POTA QRP: Testing the new JNCRadio CS-818 ATU with my upgraded Yaesu FT-818ND

I love testing new stuff in the field and on Tuesday, May 2, 2023 I had a great opportunity to test a number of new items.

FT-818ND Upgrades

I mentioned in a previous post that I purchased a new Yaesu FT-818ND from DX Engineering on December 28, 2022. It smacked of an impulse purchase only in that I had not planned to purchase the radio that very day.

Thing is, Yaesu announced they were discontinuing the FT-818 and I always planned to purchase one to replace out one of my two FT-817NDs. I didn’t want to miss the opportunity to buy a new one under warranty, so I bit the bullet on short notice.

Within a few days of purchasing the FT-818ND, I also purchased another 500 kHz CW filter, a WINDCAMP 3000mAh LIPO battery and a WINDCAMP Anderson PowerPole Adapter.

I planned to make the FT-818ND my primary HF radio and use the other FT-817(s) for full duplex satellite work (and HF too, of course, especially since one is now in a TPA-817 pack frame).

I had all of the upgrades in hand by mid-February, but that Yaesu FT-818ND sat in its box under my radio bench until late April. I was so busy evaluating other gear and keeping up with my busy family life,  it had almost slipped my mind. Well, that and I received the incorrect narrow Collins filter from a seller on eBay; instead of sourcing a replacement, I decided to steal an original 500 Hz filter from one of my other radios while waiting on a replacement.

Those narrow Collins filters? They’ve become pure unobtainium over the past couple of months. At one point, eBay was chock full of them. No longer…

It had actually been a very long time since I pulled out a brand new (non-loaner) radio from the box. It’s funny because I remember opening my first FT-817 back in…what…2001? The box and packaging were identical some twenty one years later!

I unboxed then immediately opened the chassis of the FT-818ND to add the Collins filter, attach my Portable Zero side rails (stolen from my FT-817), add the Windcamp battery pack, and add the Windcamp Anderson PP adapter.

JNCRadio CS-818 ATU

Around the same time, Jesse, with Chelegance, also sent me his latest ATU: the CS-818 which is specifically designed to work with the FT-817 and FT-818 series radios. To be clear, Jesse sent the MC-818 at no cost to me to evaluate.

The CS-818 actually works with any radio, but it ships with the command cable for the FT-817/818 for full integration.

The CS-818 can handle up to 30 watts of power, so it’ll pair nicely with any QRP radio. If using it with a QRO radio, you’d have to be very careful not to push more than 30 watts.

NOTE: Due to the frame rate of my camera and the refresh rate of the OLED display, only a portion of the display shows up in my shots.

In truth, ATUs don’t get me terribly excited. I’m quite content with my Elecraft T1 and Emtech ZM-2; these two portable ATUs match anything and everything I use in the field.

That said, I like the design of the CS-818. I especially like the 1.3 inch OLED display which shows  SWR, Power, along with a battery level indicator. This, combined with my Yaesu FT-818ND’s voltage display, and I can see just how effectively the new Windcamp battery operates over time.

Zebulon Vance Birthplace (K-6856)

Setup was quite easy.

I had already charged the CS-818’s internal battery with a USB-C cable, so I only needed to connect my Chameleon MPAS 2.0 to the ATU, then connect the ATU to the FT-818 antenna port and, of course connect the FT-818 command cable.

Although my CS-818 didn’t ship with an instruction manual, it actually has one silk-screened on the ATU itself.

You can see how easy it was to operate in the activation video below. I’ve since learned (from Jesse at Hamvention) that the CS-818 has three different operating modes. In the field, I didn’t realize this, but discovered that the ATU would initiate a match when I keyed down in straight key mode.

Not surprisingly, it matched the MPAS 2.0 with ease.

Time to hop on the air!


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On The Air

I jumped on 20 meters and started calling CQ POTA. Within about seven minutes, I worked a total of six contacts.

The bands were in pretty rough shape (in fact, that’s been the status quo the past few months), so I decided to QSY to the 40 meter band and check for activity.

On 40 meters, I worked four more contacts in 11 minutes which gave me the full 10 contacts I needed to validate the park activation.

For kicks, I then moved back up to the 20 meter band and worked two more stations in two minutes for a grand total of 12 contacts in 32 minutes. I would have played radio a bit longer, but I simply ran out of time!


Here’s what this activation looked like when plotted out on a QSO Map.

Activation Video

Here’s my real-time, real-life video of the entire activation.  As with all of my videos, I don’t edit out any parts of the on-air activation time. In addition, I have monetization turned off on YouTube, although that doesn’t stop them from inserting ads before and after my videos.

Note that Patreon supporters can watch and even download this video 100% ad-free through Vimeo on my Patreon page:

Click here to view on YouTube.

I enjoyed using the CS-818 ATU and it seemed to work very well. Next, I’ll attempt to use it with more difficult matches. Look for that in upcoming field reports and videos!

And the new FT-818ND? I think I’m going to like powering it from the Wincamp battery pack. It’s nice having a battery pack that can not only deliver the full potential power output of the FT-818/817, but can also be charged in a couple of hours. The stock FT-818 battery pack takes ages to recharge, unfortunately.

I never tire of this radio!

Thank you!

Thank you for joining me on this activation!

I hope you enjoyed the field report and my activation video as much as I enjoyed creating them.

Of course, I’d also like to send a special thanks to those of you who have been supporting the site and channel through Patreon and the Coffee Fund. While certainly not a requirement as my content will always be free, I really appreciate the support.

As I mentioned before, the Patreon platform connected to Vimeo make it possible for me to share videos that are not only 100% ad-free, but also downloadable for offline viewing. The Vimeo account also serves as a third backup for my video files.

Thanks for spending part of your day with me! Have an amazing week ahead!

Cheers & 72,

Thomas (K4SWL)

2 thoughts on “POTA QRP: Testing the new JNCRadio CS-818 ATU with my upgraded Yaesu FT-818ND”

  1. I saw the tuner in action at Dayton and had a great chat with Jesse

    Its solid, well built, tunes fast and the display is crisp with a wealth of information.

    Here we are over 20 years later and the 817/818 is still in demand and accessories continue to be developed.

    Matching rails for it? Hi hi

  2. As so often happens, I read something here and end up spending money 🙂

    I’ve been on the fence about the Windcamp battery but having waited . . . and waited . . . and waited to charge the internal battery (only to be able to run it at half-power anyway!) I followed your link to the battery. Looks like the actual company does not have them in stock at the “official” store but the eBay link does appear to have actual Windcamp batteries available. I didn’t want to have a knockoff battery melt down in the radio!

    While we’re talking battery, I had the PowerPole adapter installed but continued to have power drain to the batteries, I’ll defer to those more knowledgeable here on the site but folks say that’s a condition of having a plug permanently installed? I’ve removed it for now to see if the drain issue persists with or without the adapter. I actually dismantled the Sotabeams adapter and kept the APP / plug pigtail and I’m also taking advantage of the cable adapters mentioned on The Tech Prepper website by Gaston allowing direct connection to a Bioenno barrel plug without the intermediate APP connection.

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