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Author Topic: My New Low Band Weapon...  (Read 476 times)
N7DM
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Posts: 671




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« on: August 06, 2004, 11:49:12 AM »

What with the lowering of Cycle conditions, the Eternal Challenge of a really decent low band antenna rears it's ugly head.  Here, the ground conductivity on this mountainside is so low that verticals rarely work...even IF there is not a bunch of tall evergreen trees [HF 'sponges'] in the path of desired propagation.   Yet, "one" must try.  This one is a 80 meter 'quarter wave' vertical ground plane. Four elevated [8 feet] resonant radials,  45 feet of 'vertical'...with two top loaders..to resonate the system at 3525.  Fed with  450 ohm twinlead of course.  It seems to 'work'... and, WILL absorb some RF on 160 as well.  

Look out Low Banders, The Phantom from Seven Land is coming!
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N7DM
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Posts: 671




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« Reply #1 on: August 08, 2004, 04:08:12 PM »

READY !   The top loaders turned out to be so short, it looks like a ten meter dipole up there.  30 + j0 on 3600 Kc, at the base...  Soldered on a chunk of twinlead and it matches perfectly at the rig.... as seen on a noise bridge preset at 50 + j0.   Yes... READY !
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N7DM
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Posts: 671




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« Reply #2 on: November 23, 2004, 03:42:27 PM »

I must, in all honesty, report that this antenna has turned out to be one of my True Lemons!  Not that it is the fault of the wire...or the design...but Nature. Yes, I live on the side of a mountain...solid ROCK a foot down, thru clay..terrible ground conductivity.  And, I have an Evergreen Tree Wall...around 100 foot tall, within a thousand feet, in all directions. The Prophet called it right...Verticals will NOT work under these conditions.  My Too-Low 80 meter Inverted Vee worked better, for Domestic Contesting.  For DX....I fear NOTHING will work here.  "Site"...verrrrry important. If you ever take a hankering for Low Band DXing, better buy acreage in fertile farm-land..with miles of un-obstructed area.  Try Nebrasks!   Or an Island.  Wake Island was good...
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N5YPJ
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Posts: 642




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« Reply #3 on: February 13, 2005, 06:28:18 PM »

Yessir!!!

Count yourself lucky having the trees for supports. I'm in a treeless canyon sitting on bedrock along the Rio Grande. Built a couple of vertical antennas 80 & 40 got BLAH performance at best.

Resorted to a 80 mtr loop at 35 ft that does better than expected on DX and great on 80 & 40 USCON qsos.

One silver lining - no one out here to gripe abt antennas or TVI hihi.

Ol Sol will be back one day.
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