TECSUN AN-48x AM/LW/SW Active Loop Antenna

An inexpensive new antenna from Tecsun has just hit the market and after using the antenna over a period of many days and with several different radios I’ve figured out its strengths and weaknesses and will describe them as we go along. I found several cases where reception was indeed improved and the improvement was real, but at other times the results were less spectacular.

The AN-48x is a logical successor and is similar in performance to the now-discontinued Aadwards A38-LMS Antenna which I’ve learned was made by Degen, who also offered a series of similar antennas in their Degen/Kaito DE31/DE33 series of loops over the past several years.

One improvement here is the unusually wide range of connection possibilities the AN-48x offers. It is supplied with output adapters for 1/8” mini-plug, BNC, RCA, clip leads and of course, a ferrite sender to radiate AM/LW signals directly into most radios. They also include the same style ” Base Station” introduced with the Aadwards which is a cleverly designed plastic stand which holds the ferrite sender against the back of small to medium-sized radios while holding the radio at a convenient angle. It would be nice if this stand actually snapped together…as it is, the two pieces merely rest on one another so it will come apart when you lift it up unless you grab both pieces together.  A small nit to pick I suppose because it is a cool accessory.

Current price (December 2019) at https://www.anon-co.com/product/tecsun-an48x-antenna  is $27.99 plus shipping.

Description: In the Box:

English User Manual
Amplifier with antenna wire
Control box with 1/8” miniplug output cable
BNC Adapter
RCA Adapter
Alligator Clip Adapter
Ferrite coupler
Base station to support small to mid-size radios and the ferrite sender
Suction cup
Hanging clip
Loop extension rod

Band Coverage:
Longwave: 120 ~ 400 kHz

Medium Wave (AM): 520 ~ 1700 kHz

Shortwave: 3500 ~ 20,000 kHz

The AN-48x runs on two AAA batteries (not included). The antenna itself, like its predecessors, is a loop of wire and a telescoping rod which holds in in its correct shape. At the top you use a clip or suction cup (supplied) for mounting the loop. At the bottom of the antenna is a LW/MW/SW band selector switch which plugs into a 16-foot cable. This cable terminates in a mini-plug which is connected to the Control Box, which outputs to a short mini-plug cable which can be plugged directly into a radio or used with one of the several supplied adapters or the ferrite sender.

Control Box controls include an On/Off slider switch, LED Power indicator plus Tuning and Gain knobs.

Performance: Here we have what one would expect from such an inexpensive amplified antenna and in fact, performance is very close to what I found with the Aadwards and Degen/Kaito antennas which came before. In a nutshell there are situations where this antenna may give greatly improved reception and others where it won’t help at all and can even degrade reception. Understanding how it works, along with its strengths and weaknesses is key to getting the most out of it. Although I tested it briefly on LW just to be sure it worked (it did) I am not a frequent LW listener and focused my attention on SW and AM (MW).

I tried the AN-48x with several kinds of radios ranging from small, travel-sized portables to large highly sensitive radios and as is usually the case, the less sensitive the radio, the more this antenna helped it, but I must say I got a few improvements here and there even with some of my best radios. Here’s what I learned about how it works which may guide you to getting the most out of this antenna…this information also applies to the Aadwards AN-38 LMS.

Antenna Placement is what it’s all about. In most cases, if you set up the loop antenna right where your radio is located you are not likely to get much improvement. You may get some benefits but not what you could get with a little more time spent experimenting. The idea is to try different antenna locations and aiming to find a position where noise is minimized while signals are maximized. I also found that aiming the antenna to null noise can be very critical whereas aiming to increase signal gain is somewhat broader…this directionality varies with frequency. Sometimes you can simply aim the antenna to null noise but at other times the signals did respond to aiming quite a bit. It was usually more directional on AM than SW – again fairly typical.

Tuning on the Control Box is finicky. As I found with the Aadwards, the Tuning knob is erratic and tuning does not seem to correlate with the frequency you are tuning to. On any given station I found that much of the control range resulted in loud hiss…full signal reading on the radio’s meter (if it had one), but no audio other than hiss. Slowly rotating the knob counter clockwise from maximum clockwise, at a certain point the signal would pop in, then fine adjustments were used to maximize the signal to noise ratio. This was more touchy on SW than on AM but it occurred on both bands. The Tuning knob on mine was also erratic just as with the Aadwards, often giving bursts of static as it was rotated, but with patience I learned how to work around that. Since the Aadwards was just like this Tecsun in this regard I have to assume it is not a sample defect but a design limitation.

I will say that there were some signals (both AM and SW) that were noticeably clearer with the antenna but some signals were the same or worse. There was always a big increase in signal level as observed on a radio’s meter but this did not always equate to a clearer signal…this super strong signal could be the same or noisier than without the antenna. Again, placement of the loop sometimes helped it provide a clearer signal. To get an advantage from this type of antenna you have to be willing to experiment with every variable and sometimes you will get a huge boost in reception quality…other times you won’t.

Is it worth it…should I buy one? I suspect some people will find the Tecsun AN-48x fun to experiment with while others will find it tough to use.  Clearly a sub $30 antenna is not expected to perform as well as a $300 antenna, nor would one expect it to help very sensitive radios as much as it might help lesser radios. But I will say the Tecsun AN-48x is at least as good as the similar loops which preceded it and it can certainly help in some circumstances, especially where it can be located away from your radio in a spot where reception is better or noise is lower. If you are a radio hobbyist and especially if you love playing with antennas you will appreciate the connection flexibility it offers and you will find ways to get the benefits it offers. If you already have an arsenal of antennas you will not find it a breakthrough, but you may find it a fun tool to have at your disposal for those times when it does help. And for the price of admission it’s hard to fault it.

Jay Allen

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