Alpha-Delta DX-EE Antenna: Product Discussion

I am usually against buying wire antennas, especially dipoles. It seems kind of lazy to buy something that can be made quickly for very little money. There are exceptions, though. In my situation, I needed a multi band antenna for limited space and would work without a lot of tinkering and adjusting. The Alpha-Delta DX-EE 40-10 meter dipole fit the need.

The fan dipole.
The Alpha-Delta DX-EE is a “fan dipole” design. Although the coax is physically connected to all the legs at the same time, an RF signal will naturally seek out its own resonance. So if for example you transmit on 7.250 MHz, the signal will radiate out of the 40 meter section of a fan dipole and not be effected by the elements for the other bands.

Antenna applications.
The $140 Alpha-Delta DX-EE is 40 feet long and intended primarily for use in limited spaces. It will give acceptable performance when folded into an “L” or “V” configuration and is also suitable for attic installations. It is about as small an antenna you can get and still have most of the performance of a full size dipole. For those with limited space, it does not get any better than this without going to a true mobile/portable antenna or other unconventional design that will undoubtedly come with a lot of compromises. It covers 40-10 meters.

Due to its size, the Alpha-Delta DX-EE could itself conceivably be a “portable antenna”. While this sounds workable in theory, the solid copper wire is unwieldy and hard to work with and would break prematurely from constant bending. To adapt it for portable use you would need a way to roll up and store six elements, then deploy them when needed…and do it without turning all that wire into a jumbled up mess.

What’s in the package.
It’s just a dipole, so there isn’t much to the Alpha-Delta DX-EE: Six elements neatly rolled up, connected to a plastic feed block where the coax plugs in. Also included are plastic element spacers and extra wire to hold the spacers in place. They were also nice enough to include a generous supply of black antenna rope to hold it up. All the components are good quality and UV resistant. Alpha-Delta did not cut corners on the physical construction.

PHOTO COURTESY OF ALPHA-DELTA CORPORATION.

Assembly.
Slip the the elements through the spacers and secure them with a few inches of the extra (included) wire. Because the Alpha-Delta DX-EE is made of solid wire it will take a little effort to work out the kinks and keep the elements separated. It’s difficult to do this on a roof, so assemble the antenna on the ground as much as possible.

Tuning & Testing.
Tuning an antenna while still on the ground is very convenient, but the risk is that once installed aloft, the environmental characteristics will be different and adjustments that worked on the ground are no longer valid.

Simple antennas like dipoles should not be that picky, but it is possible. I prefer to test the antenna in its intended operating environment and make adjustments based on its performance in that realm, even if it means going through the hassle of having to pull the antenna down, tweak it a bit, raise it back up for testing, and repeating this process until it’s right. Maybe I’m being a bit picky myself? Use your own judgement on this one.

I sort of expect an antenna that has been on the market for years and is not a complicated design to begin with to work out-of-the-box with little or no fuss. That didn’t happen this time.

On 40 meters, the SWR was so out of whack that the antenna tuner on my FT-950 could not even get a fix on it. I put my MFJ antenna analyzer on it and discovered that the antenna had a 1.1 SWR…at 6 MHz!! The DX-EE was too long. It’s very important not to trim too much at a time. The DX-EE uses coils in the 40 meter section, so small changes in the overall length have a much more pronounced effect on the SWR than in a full size antenna without coils.

I trimmed only two inches off each end of the 40 meter section and that was enough to get the antenna to a 1.5 SWR across 40 meters. Surprisingly, the antenna tuner was not able to improve on this and in many cases it made the SWR much worse. This experience confirmed my long held suspicion that antenna tuners built into radios are not that good.

I had much better luck with the Alpha-Delta DX-EE on the other bands. 20 meters was a near-perfect 1.2 SWR across the entire range with no need to change anything on the antenna, and I got the same results on 15 meters. On 10 meters, I got a 1.2 SWR at the bottom of the band; at the top of the band the SWR went to 2.0, which is correctable with my FT-950’s antenna tuner.

On the air.
The real test of an antenna is how it performs on the air during an actual QSO, and the easiest way to do that is to check into a net. My personal favorite is NATA Net on 7.185 MHz beginning at 0000Z or 3.905 at 0400Z. I got a lot of great signal reports and was satisfied that the Alpha-Delta DX-EE was working as expected on 40. I also made some solid domestic USA DX contacts on 20.

That same evening I switched the antenna over to my FT-817 QRP rig and logged signal reports only slightly less than what I got with the full power FT-950. This is a testament to the value of low power operation. Radio amateurs would be doing themselves a huge favor by giving QRP a try; I have some ideas on how to get started in this Off Grid Ham article from January 2016.

Pros:
Simple, proven design.
40-10 meter coverage.
Small enough to fit in tight spaces.
Performs almost as good as a full size antenna.

Cons:
Solid wire is hard to control/work with.
Can be tricky to trim/adjust/tune.
May require an antenna tuner.

The bottom line.
The Alpha-Delta DX-EE is a very well made compromise antenna that does not compromise too much. The trimming/tuning process can be a bit tedious, but once done, the antenna delivers. The DX-EE is not stellar, but no compromise antenna is. It’s a great option for radio amateurs who do not have space for a full size antenna, but can do better than a portable/mobile version. The Alpha-Delta DX-EE is made of solid wire, which I don’t like, but I can’t really count that as a drawback; it’s just my personal preference.

Off Grid Ham score: 8.5/10

Alpha-Delta DX-EE, $135-$140 from online retailers.