amiga600.net blog

I have just installed a new multi band parallel wire dipole (for 80/40/20/15/10 Metres). I got an Alpha Delta DX-CC, which needed 82 feet, although a smaller 40ft version, the DX-EE without 80m and longer 100ft version, DX-LB Plus with 160m is available. I only just had enough real estate and the manual kept reiterating it would only be resonant in the clear, yet even with a good proportion of it only a few feet from my roof and some metal structures, it is resonant on all the advertised bands – around 2:1 SWR but as low as 1:1 and highs of 3:1, except for 80m (the internal ATU copes beautifully with any matching required).
 
The usable bandwidth of this antenna on 80m is less than the entire band, but the proportion it will cover is considerable – i.e. most of it. An internal ATU can more or less do the rest. I had some good contacts into Italy and Ireland last night and before work this morning on 40 Metres and 20 Metres. The entire 40m band is a flat 1:1 SWR.
 
As I wanted to keep the Sirio Boomerang for vertical HF operations, plus I have “permanently” erected my 10M fishing rod antenna (made by Pro Whip Antennas) at the home QTH, I have just bought an LDG AT-100 pro, which has 2 antenna inputs, so I don’t have to  worry about the limited capacity of the FT-2000′s internal tuner for the Sirio or the Pro Whip antennas.

A QRP operator is supposed to compensate lack of power by using efficient antennas. But what if efficient antennas are not practical? At my QTH, I cannot put huge antennas up due to lack of real estate. I tried a Diamond CP6 but sold it to a friend after the overwhelming size and venerability to the wind, especially when I was out of town, I was always worrying when it got a little windy.

So, I have thus far been using just a 25M end-fed longwire, but I was missing the local 10M club net, so I found an old Sirio Boomerang 27A and put it up. It worked a treat on 10 meters, but trying it on other bands with my LDG Z-817 Tuner seemed to be acceptable all the way down to 40M. It is especially “sweet” on 20M and 17M. I have made contacts into the USA, Cuba and all over Europe. I hope that others will try this remarkable antenna. I tried to go one better using a half wave CB antenna and it didn’t come close to the performance of this quarter wave – perhaps its some matching circuit in the Boomerang – whatever it is, its the perfect small HF vertical.