product review 0425
mweinberg
Choyong LC90 Multi-Band Smart Radio
1 day ago — This is more of a quick-start guide than a user manual, and much is left unexplained. The. LC90 desperately needs a detailed manual, even if it is available ...
13 hours ago — This is more of a quick-start guide than a user manual, and much is left unexplained. The. LC90 desperately needs a detailed manual, even if it is available ...
QST Review - April 2025 574 KB
Choyong Radio LC90 Choyong LC90 Multi-Band Smart Internet Radios | DX Engineering
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Document DEVICE REPORTcyr-lc90 etChoyong LC90 Multi-Band Smart Radio Reviewed by Steve Ford, WB8IMY [email protected] Receivers that combine over-the-air broadcast reception with the ability to play audio from internet "radio" sources are not new. However, the Choyong LC90 is one of the first to include shortwave broadcast coverage among its listening options -- and do it all in a package just 6 × 1.5 × 4 inches and weighing slightly less than a pound. Adapting to Change The age of the internet has been hard on shortwave broadcasters. With the proliferation of smartphones and other internet-connected devices, most listeners no longer turn to shortwave for news and entertainment. In response, the overwhelming majority of shortwave broadcasters have left the airwaves in favor of streaming their content over the internet. The same trend is beginning to impact AM and FM broadcasters, though not as dramatically -- yet. With the LC90, Choyong has chosen the "If you can't beat them, join them" approach. The LC90 offers medium-wave AM reception from 522 to 1710 kHz; FM reception between 64 and 108 MHz; AM and SSB shortwave from 2.3 to 26.1 MHz, and long wave from 153 to 279 kHz. But in addition to its radio features, the LC90 offers two methods of tapping into internet audio streams: Wi-Fi and 4G cellular. The LC90 can even establish a Blue- tooth link that allows it to function as a wireless speaker for another device such as a smartphone. Unpacking The Choyong LC90 comes nicely packed within a formfitting foam block that's nestled inside an attractive outer box. In addition to the radio, the package includes a USB-C cable (used for battery charging and firmware updates), a cloth carrying bag, and a tiny manual. I suspect many QST readers will need eyeglasses or magnifying glasses to read the manual. The alternative is to download the PDF version from the Choyong website and then enlarge the text on your computer monitor. 42April 2025 QST www.arrl.org Reprinted with permission, copyright ARRL I'm sorry to say, however, that these efforts will not be well rewarded. This is more of a quick-start guide than a user manual, and much is left unexplained. The LC90 desperately needs a detailed manual, even if it is available only as a PDF. Speaking of the Choyong website, the address shown in the manual links to a site with Chinese text only. Unless you can read simplified Mandarin fluently, the better destination is www.choyongradio.com. Outside and Inside A bright, colorful screen occupies a 2½-inch (diagonal) space on the right-hand front panel. Beneath it you find a number of pushbuttons that have somewhat intuitive functions according to their labels, though a few are confusing and not well explained in the user manual. The functions of some buttons apply exclusively to the LC90's internet features, including the sizable MENU button. (It is used to access the directory of internet "radio stations" and, oddly, the upper/lower sideband functions for SSB reception.) The left-hand portion of the front panel houses the speaker system. Rather than a single speaker, there are two speakers and a woofer membrane. The result is surprisingly impressive, as I'll describe shortly. On the opposite side of the enclosure there are three knobs: a volume control, a coarse-tuning control, and a fine-tuning control. Adjacent to the tuning knobs are 3.5-millimeter jacks for an external antenna and headphones. On this side of the radio there is also a USB-C port for battery charging and data transfers. Along the bottom edge you encounter two small slots: one for a memory card (the LC90 can accommodate up to 32 GB of storage) and another for a cellular SIM card. The telescopic whip antenna extends to 40 inches in length. According to the manual, the LC90 also has an internal ferrite-bar antenna. I was curious about its size and placement, so I grabbed a torque screwdriver and disassembled the rear panel to take a peek. As you can see in Figure 6, there is indeed a rather small ferrite-bar antenna adjacent to the speaker bay. You'll also see an inconspicuous circuit board in the lower left corner of the image. All of the LC90's radio components are on this board. Most of the remaining interior space is devoted to the speaker system and the rechargeable batteries. The battery set consists of two type 18650 lithiumpolymer cells (see Figure 7). At first glance they look like AA batteries, but the 18650s are ¾ inch in diameter and 2½ inches long, making them bigger than AAs. Their combined capacity is 5000 mAh, which provides up to 48 hours of continuous operation. The batteries are replaceable, but you will need a torque screwdriver to remove the access panel. On the Air A 3-second press of the red power button brought the radio to life. A quick press of the FM button brought me to the FM broadcast band, where the reason for the speaker system design became obvious. As I increased the volume, I was treated to audio fidelity that surpassed anything I had ever encountered in a radio of this size. The bass frequencies were full bodied, and the mid-range and high-end frequencies were clear and crisp. With 15 W output (according to the manufacturer's specifications), there was plenty of audio power to spare. The LC90 provides FM stereo reception when used with headphones, though the manual doesn't mention this and nothing in the display indicates when stereo decoding is taking place. Nevertheless, when I plugged in a set of headphones and tuned to a stereo broadcast, I was rewarded with excellent right- and leftchannel separation. The LC90 exhibited good sensitivity in the FM broadcast band overall. With the telescoping antenna I was able to easily pull in distant stations. Bottom Line The Choyong LC90 radio is feature rich and compact with great audio. It covers many bands, and with its internet capabilities you can listen to endless online content. Figure 6 -- The interior of the Choyong LC90. The modest ferrite-bar antenna is visible at the upper right. At the lower left is the circuit board. www.arrl.org QST April 202543 Reprinted with permission, copyright ARRL Figure 7 -- The LC90 is powered by two rechargeable type 18650 lithium-polymer batteries. They may look like AAs, but they are noticeably larger. While exploring the band I made effective use of the LC90's search feature. With a long press of the FM button, the radio begins scanning the entire band and logging signals in consecutive memories. This clever search function is also available for medium-wave and shortwave frequencies. While testing the search function on shortwave, I discovered that the LC90 is capable of tuning beyond the specified frequency limit of 26.1 MHz. The scan blew right past that frequency and continued all the way to 29.999 MHz. As sterling as FM reception was, medium- and longwave reception was a serious disappointment. The internal ferrite-bar antenna was largely ineffective. In fact, it exhibited no directionality when I rotated the radio. I was able to receive only a couple of local AM broadcast stations, and those were much weaker than they should have been. I heard nothing but noise on long wave. Shortwave performance was significantly better. With just the telescoping antenna I was able to listen to several broadcasts, as well as National Institutes of Standards and Technology station WWV at 10 and 15 MHz. Attaching an external antenna greatly improved shortwave reception, which was to be expected, although it did little to help medium wave. You can select from various receiving bandwidths, but the manual doesn't explain how to do this. By accident I discovered that pressing the FINE-TUNING knob allowed me to scroll through, and select, preset bandwidths. I'm afraid the LC90 misses the mark, however, when it comes to SSB reception. I was able to eavesdrop on several amateur SSB signals, but the lack of frequency stability in this mode was bothersome. Within seconds after tuning in an SSB signal, the radio began to drift, 44April 2025 QST www.arrl.org Reprinted with permission, copyright ARRL Figure 8 -- Using the LC90's Wi-Fi capability to listen to an internet audio stream from WUNH in New Hampshire. requiring frequent adjustment of the FINE-TUNING control to keep the voices sounding normal. Internet Radio If you grow tired of listening to radio, the LC90 allows you to surf among thousands of audio streaming sources available on the internet. As mentioned previously, you have two internet connection options: Wi-Fi or 4G. For this review I chose Wi-Fi. Having cellular access is handy when Wi-Fi isn't available, but that requires installing a SIM card, usually at an additional charge from your cellular provider. As with most Wi-Fi-connected devices, the first step is to enter the password of your chosen network. This process is cumbersome with the LC90, but you only need to do it once (unless you change to another location with a different network). You enter the password by using the tuning knobs to scroll through the alphanumeric combinations, selecting each letter or number by either pushing on the knobs or pressing the frontpanel OK button. Once the LC90 is connected to the network, a single press of the MENU button opens a built-in database of internet streaming sources. Sources are sorted by region, country, and area -- such as a province or state. Again, you select by pressing the tuning knob or the OK button. The database is vast, and you can spend a great deal of time just bouncing from one stream to another. My first stop was a stream in New Hampshire (see Figure 8), but I soon found myself sampling music from Nigeria, China, Australia, and much more. Some streams were of better quality than others, both in terms of audio and reliability. The database appears to have been compiled by Choyong; it isn't one of the better-known online lists. The manual doesn't mention whether the database is updateable. On the front panel there are shortcut keys that purport to take you directly to music, news, or podcasts. In my experience, however, the buttons merely brought up lists of sources that may or may not have the specified content. For example, choosing WALM in the podcast list brought me to a pleasant classical music stream, but not a podcast. The LANG button did a respectable job of sorting streams by language, which was convenient. A long press of the LANG button triggered a voice-recognition search feature, but while a microphone icon and a text prompt appeared in the display, I was never able to get this feature to work. Maybe the LC90 didn't like my voice! Favorite internet streams, as well as over-the-air radio frequencies, can be added to memory by simply pressing the button with the heart symbol. Entries can be removed from the list, but it takes a little investigation to figure out how to do it. You can also manually enter the URLs of internet streams not in the database. Conclusion The Choyong LC90 is rich in features, but the overall design remains a work in progress. There are features that need revisions to make them more effective and "friendly." And then there is the abysmal medium-wave sensitivity and sub-par SSB stability. With the ability to Lab Notes: Choyong LC90 Multi-Band Smart Radio Receivers that cover a wide range of the AM, FM, and multiple shortwave bands have been around for many decades. The Choyong LC90 is one of several available modern versions of this type of receiver. With added features such as Bluetooth, .mp3 playback from a TF card, and quick ways to access podcasts and other pre-programmed internet music and news channels, the LC90 offers more to listen to than receivers of old. Although the LC90 has all of the above-mentioned features packed into a small and relatively inexpensive form factor, some receive capabilities do not perform nearly as well as products sold specifically for amateur radio use. While performing tests on the LC90 in the ARRL Lab, the receiver exhibited some odd anomalies that prevented us from making any usable measurements on the unit. The front end of the receiver overloaded quite easily at lower levels than expected. It was observed to have some frequency drift as well that caused problems trying to measure basic things such as sensitivity. The LC90 does receive OTA signals on all the modes/bands as specified, but don't expect it to perform as well as a receiver designed for amateur use. -- George Spatta, W1GKS, ARRL Lab Manager upload new firmware, it is possible that many of these shortcomings may be addressed in future iterations. Manufacturer: Choyong Radio, www.choyongradio. com. Price: $249. Available directly and on https:// amazon.com. www.arrl.org QST April 202545 Reprinted with permission, copyright ARRLAcrobat Distiller 25.0 (Windows)