Sunday, 5 February 2017

Wind Is Not Our Friend

at least not if you're a minimalist QRP operator with wire antennas.  I have a couple dual band "Fan" style dipole antennas up and at this new QTH I have quickly discovered this winter that it is a very windy location being surrounded by farmer's fields.  A wire dipole in an inverted VEE set up is sensitive to position as far the angle of the legs goes.  Add to that the interaction between two sets of legs and the SWR can change continually as the wind blows.  When you operate QRP you tend to try and get away with smaller wire because you can since the power is so low.  The problem with that mindset is that when you are securing the wire legs you perhaps don't pull them as taught for fear of breaking them should the wind come up...especially if they are tied to a tree that will sway.   I made this mistake this past fall in setting my antennas for the winter.  One fan dipole for 20 and 40 was too flimsy and broke off on 2 different occasions at the center support.  A second antenna for 30 and 17 was constructed out of much more robust wire and a factory made 1:1 current balun.  Because of its robust construction I did not have the problem of breaking wires which is great but I did have the problem of the legs wrapping around each other in the wind.  This, of course, ruins the SWR and I had to go and fiddle with the legs.   Of course being winter it is not easy to tighten the ropes when one end goes down through the snow to a peg in the ground.  The solution I will employ this spring to avoid this problem is to offset the legs from being all in a straight line (north-south for example) to having one set of legs north-south and the second set of legs offset by 5 or 10 degrees.  This should eliminate them getting tangled up with each other.  I will replace my flimsy (read cheap) 20-40 fan dipole in the same fashion and hopefully have 4 bands I can use without interruption.

We are always in search of the best antennas or the simplest antennas.  I use tuned dipoles to avoid the bother of using a tuner which I chalk up to my minimalist ways.  I have one that I will use camping sometimes but it just seems like extra loss of QRP power when you can use a tuned antenna and avoid that problem.  I may be wrong there and feel free to set me straight.  I have also contemplated using ladder line to feed the dipoles as I have heard that it is a much better route to take due to low loss but then a balun comes into play and my coax run is quite short at less than 30' from my second floor window.  I'll still look into that as we are always trying to improve.  First order of business is to get that 20-40 antenna back up.  With the condx being so crappy lately I need all the options I can get.

That's all for now,
cheers es 72/73

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