Bye Bye 10, Hello 15!

Yagis fall 2012 at SE0X

A new 15 meter mono band yagi has been installed at SE0X, it replaces the 10 meter 4 element yagi on top of the tower. The new antenna is an InnovAntennas 5 element OP-DES yagi on a 6.2 meter boom.

The reason for sacrificing the 10 meter mono band yagi is mainly the slow progress of solar cycle 24, the decision was made to put focus on 15 meter rather than 10 to optimize contest results.

A couple of considerations went in to the choice of the antenna, but most of all size and weight versus front to back ratio was the determination factors. I also wanted to try something new and the OP-DES (Opposing Phase Driven Element System) yagi from InnovAntennas was a very attractive choice with all this in mind.

The antenna arrived neatly packed in a 3 meter long carton tube with all hardware at precise quantities. Elements where clearly marked where needed and everything was tie-wrapped together in the box. The only part missing was a printed manual but that something I always use my iPad for anyway.

It took about a day to assemble the antenna and confirm all the measurements plus another day to bring down the tower and replace the old yagi with the new. All mounting hardware delivered with the antenna is made of stainless steel which is crucial as the QTH is by the sea. The galvanized clamps on the old 10 meter yagi where corroded and rusty after 10 years in the air and the nuts needed lubrication to come off.

Looking at the weather it was clear that the antenna would have to wait on the ground for one week, but the prognosis for the following Saturday looked promising. Six days later the prognosis was issued it remained sunny and Saturday morning came with sunshine and a no wind at all. After breakfast we tilted the tower and removed the 10 meter beam.

15m OP-DES SWREarly in the afternoon the new antenna was in place and I pulled out the antenna analyzer to confirm that the installation was OK. With the beam pointing upwards into the sky I had an almost perfect SWR curve with less that 1.2 over the entire band, rising sharply just above 21.500. After a little maintenance on the SteppIR the tower was raised again in the afternoon.

Raising the mast again was smooth and with the new antenna in the air I hooked up the antenna analyzer again and happily confirmed that the SWR was OK. No adjustments at all where made to achieve a perfect match, the length of the dipole was set according to the manual.

Before replacing the antennas I measured the pattern of the SteppIR and will do so again with the intention to see how the two antennas interact. I will post the finding to my blog once this has been done.

I could not have picked a better time for this project, the first week with the antenna has been a week with nice openings on 15 meter. The first 5 days operating the antenna I logged about 60 stations collecting 46 DXCC on all continents including KH2, KH6, 5N, 9M, XE, W6, W7, VU, V8, JA and more. I would probably have picked them all with the SteppIR, but it feels good to be able to confirm that the antenna works well.

So far the experience have been pleasant, the InnovAntennas 15 meter OP-DES yagi is well made out of quality material, and it works well. Next challenge for the antenna (and its support) is the upcoming contest season with the accompanying winter storms. I’ll post an update on the other side of the season.