{"id":46292,"date":"2020-11-02T08:42:50","date_gmt":"2020-11-02T12:42:50","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=46292"},"modified":"2021-02-05T10:11:36","modified_gmt":"2021-02-05T14:11:36","slug":"a-review-of-the-lab599-discovery-tx-500-qrp-transceiver","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2020\/11\/a-review-of-the-lab599-discovery-tx-500-qrp-transceiver\/","title":{"rendered":"A review of the lab599 Discovery TX-500 QRP transceiver"},"content":{"rendered":"

\"\"<\/a><\/p>\n

The following review of the TX-500 was first published in the October 2020 issue of The Spectrum Monitor<\/a> magazine.<\/em><\/p>\n

Last year, a company out of Russia started dropping hints about a QRP transceiver they were developing called the Discovery TX-500<\/strong>.<\/p>\n

The prototype photos looked like nothing else on the market: it was unusually thin\u2013\u2013only 30mm thick\u2013\u2013and sported a CNC-machined aluminum alloy body. The radio also featured top-mounted controls ideal for field use, and a high-contrast LCD backlit screen with a spectrum display.<\/p>\n

Some of the initial photos of the prototype showed water droplets on the front faceplate indicating that the TX-500 would be water\/weather resistant\u2013\u2013certainly a first for the amateur radio market.<\/p>\n

After the initial hints dropped by lab599<\/a><\/strong>, the TX-500 developed somewhat of a cult following among field-portable radio operators (like yours truly) as well as those into radio preparedness. However, after this tantalizing flurry of initial images, there was a lull, and very little information was available about the rig. Then in late July\/early August 2020, we finally learned that the TX-500 would be sold in the US by Ham Radio Outlet<\/a>. HRO\u2019s product page posted a price of $789.95 with a projected availability date of mid-to-late September 2020.<\/p>\n

Thus I felt quite lucky when I learned that a loaner TX-500 was being sent to me for one week to evaluate and review. Those of you who know me and read my reviews know that I typically prefer to spend several weeks with a radio before I feel comfortable enough writing a review. In this case, that simply wasn\u2019t an option. I decided to push aside all of my other obligations and simply dive into this radio.<\/p>\n

The following review is based on using the TX-500 in the shack and in the field over the course of seven days.\u00a0 During this week, I managed to activate eight parks for the Parks on the Air (POTA)<\/a> program, exclusively with the TX-500. I\u2019ve taken the TX-500 to state parks, lakes, game lands, a National Forest, and a National Park. The TX-500 experienced full-on sunshine during a long operating session, and was even rained on once.<\/p>\n

I\u2019ve also made a number of QSOs with this radio from home, both via CW and phone. In total, I\u2019ve logged an average of 31 CW and SSB contacts with the TX-500 each day I\u2019ve had it.<\/p>\n

Initial impressions<\/h1>\n

\"\"<\/a><\/p>\n

The TX-500 looked so impressively machined and designed based on the initial photos and few videos published, I honestly feared it couldn\u2019t possibly measure up to the expectations built up about it. Would it be the rugged radio we\u2019d heard about? Could it travel? Could it hold up in the field, under variable conditions and in fickle weather?<\/p>\n

With the radio finally in hand, I noted the build quality and thought to myself, This rig might just do it.\u00a0<\/i><\/p>\n

\"\"<\/a><\/p>\n

The body of this radio is absolutely solid<\/i>.\u00a0 It\u2019s weighty without being heavy, and there are no loose parts\u2013\u2013no wobbly encoders, no wonky buttons, and relatively few seams or openings that might be subject to dust or water penetration. It\u2019s rugged, sturdy\u2013\u2013and, I must add\u2013\u2013beautifully engineered.<\/p>\n

\"\"<\/a><\/p>\n

The layout is simple: there\u2019s a backlit LCD screen on the left of the radio with four function buttons above and below it. These buttons control most of the functions and features you use while operating: CW adjustments, Receive and Transmit audio EQ, Noise Reduction, Noise Blanker, CW Memory keying, A\/B VFO control, and more.<\/p>\n

\"\"<\/a><\/p>\n

To the right of the display you find a set of buttons stacked vertically that include the power button, mode, band switching, and a menu button for making less common adjustments. The encoder is raised and feels silky-smooth to operate. There appears to be no brake control, but this is not a problem because this rig doesn\u2019t need it: it\u2019s well-balanced and feels of excellent quality. Indeed, tuning is adaptive and fluid; I\u2019ve been very pleased with the lab599 tuning.<\/p>\n

There are two knobs above the encoder which adjust the AF gain and RIT. Other buttons next to the encoder control things such as the tuning steps and speed, controls lock, and memory writing.<\/p>\n

\"\"<\/a>

The low-profile side panels do protect the TX-500 front faceplate on flat surfaces.<\/p><\/div>\n

You can tell the TX-500 was designed by an amateur radio operator because the radio is laid-out beautifully. All frequently used functions are easy to find and intuitive. There\u2019s no need to do a deep-dive into embedded menus to, say, change the RF gain control.<\/p>\n

There are a number of general coverage QRP transceivers on the market, so even just looking through the features and specs it\u2019s clear how it might stack up.<\/p>\n

This being said, the TX-500 does lack a few things you might find in other field portable QRP general coverage transceivers. We\u2019ll start with those.<\/p>\n

No (Built-In) Speaker<\/h2>\n

\"\"<\/a><\/p>\n

The TX-500 does not have a built-in speaker. With weather-resistance in mind, lab599 may have opted to leave the speaker out of the chassis, and instead include a speaker microphone combo with their basic package. The supplied speaker\/mic is of good quality and the audio can be made incredibly loud. And, although I\u2019m not a fan of speaker mics, I must admit this one has grown on me: in the field doing SSB, it\u2019s much easier to bring the speaker closer to your ears when trying to work a particularly weak station.<\/p>\n

But what about when operating CW\u2013\u2013? In that case, the speaker mic becomes inconvenient as you are forced to port out the audio via the speaker\/mic connector. It\u2019s worth noting here that the TX-500 package being sold by Ham Radio Outlet includes an audio breakout cable so you can attach your favorite headphones or boom\/mic set. My pre-production unit did not include this, so I had to use the speaker\/mic and its mono audio port.<\/p>\n

I, however, tend to operate with headphones in the field unless someone is helping me log stations. Headphones help me isolate myself from noises and distractions around me (like my dog straining on her leash, whining over her inability to chase squirrels). Headphones also improve my ability to detect and work weak signals.<\/p>\n

When I operate CW in the field, I tend to place the TX-500 on my backpack and attach the speaker mic to the top flap. It\u2019s worked out quite well.<\/p>\n

\"\"<\/a><\/p>\n

Audio from the speaker microphone is tinny, but actually well-tailored for voice and Morse Code. For shortwave radio listening, however, that\u2019s another story:\u00a0 you\u2019ll certainly want to connect a proper speaker.<\/p>\n

No ATU<\/h2>\n

The TX-500 does not include an internal automatic antenna tuner. For those used to operating an Elecraft field radio, the Xiegu G90, or the CommRadio CTX-10, for example, this might seem like a major omission.<\/p>\n

While it would be nice to have an internal ATU, I\u2019m quite happy to do without one, as all of my field antennas are resonant on the bands I operate. But as a point of comparison, it\u2019s nice when, say, my end-fed antenna isn\u2019t ideally deployed and can\u2019t get that 1:1 match on the 40 meter band; with my KX2, I can simply push the ATU button and the rig solves the match.<\/p>\n

\"\"<\/a><\/p>\n

I carry a simple Emtech ZM-2<\/strong> balanced-line manual antenna tuner, just for when an ATU is needed. But out of the eight field activations I\u2019ve done thus far with the TX-500, only once did I add the ZM-2 to the mix, and just to bring the match from a 2.3:1 to 1:1. If I wanted an external automatic antenna tuner, I\u2019d grab an Elecraft T1<\/strong><\/a>. It\u2019s a gem of an ATU.<\/p>\n

No internal rechargeable battery (yet!)<\/h2>\n

\"\"<\/a>The TX-500 transceiver doesn\u2019t have an internal rechargeable battery option like the CommRadio CTX-10 or Elecraft KX2. But like the new Icom IC-705 sports, lab599 is designing an attachable rechargeable battery pack that will fit the TX-500 beautifully. You can see the recessed battery connections on the back\/bottom of the TX-500.<\/p>\n

\"\"<\/a><\/p>\n

 <\/p>\n

As of this time, no availability date for this future option has been announced, but I can confirm it is indeed in the works.<\/p>\n

What makes the TX-500 unique<\/h1>\n

For some, the idea of a radio which lacks an internal speaker and ATU might lead the rapid decision to dismiss it outright. I would urge those folks to continue reading, however; the TX-500, due to some very unique features, has certainly carved out a market niche, and thus is worth the consideration.<\/p>\n

Rugged, weather-resistant body<\/h2>\n

\"\"<\/a><\/p>\n

As I mentioned above, the TX-500 has a solid aluminium-alloy body which gives it a distinctly solid feel. There are no gaps between chassis plates, and all of the buttons, knobs, as well as the encoder are sealed to prevent water penetration.<\/p>\n

The TX-500 design smacks of military-grade construction, but in truth is a blend of military specs and amateur radio functionality. For example, the chassis is, if anything, over-engineered for most amateur radio applications. If I owned the TX-500, I wouldn\u2019t hesitate to take it on extended hiking trips, even in dubious weather. Of course, that\u2019s not to say I\u2019d intentionally leave the rig out in heavy rain. But I wouldn\u2019t worry about a sudden rain shower ruining my radio. If this were a military radio, it would have fewer controls and likely be somewhat channelized. Instead, the TX-500 has the full set of controls, features, and filters you\u2019d expect in an amateur radio transceiver with a military-build quality.<\/p>\n

\"\"<\/a><\/p>\n

In short, it might appear to belong to rugged military kit, but it\u2019s very much designed for the demands of amateur radio operators.<\/p>\n

Although the TX-500 is incredibly solid, it\u2019s also lightweight. I weighed the radio with its speaker\/mic and power cable. The total weight was 1 pound, 7 ounces. One of my blog readers noted that such a lightweight radio would simply break in half if they hit it over their knee. My reply? No way.<\/i> In fact, I\u2019m willing to bet such an action could break your knee cap!\u00a0 Please don\u2019t try this, you\u2019ll surely regret it.<\/p>\n

Connectors<\/h2>\n

\"\"<\/a>One of the most frequent questions readers ask about the TX-500 is why its makers chose to include non-standard (to radio) GX12mm multi-pin aviation connectors for the rig\u2019s power port, CAT control, data, CW, and speaker\/mic…?<\/p>\n

The answer? In brief, it\u2019s water resistance.<\/i><\/p>\n

GX12mm connectors allow for a watertight connection and protect the radio very well from water intrusion. And while GX12 connectors aren\u2019t standard in the world of amateur radio, they are certainly standard in aviation, commercial, and military applications.\u00a0 These connectors are widely available online and there are even mom-and-pop ham radio retailers like W2ENY<\/strong><\/a> selling premade TX-500 cables and adapters on his\u00a0eBay store<\/strong><\/a>\u00a0and\u00a0website<\/strong><\/a>.<\/p>\n

Meanwhile, the TX-500 uses a standard BNC antenna connection for antennas, which I\u2019m very pleased to note.<\/p>\n

LCD screen with spectrum display<\/h2>\n

\"\"<\/a><\/p>\n

 <\/p>\n

Most of us now expect modern SDR-based transceivers to sport a full-color backlit\u2013\u2013and sometimes touch screen\u2013\u2013display. In the field, however, color TFT displays can be incredibly<\/i> difficult to read in full sunlight.<\/p>\n

Like the Elecraft K and KX series radios, lab599 opted for a more simple, higher contrast monochrome<\/i> backlit LCD display. This pleases me to no end, because I much prefer this type of display in a POTA or SOTA field radio just because it\u2019s so much easier to read in bright outdoor light. Also, I feel touch screens aren’t as well suited for hiking, camping, and heavy field use–they’re more vulnerable to being damaged.<\/p>\n

The TX-500 LCD is chock-full of information and very responsive. The spectrum display (no waterfall) is fluid and useful, as effective as any full-color display.<\/p>\n

Benchmark current drain<\/h2>\n

\"\"<\/a><\/p>\n

When operating on battery in the field, current drain in receive mode is a major factor. The more slowly you can sip from the battery while the radio is receiving, the longer play time you\u2019ll have. I like my general coverage field radios to consume less than 400 milliamps.<\/p>\n

My benchmark general coverage radio, the Elecraft KX2<\/a><\/strong>, consumes a mere 135-140 milliamps at moderate volume levels. I can operate for hours with a compact battery. The TX-500 consumes between 110-120 milliamps at a moderate volume level; yes, even a smidge better than the KX2. The company lab599 actually specs out this radio at 100 milliamps, and I\u2019m confident one could achieve it simply by using headphones.<\/p>\n

While there are transceivers like my MTR-3B<\/strong><\/a> which have even lower current drain, they\u2019re CW-only and lack general coverage reception, large displays, and the like. Thus, the TX-500 sets a benchmark for general-coverage full-featured portable transceivers in terms of drain.<\/p>\n

On the air<\/h1>\n

\"\"<\/a>In terms of operating the TX-500 in the field, I have very few complaints. The menu system is very easy to use and is intuitive. I never needed to reference the manual\u2013\u2013but if you do, the manual is one of the best I\u2019ve seen from a new transceiver manufacturer (click here to download he manual and other TX-500 files<\/a>).<\/p>\n

The buttons are easy to press. They have a tactile feel and proper response so you know you\u2019ve properly engaged a setting. The features and buttons are well spaced, too, and the thin-but-wide chassis actually provides generous surface area for the controls. One could easily operate the TX-500 with gloves on, should it be necessary in cold climates or winter conditions.<\/p>\n

\"\"<\/a><\/p>\n

As mentioned earlier, the TX-500 does not have an internal ATU option like the Elecraft KX2 or the Xiegu G90<\/a>. For some, this will be a huge negative against the TX-500. Good internal ATUs allow operators to use a much wider array of antennas in the field–including random wire antennas–and I\u2019ll admit that I\u2019ve gotten quite used to having one in my KX2 and KX3. But again, to get the most signal per watt, I use resonant antennas in the field these days, so very rarely need or employ an ATU.<\/p>\n

So how does the TX-500 play? In the following sections I\u2019ll address putting the TX-500 on the air as both a CW and SSB operator. Note that I did not have the opportunity to test the TX-500 on digital modes\u2013\u2013like PSK-31 and FT8\u2013\u2013as my pre-production model lacked the necessary cables, nor was building my own possible during the week of testing.<\/p>\n

CW<\/h2>\n

\"\"<\/a><\/p>\n

Of the (very few) videos that were produced prior to the TX-500\u2019s release, a couple of these were made by a CW operator in Russia. Unfortunately, I was able to glean little information from those videos. I was very eager to try the TX-500 in CW mode as this has become my preferred method of activating parks for POTA.<\/p>\n

When I received the TX-500, it did not come with the same cables that Ham Radio Outlet will include. It did, however, include the 5 pin connector for the CW port, so I simply soldered a cable and connected it to the terminals on the back of my Vibroplex single lever paddle.<\/p>\n

\"\"<\/a><\/p>\n

This way, I was able to avoid purchasing and attaching a three conductor ?\u201d female plug. (This intervention did mean that, in the field, my key would weigh more than the transceiver\u2013!)<\/p>\n

But the question every CW operator has asked me is \u201cDoes the TX-500 support full break-in QSK?<\/em>\u201d Full break-in QSK allows instantaneous transmit\/receive recovery time, so that even higher speed operators can hear between sent characters while operating. This means if another op wants to grab your attention while you\u2019re operating\u2013\u2013or, in the parlance, \u201cbreak in\u201d\u2013\u2013you\u2019ll hear them in the middle of sending a word.<\/p>\n

Unfortunately, the TX-500 does not<\/i> support full break-in QSK. Instead of being based on pin diodes (like the Elecraft KX series) the TX-500 uses a relay. This means that you\u2019ll hear a relay click each time the radio switches between transmit and receive.<\/p>\n

In the past, I\u2019ve reviewed transceivers in which the relay click was honestly quite loud, even annoyingly so. Fortunately, the TX-500 has such a solid and well-sealed body that I find the relay sound to be the least distracting of any relay-based transceiver I\u2019ve tested. You can<\/i> still hear it, but it\u2019s reasonably soft. So that you can hear what I mean, in this video<\/a>, you\u2019ll hear the relay clicking when I point the camera toward the rig.<\/p>\n