Tag Archives: QRPguys DS-1

AX1, AX2, DS-1, HFJ-350M, MFJ-1899T: Compromised portable antenna strategies vary by location

Many thanks to Terry (N7TB) who sent the following question by email and has kindly agreed to allow me to share it here along with my response on QRPer:

Hi Thomas,

I cannot tell you how much I appreciate your POTA videos and all the suggestions you have made that I have adopted. I look forward to every activation you put on video. […]

[…]I have a question for you about using your AX1, and would really like your advice. I marvel at how quickly you can activate a park even with an AX1 antenna on 5 watts. I also have an AX1 antenna, counterpoise and KX2[…].

Anyway, I was out today activating K-0213, Maude Williamson State Park, about 20 minutes from my QTH in West Salem, OR. I operated 12W into a 33ft. EFHW antenna suspended vertically from a 31 ft. Jackite mast. All my activations are CW; I usually activate 20 meters.[…]

I was able to finally work 22 stations in an hour and a half, mostly in CA, UT, MT, and one in AZ. I did get a contact in KY, AZ NM, and MB, but it was a tough go for them to hear me. Most of my activations take me a bit over an hour to get 20 contacts.

As I thought about how much easier it seems that you are able to activate, I started to think about geography and population density differences between the East and West coasts. I used Google Earth and measured almost all points east of the Mississippi from Asheville and most were within 1200 miles. I would guess 2/3 of the US population live in this area. I drew the same range from my QTH and I get about half way into MT, barely into WY, most but not all UT, just touch the NW corner of AZ, and all of CA. In all but CA, I would guess the population total in this vast area is less than Illinois. That is my dilemma. I would love to be able to go out, setup my AX1 with my KX2 on even 10 watts, and make quick activations, but I would be surprised if I would get many contacts because the distances are so vast in the West and population density so low. I will actually try using the AX1 when the WX gets better and I can sit at a picnic table. So far, I have had little success with it, even deployed with the correct counterpoise. Do you have any thoughts on how to be successful with the AX1 from the West coast for POTA, or should I just concentrate on other antennas?

[…]Thanks again, Thomas, for the emails you have sent me with suggestions about equipment, and for all your great videos.

Very 73,



Hi, Terry,

First of all, thank you so much for the kind words. I really appreciate that!

Regarding your message:

Keep in mind that the day you were operating was a very strange day in terms of propagation. There were times when we were having radio blackouts (especially in the western half of the US) and there were times propagation was amazing, yet very unstable. We were hit by so many heavy CMEs this weekend–one seemingly on top of another.

I think you do have a valid point, though, about the geography–one I try to mention when talking about compromised antennas like the AX1.

QSO Map from my latest AX1 activation.

I realize that I enjoy a lot of success with the AX1 because of where I live. I guarantee that the bulk of the US ham radio population is within easy reach of my AX1 antenna, no matter what band.

For you? There are no hams to your west (within easy reach), extremely few to your north (save WA and BC), and the best ham density is to your south in California.

In your shoes, here’s how/when I’d try using the AX1 (keeping in mind I’ve never operated POTA in the western states):

First, I would focus on using 40 meters when the band is healthy and/or for early morning, late afternoon/evening sessions. That should snag contacts across WA, OR, and CA with the AX1. Might be a stretch for southern CA, but I think you could make that work. The only caveat is that flaring has been wiping out daytime 40 meters a lot lately. You might check band conditions in advance.

I would also consider spending time on 17 meters, and possibly 15 meters with your AX1. This might throw your signal across to the midwest, Ohio Valley, and beyond. 17 and 15 meters isn’t typically as productive as 20 meters (at least, for me) but I routinely log west coast stations on 17 meters with the AX1. 15 meters is also getting a lot of attention in the POTA spots!

A wire antenna is almost always a better option than the AX1 if you have the time and space to put it up, but the AX1 is just so darn convenient.


More suggestions?

The reason I asked Terry for permission to post his question and my reply here on the blog is because I suspect there are west-coasters (and those in similar geographic situations) who may be able to share some helpful strategies.

There are so many factors involved beyond what I mentioned in my reply. In fact, I imagine if the goal is to work parts further east, then adjusting the activation schedule for Central and Eastern time zones might also help (for example, not activating during dinner hours when I always see a bit of a lull in hunter activity).

If you have some experience, please feel free to comment!

Skip recommends the QRPguys DS-1 portable antenna kit!

Many thanks to Skip (K4EAK) who shares the following guest post:

The QRPguys DS-1 Portable Antenna Kit

by Skip (K4EAK)

There have been several videos and extended comments lately about the Elecraft AX1 and AX2 antennas, both of which function remarkably well for a small, highly compromised antenna.

For those interested in other, similar designs, especially those hams who find that building the equipment is half the fun, another option to consider is the QRPguys DS-1 antenna.

The DS-1 is similar in concept and design to the AX2. It consists of a base-loading coil, a 46.5-inch collapsible whip, and a plate to attach the antenna to a small tripod. One can also purchase an add-on 40-meter coil. The can be deployed in just a couple minutes and, when collapsed, the longest portion is only 6.5” long, easily fitting in the palm of one’s hand. QRPguys recommends a 16.5′ counterpoise; I use two such wires, usually spread out at a 180-degree angle. I’ve also used it with a clamp-on mount and a car window mount.

Building the antenna is simple and took me less than an hour. After installing a BNC connector into a brass plug and inserting the plug onto a length of PEX tubing, one simply runs the supplied 22AWG wire from inside the tubing, out and around making 22 turns, and then sealing it with a length of heat shrink tubing.

There are really only two aspects of assembly that are slightly more difficult. The first is that it’s necessary to drill and tap two holes for 4-40 screws, which obviously means that (1) one needs a 4-40 tap and (2) one needs to be careful tapping the threads to assure a clean cut. The second is that the heat shrink tubing, at least as supplied in my kit, was grossly oversized, which required some finesse in getting a final product that was at least reasonably aesthetic, to say nothing of accomplishing that without dry roasting my fingertips.

Field testing of the DS-1 shows that it works surprisingly well. The SWR is well below 2.0 across almost all of the 20-meter band and where it is higher than that (the upper end of the voice portion), the KX2 internal tuner can tune it easily. As one would expect, on 40 meters the antenna has a somewhat narrower range, although the KX2 tuner has handled it on all of the frequencies I’ve tested so far (all CW). And it appears to be efficient enough.

I have used it on numerous activations and consistently get to the requisite 10 contacts within 20 minutes or so after getting spotted. After that, the number of contacts depends on the time available, but for those occasions when I have only a 30-minute window for an activation, the antenna is a convenient and practical alternative.

I keep the antenna, the tabletop tripod, and the counterpoise wires in the water bottle pocket of my pack, ready for use whenever I have a few moments for a quick activation.

73 Skip K4EAK

Click here to check out the QRPguys DS-1 antenna