Tuesday, February 28, 2017

Deciding on a Multi Band Beam Antenna

The trouble is when you start building beam antennas and things go really well you end up wanting more!
Having successfully built the 17 meter Moxon I could go on to build another, like a twenty or a 15 meter version, but where the hell would I put them up. The problem is having had the taste of the db gain you get from such an antenna you wish you could have the same results on other bands. Which provides me with a dilemma?
I have a wonderful radio the Yaesu FTDX9000MP and it deserves the best antenna I can get, but I cannot put up a tower where I live because it’s an area of outstanding beauty and undoubtedly I would be told to remove it. I amazed how I’ve got away with the Cobweb and the Moxon without somebody complaining. So I’m stuck with my 30 odd foot scaffold pole which means I’m limited with weight and size of an antenna one of the reasons I built the Moxon, because it is very light.
I could probably get away with replacing the Moxon with a two element Yagi or something similar to cover the three bands, but again it would have to be light and so I’ve been looking at what’s about and have come across a few that might deal with my problem.
The old favourite, the Hexbeam, a good reasonable antenna and covers all the major bands including six. The Spiderbeam, another lightweight antenna which covers 20,15 and 10 meters or you can get one for the five bands. Lastly something like a Mosley mini-32-A antenna, a lightweight two element mini Yagi which covers the three bands 20,15 and 10. To be honest the Yagi would be my favourite because it looks simple to set up it's very light 6lbs and it’s less complicated that the Hex or Spider, I would cover the other bands 17 and 12 with other antennas.
A mini Mosley beam like the 32-A might work for me!
The other issue for me is whether to build or buy? At the moment I have little time available to me to build so I would most likely have to go down the purchase route and my limit would have to be around £400. The entire antennas I’ve mentioned are roughly around that price although the Spiderbeam is a little more expensive at 400 odd Euros. Interestingly the Yagi M-32-A comes out the cheapest but literally by about £10 over the Hex!
We'll just have to wait and see, whatever the outcome it's a hobby at the end of the day, so it's quite a nice dilemma to have!

Sunday, February 12, 2017

An Un-Expected Pleasure on Saturday Morning

Early Saturday morning, first thing I normally do is switch the radio on. It's typical that you build a new antenna and then the band goes quiet on you! In this case it's the 17 meter Moxon, a few European stations can be heard but that's it.

So I decided to take a look round the lower bands to hear what's going on. 80 meters is the usual local traffic with what I jokingly call the amateurs complaining of pains and politics band! Which can be very entertaining, but today I wasn't in the mood. 

Switching up to 40 meters it was mostly European stuff and moving on to 30 I get something similar, but round 10,124 I hear a feint station calling a CQ which takes my interest, cos it's got that echoey sound of distance and no one has picked up on it yet.

A bit of QSB but I can still just hear it calling, I zero in and get the headphones on,  sure enough there it goes again and still nobody has picked it up, wait a sec that's a ZL station ZL3XDJ. In to action I go, filters on, zero the beat, quick ATU check and put the power up and away I go.

M0AUW K pause, back he comes, it's Brian whom I heard a few days back with very nice CW, It does make a difference when you hear good CW! you appreciate the spaces and clarity especially when its DX stuff and especially when you've had a stroke and your brain is just not quite there!

He gave me a 579 and I was so happy, I had a permanent grin on my face all day!

Friday, February 3, 2017

The W5GI Mystery Antenna

One of the first antennas I built was the W5GI mystery antenna, it makes an excellent antenna as a starter project when first entering the hobby.

The Mystery antenna covers 80 to 6 meters with low feed point impedance and will work with most radios, with or without an antenna tuner. It is approximately 100 feet long, can handle the legal limit, and is easy and inexpensive to build. It’s similar to a G5RV but a much better performer especially on 20 meters.

The W5GI Mystery antenna, erected at various heights and configurations, is currently being used by thousands of amateurs throughout the world. Feedback from users indicates that the antenna has met or exceeded all performance criteria. The “mystery” part of the antenna comes from the fact that it is difficult, if not impossible, to model and explain why the antenna works as well as it does. The antenna is especially well suited to hams who are unable to erect towers and rotating arrays. All that’s needed is two vertical supports (trees work well) about 130 feet apart to permit installation of wire antennas at about 25 feet above ground.