The ATX-1080 is a small multi band vertical antenna covering 80 – 6 meters, including the WARC bands. It is very similar to the MP-1, a major difference being that the coil is placed at the bottom. Also, the MP-1 has a continuous tuning on the coil while the ATX-1080 has fixed taps for the connections. I bought the antenna at the German Wimo who even supplies some extra documentation along with the original paper.
|PL and BNC
The ATX-1080 is a simple base loaded telescopic whip antenna. The coil has five tap positions, which combined with variable telescopic length can resonnate on the ham bands between 80 and 4 meters. The ATX-1080 should also make out a reasonable 5/8 lambda antenna on 2 meters.
Like any other HF vertical antenna, the ATX-1080 needs a ground plane. This can be obtained by attaching a wire to the ground connector of the radio or of the antenna tuner you are using. According to the manual, this wire should be less than 1/4 lambda. Wimo, the company where I bought the antenna, complements the manual by providing some good start values for the radial lengths for each band. There is more on this on the tuning page.
The antenna has been specially desigen for transceivers like the FT-817 and the Mk 2 version comes with both BNC plug for the front connector of the FT-817 and a PL90°-plug, which can be used for the rear connector.
On the Air
The antenna is almost plug and play. Using the table in the manual connect two taps and set the telescope length to the start value. Hereafter the SWR can be fine tuned by adjusting the telescope. On some bands the start values are very good while on others I have come to rather different telescope lengths.
On the receiver side this antenna performs very well. I have tried it on 40, 30 and 20 meters where I could hear the usual traffic, including some DX stations once in a while. It does indeed make a huge difference, whether there is a radial attached to the rig or not. When I attach the radial to the tuner chasis, the signals go from S0 to S9! It also makes a big difference whether the radial is deployed to its full length or just in a bunch. The former is the prefered way, of course. The band-width of the antenna seems to be quite adequate as well; I have almost flat SWR across the CW sections.
If I take into consideration the small size, weight, performance and relatively low price of the antenna, there is no doubt that it has been a good investment. With this antenna it is very easy to set off for a quick DX-pedition no matter whether you are driving a car, riding a bicycle or are just a simple pedestrian. Well, I guess if you walk around with this antenna deployed and a 5 meters long radial dangling behind, you are not just a simple pedestrian…
There is only one bad issue with the antenna that I have received: The tightening tips on the PL plug are rather strangely aligned. I have plugged the antenna into both the FT-817, IC-765 and FT-301; in none of them could it fit in so that it could stand in a perfect vertical position. If I want to tighten it I have to tilt the antenna something like 5 degrees. Fortunately, I can rotate the socket of my antenna tuner, so that I can have the antenna in vertical position when plugged in there, but I surely will not always bring that big 300W tuner with me.