, but there’s a lot in the box. The business end looks like something you’d wear around your neck. A small box has a switch for three bands — LW, AM, and SW. the two wires coming out of that box form a loop. You can stick the loop to something using a suction cup or a hook. There’s also a little bar that looks like a standard telescoping antenna but it has two plastic clips on the end. You use this to form the loop into a diamond shape with the telescoping rod about halfway.
At the bottom of the box with the switch is a standard 1/8″ jack. A cable connects that jack to a similar jack on the control unit which is about the size of a large pack of gum and has two AAA batteries inside. That box has a switch, two knobs, and a pigtail with another 1/8″ jack.
If your radio takes a 1/8″ plug for an antenna, that’s where you connect it. If it doesn’t, you have a few options. The box contains pigtails that convert the plug to BNC, RCA, alligator clips, or a ferrite bar that can couple to a radio’s internal antenna. You probably need SMA for a modern radio, so you’ll need an adapter. There’s also a plastic stand that can hold your radio and the ferrite bar if you are using it.
The knobs on the control box control the gain and tune the frequency of the antenna. Other than the switch close to the loop, all the other controls are on the control box, which stays close to your radio. So, as long as you don’t care about jumping between LW, AM, and SW, you don’t need to access the loop part during operation.
A Few Tests
I decided to try the antenna at a few different times a day in a few different locations. I used an old portable DAK shortwave receiver and also a more modern SDR receiver.
For the first test, I hung the loop on my upstairs stair rail and let the cable drop down to the first floor. During the day, WWV was barely audible, and there was little else to hear outside of noise. Granted, this was indoors. The signal level control didn’t seem to do much. The tuning frequency knob reminded me of a regenerative receiver control. You could hear the device oscillate, and just past the oscillation, you’d get the best signal. It made me wonder if the inner circuit was, in fact, a regenerative amplifier.
The portable shortwave uses a regular jack, but for the Malachite, I had to use a BNC to SMA adapter. Neither radio could pull much out. Nighttime reception was a little better, but not much.
The Great Outdoors
Unsurprisingly, the device worked a little better outdoors. I hung it from an exposed beam on a pergola, and at night, there were a few fairly clear signals. During the daylight hours, WWV was elusive, but the Voice of America and Radio Havana — not too far from Houston — were easy to copy, especially if you understand French. I even managed to catch a few faint snags of WWVH.
The video below shows a few audio clips of the results. Forgive the outdoor glare on the screen in the first clip. I omitted the clips with music that YouTube might flag, but you get the idea.
I also tested a YouLoop clone. This worked almost as well as the Techsun, but not quite as well. However, there was nothing to fidget with on the frequency.
The YouLoop
The YouLoop has an interesting idea. It uses coax for the loop and configures it like a Mobius strip so that it is kind of, an infinite loop. At the bottom is a balun with three connectors, and at the top is a phase inverter. That sounds fancy, but it really is just a box that connects the inside of one cable to the outside of the other. The antenna came with a powered preamp, although if your radio has a preamp, you probably don’t need it.
It is handy that it just works, and the coax sections are stiff enough to be easy to handle when you want to hang it from a branch, for example. However, it also doesn’t pack down as tightly, and the boxes are metal, which adds to the weight but is probably better for shielding.
Signals on this loop were almost always lower in volume than the same signal from the Tecsun, even with the preamp. On the other hand, if you don’t need the preamp, this antenna takes no batteries. It is simple enough that you can try it and see if you like it without a major investment.
Observations
While the Tecsun is light, I can’t help but wonder if the shielded feedline might not have helped it. For both antennas, having the preamp close up to the feed point might pay off, although maybe some of the wire between the antenna and the control boxes or preamp becomes part of the antenna. It isn’t, after all, a tuned antenna.
The Tecsun’s control box frequency knob is maddeningly sensitive, but it does seem to help things. Inside the box is a tiny PCB, and I didn’t find any online schematics.
Should you run out and get either of these antennas? If you have other options, probably not. But if you need something, both of them are better than nothing.
If you haven’t had a shortwave radio in a while, they are surprisingly cheap these days. Well, most of them, anyway.
I love all these colorful little loopholes designed to trick God on the shabbat, there’s so many of them. I wonder if using it as part of a radio would in any way violate its purpose. I’d have to consult a rabbi
That’s why God caused alligator clips to be invented.
It’s called an eruv. In Manhattan they use fishing line which is probably not a good conductor.
http://eruv.nyc/
Well… (reading the linked Wiki page) God’s law only prohibited carrying objects between private and public places. It is human (rabbinical) law to limit carrying objects between private and semi-public places, as a safeguard on the first law. What the eruv does is basically have a Rabbi attest that “yeah, this is semi-public, not public, so it can be considered private between the relevant parties, as far as this law is considered”.
Of course, the Manhattan eruv (or any other such wide-area one) does is bring this to its logical and absurd extreme, although I guess it still serves its purpose of keeping the community together.
Shortwave broadcast is pretty much dead, or at least filled with extremely annoying political hacks and religious cranks. Ham radio on the HF bands is still active, of course, although much of that has gone digital because even hams got tired of talking about the weather. People trying to satisfy the need to receive something … anything … probably need to go the SDR route (dongles are exceptionally cheap) and stalk around VHF/UHF/L-Band looking for things like airplane communications, weather satellite images, airplane ADS-B displays, INMARSAT satellite communications, etc. An inexpensive DIY antenna will handle most of that if you can get it up in the clear, like on the roof.
QO‐100 is the new shortwave! 😃
Or maybe not. It’s a new adventure, at least.
Old shortwave transceivers can be used to drive an up‐converter, for example.
10m is supported by most of them. And HF rigs can do SSB, too.
They also can output power in different steps, which is ideal for driving the up‐converter (5W often is max they can handle for input).
Down converters for 10m exist, too, but they’re more rare.
The more common down bands are 2m/70cm, I think.
An SDR can also be used to hear the LNB’s 739 MHz IF.
Really, it’s worth a try.
An 60cm or bigger parabolic dish can carry both the LNB and a little helix antenna, for example.
And North America and Asia might get their own sats soon.
The next one that’s planned is for covering Canada and eastern part of the US, or so I heard.
So there’s hope. Amateur radio will remain alive.
I forgot. Hams also have radio satellites. There are many new cubesats floating around, as well as ISS and good old AO-7.
A circular polarized antenna (helical), like for weather satellite reception, might be a good choice.
Using Heavens Above, it’s easy to keep track of them.
For orbital prediction, it’s also possible to use a dedicated desktop computer.
There are evergreens such as STS+ (DOS), GPredict (*nix), MacDoppler (Mac) and so on.
PS: A few of the old Radio Sputnik (RS) satellites had transceivers on shortwave.
They did use HF bands like 15m or 10m, I vaguely remember.
So they might be a good alternative to earth’s shortwave, too.
My refrigerator, freezer and oven have “Sabbath mode” so that religious folks can use these devices without being punished by fire forever and ever. For the refrig/freezer it allows them to open the door without causing the interior light or cabinet fan to change states. For the oven, it disables the 6-hour maximum run time safety interlock and lets the oven run forever at one temperature setting. The setting cannot be changed. So the religious person sets an oven temp at like 375F right before the start of the sabbath, and then can use the oven all during the sabbath-period without punishment. I think it also disables the interior light.
It’s an interesting idea and I kind of wish I had been able to be involved in the firmware for these devices.
I wonder what the design specifications and tests looked like?
Loophole to salvation, talk about a life hack.
The proliferation of digital devices, especially LED light bulbs has really killed HF receiving in almost any inhabited area by raising the noise floor to very high levels. Try those tests out in a rural area or a campground and you might find very different results.
I agree with the LED bulbs, they’re of really poor quality.
But ironically, the LEDs itself are “okay” – It’s the power supply.
Or the lack thereof. In the models I’ve taken appart, there was just a single diode.
No suppression chokes or capacitors for cleaning the AC or stabilizing power.
It’s almost a crime that something so badly and carelessly made can be sold on the market.
Such an construction should be forbidden to be connected to the mains power grid, for safety reasons alone.
I forgot to mention, there are counter measures. In principle, I mean.
Ferrites can be used to reduce RF noise. These snap‐on models can be attached to power cords or USB cables.
Older USB 1.x era printer cables often had them built in, I remember.
Then, it’s possible to use a magnetic loop antenna for reception.
The models with a variable capacitor can be tuned to a specific frequency/signal and become deaf too the noise.
They won’t hear the electric component in near field, only the magnetic one.
That way, they are immune to man made noise, which usually is electric noise.
It really works!
Last but not least, please give up on RG58 coaxial cable.
Not because of losses, but because shielding nolonger is sufficient.
Man made noise from the neighborhood enters the mantle, essentially.
Consider using RG213, RG214 or one of the modern cable types (H155, Aircell, Ecoflex and how they’re called).
No the noise is broadband not at a specific frequency to be tuned out by a resonant network
I know. But in the close range, the magnetic loop is listening to magnetic field component of an EM signal (radio signal, has both).
If tuned to your desired signal, that signal becomes strong and clear and the background noise goes away (preselector effect, sort of).
That’s because the noise/man‐made‐noise typically consists of electric field component and because the magnetic loop is insensitive to this component. Hence the name.
$50? The price seems to have gone up a little. I use a Kaito version that I picked up for use with my Degen digital multiband receiver whenever I get in the mood to work some wefax. Decent performance for the $10 and sh+h I paid for it a few years ago.
“Back in the heyday of shortwave broadcasting, any of us would have given a week’s pay for even a low-end receiver today. ”
I did. I wasted my pocket money many moons ago. 20 DM, I believe. On an Watson TR 4306. I still regret it.
I still remember how disappointed I was that I couldn’t listen to morse code stations or “hear” weather fax with satellite photos.
If my it wasn’t for my dad who did let me use his Yaesu FT‐101 transceiver to listen sometimes, I had been given up on shortwave listening at the time.
Such cheap pocket radios are a waste. They are too expensive in a different way, also.
They’ll “cost” you happiness and nerves. I still have the cardboard box of the TR 4306 as a reminder not to buy cheap radios again. SSB or a BFO are a basic requirement.
depends on the era we’re talking about, and the definition of a cheap low-end radio. When new, be Degen de1103 outperformed my Sangean 803a, and only cost me $40. Looking on eBay, the same radio is now going for multiple hundreds a decade later.
Well, it can’t be ungodly, at least, if the pope himself has/had a callsign? 🤷
No such thing as deed restrictions for an antenna, not in the USA. No covenant, deeb, HOA etc. can prevent you installing an antenna, not even for something non-commercial such as ham radio.
but an HOA can make things holy hell for an individual trying to asset rights like this.
Yeah but let a hurricane come through and knock down every cell tower every cable pole and nothing left but radio I bet they will beg you to put up that antenna and call for help. HOAs are hypocrites. Let them stew in their restrictions. 73
I thought if you were provided with a free community antenna (“CATV”) connection, outdoor antennas **could** be legally restricted?
Combination of elements for conductor metal to print fundamental fractals, layered printed fractal circuits combined to a solid state layered printed circuit antenna
Hasn’t even got anything to do with this discussion. You seem confused.
I can almost guarantee that a rabbi would prohibit an eruv (if it were constructed with a good conductor) from being used as an antenna. This is because using it for this purpose on the Jewish Sabbath and on major Jewish holidays violates Jewish law as observed by religious Jews. A foolproof method to prevent use on prohibited days would be much more trouble than it’s worth, requiring a calendar/clock system based on the sunset time for each day +/- a specific number of minutes. So a rabbi would likely say “On our eruv electrons don’t roll on Shabbos (to benefit someone).”
All I can say is, back in my teens in Europe, o had a Sharp boom box with a AM/FM/SW/LW selector, It had a telescopic antenna and I used to stay up to the early hours slowly rotating that tuner knob, listening to radio stations from all over the world, morse code and repeating tunes that I had no idea what they were. It was fun and interesting. Now I’m in Florida and FM radio sucks, AM is still useful, but I’m a music lover and streaming is the way to go.
1. I use the Tecsun AN-48X in both active and passive mode. It’s easy to use. It’s sometimes very helpful and sometimes well better than nothing.
2. Cost Tecsun AN48x
I was astonished to read the price of US$50.00 for the Tecsun AN-48x
At the main Tecsun / Degen supplier, Anon-Co.com, it costs about 1/2 that at $27.99 see:
https://www.anon-co.com/product/tecsun-an48x-antenna