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[TowerTalk] Shortened Dipole on 160M

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Subject: [TowerTalk] Shortened Dipole on 160M
From: franknorton@home.com (Frank Norton KB8XU)
Date: Wed, 19 Sep 2001 10:37:19 -0400
Hello all,

I hope my editing keeps this post within range of concentration yet does 
not remove vital info.  My comments are noted in caps---BECAUSE NO OTHER 
FORMATTING IS POSSIBLE.  SORRY, I PROMISE I AM NOT YELLING.

PART ONE FROM MIKE VE9AA:
At 04:29 AM 9/19/2001 -0400, you wrote:

><< In a message dated 9/18/01 6:02:31 PM Pacific Daylight Time,
>ve9aa@nbnet.nb.ca writes:<<
>   Frank, et al
>   Guess I missed the original post and the subsequent ones, but FWIW, I've
>   tried hundreds of antennas over the years
>   for all bands 70cm-160m, many of them on 160m.
>   Specifcally for 160m,  <SNIP-SNIP>
>   5/16th-WL Inverted L wire with series cap--VARIATION ON THE 5/8TH 
> LAMBDA THEME?  SOUNDS VERY INTERESTING.
>        The last antenna BAR none kicked the others butts BIG TIME.
>    I strung 170' of insulated #12AWG as an inverted L  over some tall Poplar
>   trees in my yard, with a large series air variable ~800pF and it really
>   works well. I have about 30-some full length 1/4wl radials)  IT REALLY 
> HELPS TO HAVE THE RECIPE INCLUDED LIKE THIS, THANK YOU.
>   It ain't no 4-square but it is amazing. <SNIP AGAIN>
>   I almost always had 2 or 3 antennas on the go at any one time so always did
>   the "A-B" comparison thing.
>    I can assure you, the 5/16th inv-L cracked the pileups <SNIP AGAIN>
>   this antenna REALLY works.
>   Save yourself some time (AKA blood/sweat/tears) and install an inverted 
> L.  YES, I AGREE THE INVERTED L IS LISTED RIGHT AT THE TOP OF MY SUMMARY 
> I POSTED OF TRANSMIT ANTENNAS==JUST AFTER LOADING THE TOWER.
>    1000' unterminated BEV for RX @ times  THIS SOUNDS LIKE A DREAM COME 
> TRUE, I WISH I HAD THE AREA.  WORKING WITH A DOUBLE CITY LOT/HOUSE ON THE 
> FRONT CORNER AND ONE SIDE.  POWER LINES ON REAR AND ONE SIDE OF HOUSE 
> (RIGHT ON PROPERTY LINE OF COURSE : 0( .
>   FWIW
>    Mike VE9AA  THANKS MIKE, VERY HELPFUL!
>   <SNIP-SNIP-END OF PT 1>

PART 2 K7GCO:
>Mike: This is a very good report.  The L has been a very good antenna even
>back in the 30's.  I started a trend of making it longer than a 1/4 wave and
>adding a variable BC variable in series to tune out the XL from being too
>long.  It also raises the Rr closer to 50 ohms or even above for 70 ohms
>coax. A COUPLE OF FOLKS RECOMMENDED THIS, SOUNDS LIKE A GOOD POINT BUT== 
><SNIP>  The vacuum variable is nice but is a problem to adjust from the 
>shack.  The 1000 pf BC variable does its thing in less than 180 degress 
>across the whole 160 m band.  <SNIP AGAIN> The idea is to get the best 
>average SWR curve from 3.5-4 MHz or 1.8-2 MHz or the range of frequency 
>you will use.  This procedures should be obvious but there are still some 
>that can't grasp the idea. ---HERE I REVEAL MY IGNORANCE ON ONE OF MANY 
>SUBJECTS:  THE DEFINITION OF A BC VARIABLE AND ITS FUNCTION.  I HOPE IT IS 
>CONTROLLED FROM THE SHACK, IF SO WHERE WOULD I GET ONE ON THE WEB?  (I 
>CAN'T LEAVE THE HOUSE TO GO SHOPPING AT HAMFESTS ETC., I HAVE FRIENDS AND 
>FAMILY WHO DO ALL OF THE CLIMBING, HANGING, AND SHOPPING.  THANK GOD FOR 
>THEM.)  UPS STOPS HERE BY INSTINCT NOW, HI HI!
>
>I've had great success with the horizontal quad loop for local and a fair
>ways out with no skip zone like a vertical.  I've worked some 4000 mile DX on
>75 SSB also.  A quad loop say .15 WL high uses the ground as a reflector
>giving it a "kick start" up up up and away not even passing over ground
>before it hits the receiving antenna.  I call it the "Slam Dunk Antenna."  It
>has a very efficient path.
>
>I use a couple of ways to load a 80M quad loop 20' high on 160 (or a 40M loop
>on 80M) with a way to get low SWR (50 ohms) over the entire 160 or 80M band
>using 600 ohm open wire line with virtually no feedline loss. <SNIP 
>AGAIN>  High
>angle does far more than most are aware of throughout the entire 11 year
>cycle and over 24 hours.  I consider the horizontal loop a must for every
>ham.---LOOPS IN ALL FORMS AND PLANES SOUND WONDERFUL.  TROUBLE HERE IS 
>THAT THE CITY PLANTED ALL DWARF TREES!  I CAN'T GET AWAY WITH 3 TOWERS, 
>EVEN IF I CUD AFFORD 'EM.  I MIGHT GET AWAY WITH MASTS--WHICH IS WHY I 
>POSTED THE QUESTION ABOUT ANYONES EXPERIENCE WITH FIBERGLASS MASTS.  THOSE 
>SOLD BY GOOD OLD RADIO SHACK ARE A 3 SECTION TELESCOPING ARRANGEMENT THAT 
>EXTENDS TO ABOUT 30 FEET.  I HAVE NO IDEA HOW RIGID THEY ARE, BUT THEY 
>WOULD BE A GREAT "RADIO TRANSPARENT" WAY OF SUPPORTING SOME OF THESE LONG 
>160M ANTENNA WIRES.  ESPECIALLY IF I CUD EXTEND THEM BY ADDING A METALLIC 
>BASE OF ANOTHER 10 FEET OR SO.  OR, HOW ABOUT OTHER FIBERGLASS SUPPORTS, 
>ANYONE KNOW OF ANY?  SURE WUD HELP WITH THIS PROJECT!
>
>Your having 2 to 3 different antennas up for a A/B/C test is a great idea
>that few do.  I've worn out a couple coax switches over the 
>years.  k7gco  THANKS MIKE, VERY HELPFUL IDEAS FOR HOW TO WORK LOW BAND DX 
>FROM A CITY LOT (OR 2).

BY THE WAY, I HEARD FROM SPI-RO (THE ONES WHO MADE THE TRAPS IN THE 80/160 
DIPOLE.  THEY RATE THEM AT 600W AND WUD NOT CLARIFY WHETHER THAT WAS PEP OR 
CONTINUOUS, OR THE RATED TIME.  THEY DID SAY THEY DO NOT BUILD ANYTHING 
CUSTOM (LIKE HEAVIER TRAPS).  NO CALL SIGN FROM THE PERSON WHO ANSWERED MY 
QUERIES TO THE COMPANY.  DOES ANYONE KNOW HOW THESE TRAPS ARE RATED, OR HOW 
I CUD TELL, JUST FOR GRINS? I HAVE THEM SITTING HERE AND WUD LIKE TO HAVE 
SOME KNOWLEDGE OF THEIR TRUE POWER HANDLING ABILITY.

still me: Thanks again to everyone who posted or emailed me about working 
160M DX from the city.  I've got quite a file of TopBand antenna 
pointers.  Some of the stories from people who have been at this for 50 
years or so were especially interesting!

73 de Frank KB8XU  PS isn't it nice not to be looking at all those capital 
letters?  I wonder why that is from a psychological perspective.


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