Discovery TX-500: Attempting a speedy POTA activation with a new rig and new antenna

While I love the opportunity to head outdoors and play radio, I also love shaking up my field kit and trying different combinations of radios, antennas, and other station accessories.

When using new-to-you gear, though, a best practice is to set everything up at home before you hit the field. This way, you can confirm that you have everything you need and you can also familiarize yourself with the gear prior to activating a park or summit.

Last Sunday (May 2, 2021), I threw caution to the wind. Well, sort of.  At the very last moment, I decided to squeeze in an activation en route to my sister’s home to do some brush-cutting and yard work.

The lab599 Discovery TX-500

Basically, I was chomping at the bit to take my lab599 Discovery TX-500 to field.

You see, in August 2020, I received an early pre-production TX-500 to evaluate for one week. In that seven day span, I activated seven parks with the TX-500 and enjoyed every minute of it. Because the loan period was limited, I packed a lot of TX-500 air time that week, then wrote this review for The Spectrum Monitor magazine.

As I mentioned in a previous post, if I would have had the opportunity to buy that loaner TX-500 last year, I would have. It wasn’t an option, though, as so few working models existed at the time. Now that I had a TX-500 in hand again, I couldn’t wait to hit the field with it.

Last Sunday, the weather was beautiful in western North Carolina, but clouds were moving in and we expected scattered showers in the latter part of the afternoon. The last thing I wanted to do was my sister’s yard work in the rain, so I needed to make the activation a speedy one.

But the TX-500 wasn’t the only piece of new gear. I also recently ordered and received a PackTenna 9:1 UNUN random wire antenna. I wanted to see how well it would perform, too, so I decided to pack my Elecraft T1 ATU and give it a go, too!

For the record: when you’re in a hurry, it’s not only a really bad idea to hit the field with a new radio and antenna, but to also throw the entire field kit together in 5 minutes before walking out the door.

On the drive to Lake James,  I mentally packed and re-packed the field kit trying to decide if I might have left out a crucial component (say, an adapter or cable). I also made the decision not to make a real-time, real-life video because 1.) this would surely  turn into a very clumsy deployment, 2.) I was pressed for time and didn’t want to set up the video, and 3.) I only had my iPhone with me to make the recording which would mean I would be giving up Internet and mobile phone access at the park which is important for spotting purposes.

So what did I do?

As I turned into the park entrance, I decided to make a recording of the entire activation from set up until the last logged contact.

Why would I do this to myself?

I reminded myself that the goal of my YouTube channel is simple: real-life, unedited examples of field radio operating. 

All of us, at some point, use new equipment in the field and we stumble through the process as we give the system a shake-out. So why not record it, right?

My iPhone battery had about 80% capacity. I knew if I tried to use the personal hotspot while recording the video–so that I could spot myself on the Microsoft Surface Go tablet–it would run down the battery in 20 minutes or so.  I immediately put my iPhone in airplane mode to preserve the battery.

Lake James State Park (K-2739)

I know this park quite well and assumed it would be busy on a beautiful Sunday afternoon. It was, in fact. I was confident I’d find a good operating spot, though, because they’ve a large picnic area and loads of tall trees to support wire antennas. And mid-afternoon, it was unlikely all of the picnic tables would be occupied.


I found a nice spot to set up and deployed the PackTenna in short order.

Since my iPhone was doing video duty, I didn’t take extra photos.

I hooked up the Elecraft T1 and attempted to find a match on 40 meters.  I thought I did find a match at first, but it turns out that the T1 was in Bypass mode. I didn’t have my reading glasses handy, so thought I saw a great match on the TX-500’s display. Turns out it was floating around 2:1. Still: not a bad match.

I worked five stations, then moved to the 30 meter band. It was then I finally realized the T1 was in bypass mode. I found my spectacles, read the front panel of the T1 and remedied that in short order (I can never remember the button press combo to toggle bypass mode!).

I tuned 30 meters and got a great match.

On 30 meters, I worked two stations.

I then moved up to 20 meters where I worked two more.

Then I moved back down to 40 meters where I topped off the activation with an additional three contacts for a total of 12 as I called QRT.

I’m very grateful to my buddy Scott (KN3A) who worked me on three bands all while he was activating a park in Pennsylvania! Thanks for those P2Ps, Scott!

In fact, I’m grateful Scott took the time to work me on multiple bands because it help bring my numbers above the 10 stations needed for a valid POTA activation.



After going QRT, I quickly packed up my gear (which was easy because there were so few parts), and started the 45 minute drive to my sister’s house. Fortunately, the rain held off the whole time I did the yard work!

I’m so happy to have a TX-500 back in the field radio arsenal.

Shortly after this activation, I officially purchased this loaner TX-500 unit from lab599. As I said in my “unboxing” video, there was no way I was sending this unit back. 🙂 Now I won’t feel bad if it gets dinged or scratched!

I’m sure the TX-500 will be in heavy rotation for a while. Please comment if you have any questions about this radio or the 9:1 UNUN PackTenna. I’d be happy to answer your questions!

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12 thoughts on “Discovery TX-500: Attempting a speedy POTA activation with a new rig and new antenna”

  1. Thanks for the report! I am glad you decided to video. I will go watch it shortly. You are correct about being clumsy in the field. I have no idea what I’m doing yet and watching other people experiencing issues as well gives me confidence to keep pushing.

  2. Hey Tom,
    Thanks for the awesome reviews about my favorite subject, operating QRP POTA.
    I am a CW op that enjoys activating Parks, Beaches and other special events.
    Based on my operating habits, I’d like your opinion of the IC705 vs the TX500. I am on the fence after selling my Kx3. I need a push, help.
    72and73 de Ke2yk

  3. Thomas,

    Great video of what happens when out in the field operating portable.
    I went to the Packtenna site and noted that all of their antennas are “sold out”. Don’t know if that is unusual or just temporary while they are waiting for parts from suppliers, which seems to be a common problem these days. A DIYer should be able to roll-their-own similar antenna.

    Henry – K4TMC

    1. Hi, Henry,

      You can definitely “roll your own.” These antennas are not complicated to build and they work amazingly well.

      With that said, I like supporting mom and pop ham radio manufacturers like PackTenna, so I’m willing to drop some money on products like this. I can say that the quality is simply excellent. I can tell this antenna will take a beating and keep performing.


  4. The CAT is coughing after every letter the memory is sending ? I hear it after every letter even when you send yourself, that’s really annoying. Are that the relays clicking ? Or is that due to the speaker/microphone ?

    Great video !

    1. That is more a factor of having the volume cranked up all the way for the video. The relays are not loud–about on par with the IC-705. The recovery time from a T/R relay switch, though, is 100 or 200 ms whereas with the IC-705 it’s full break-in QSK.

      I may try using a different speaker next time and experiment a bit.


  5. Since you had and used the excellent T1 tuner, rather than using a 9:1 impedance ratio unun why didn’t you just use a comparable length of antenna and let the tuner do the whole job? How long was the coax between the transceiver and the tuner? I wouldn’t be surprised if losses in the unun and coax exceeded additional losses in the T1 tuner working harder to match the antenna without unun and feedline. Cheaper that way, too!

    I can see using a much higher ratio unun with an antenna fed at a voltage maximum such as an EFHW, but I’ve never understood the logic of using a low ratio (such as 9:1) unun and a random length wire. With the voltage fed antenna, your ground sysem loss will be lower too.

    1. Hi, David,

      So being honest here, I don’t understand the logic behind low ratio UNUNs either, but you might check out this excellent antenna episode of the Ham Radio Workbench. George with PackTenna discusses a number of design choices and considerations:

      I think my RG-316 line is 10 feet long?

      I use the ATU to sort out the match a lot on my KX3, KX2, and KX1. It requires a counterpoise of course. I’m not sure I’ve ever tried that with the T1, but there’s no reason it wouldn’t work.


  6. Thomas,

    I don’t hear that “coughing” when you send CW yourself…strange… If it were the loudspeaker I should hear it then too I’d gather…
    It is however a nice piece of radio, being waterproof is a great plus.
    GL & 73

    1. I’m pretty sure it all had to do with have the volume absolutely maxed out on the TX-500 for that video.

      Thanks & 73!

  7. Hi Thomas, terrific video. Glad to see an “over-the-shoulder” view of a POTA activation for those of us who haven’t tried it yet. I also have the TX-500 and noticed a quirk when I long press the CW mode to go from normal CW to CW-R. The xcvr changes frequency instead of just flipping sidebands as the KX-3 does. Does yours do the same?
    Thanks and 73,
    David W3GZS

    1. Hi, David,

      You’re right. I haven’t needed to use CR-R yet. I just tried and it seems the frequency shifts 1.4 kHz. I wonder if that’s just RX or TX too? Hmmm…will check with lab599.


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