KC8QMU
03-04-2004, 10:10 AM
I was just wondering how many of you have/are running one of these, under what conditions and what your opinion is of it. Thanks! http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif
I have had a DX-B sloper for several years. Got it on eBay for $25.00 new in the package. I had been using half slopers for each band since the early 80s and thought that I could replace 4 wires with one wire. Actually I did! There are some things that you should know about using any half sloper including the Alpha Delta.
1. Regardless of what Alpha Delta claims, the DX-B or any half sloper is most effective when it is mounted on a tower at the 30 - 60 foot level, (38ft works well for me) and the tower has a large tribander or VHF arrays on it. This gives the system some top loading.
2. Mounting it on a pole with a lead to ground is not going to get it done. I have tried this on occasion and the performance is degraded considerably. Same as mounting it on a tree or on the side of a house. You will be able to make contacts, but a low dipole or loop will almost always out perform a half sloper set up this way.
3. These antennas are primarily vertical radiators and do a decent job on DX at 40 - 75 - and 160 meters. However, for close in local work, you would get better signal reports with a low dipole.
4. On the DX-B 3/1 SWR points are about 12 khz either side of resonance because it is shortend for that band. My full quarter wave 160 half sloper had about 75% more bandwidth then the DX-B. My experience with any 75 meter sloper I have tried is that the SWR is almost never lower that 3/1 and is ofter 5/1.
In my installation at tuner is needed for 75 meter operation and for moving around on the 160 meter band.... but the antenna performs very well on these bands, somewhat better than my Butternut HF2V with a modest radial system which was also a good antenna when I had it up. On 40 and 30 meters, there is much wider bandwidth.
5. The addition of a radial set tied to the tower seems to make a positive difference. I did some extensive testing over the air using radials and without and most stations report that there was more punch to the signal when using a radial system, although it did not always show up on the S-meter. Performance without a radial system is very good however.
If these antennas are set up correctly, either the Alpha Delta or a simple quarter wave wire set up as a half sloper will work fine. If not set up properly, you will be dissapointed.
73
George
K3UD