[TowerTalk] Open wire line convert

[K7GCO@aol.com]

  In a message dated 9/17/00 5:20:48 PM Pacific Daylight Time, K7GCO 
writes:<<   
     << Tom,
        Don't forget to mention that all of W1EVT's open wire runs are 
several 
        1,000 feet long from the culvert under the road to the top of a high 
hill 
        quite a way away and he mostly operates 80 and some 40 Meters. It is 
also 
        was a business venture and coax would have been out of the question 
for 16 
        runs!
        
        At 06:48 AM 9/14/00 -0600, n4kg@juno.com wrote:
        
        >Just because open wire line isn't a viable solution for YOU
        >doesn't mean that it isn't a viable solution for OTHERS
        >and should be banned from existence as you seem to argue.
        
        I believe your claim about Clem's his 5BDXCC is bogus. I believe W4DR 
holds 
        that distinction and I doubt that Clem would have ever claimed he was 
        working on it no less apply for same!  The Clem I know is just a DXer 
and 
        not an award chaser or competitor of that sort. He enjoys working 
JA's at 
        sunrise and on the winter sunset long path around Christmas.
        
        >W1EVT, winner of the first 5BDXCC, uses 4 wire open wire
        >lines to run under the road and up the hill to his 19 towers
        >with 3 sets of stacked wire arrays (two half waves in phase
        >stacked every half wavelength) for every band.
        
        BTW, I get a kick out of K7GCO's claim about using Teflon insulators 
from 
        the 30's (the decade when he was born!). As I recall, the material we 
now 
        call Teflon (RTM) or PTFE was invented by Dupont in the 1950s!
        
        I have also used open wire line over the years but particularly on my 
432 
        extended expanded collinear EME array. You can see it in full in my 
article 
        in QST, December 1974, page 38, "VHF Antenna Arrays for High 
        Performance", by W6FZJ/1. I later abandoned open wire line because it
        had radiation loss (even at 0.75" spacing!) and every time the 
humidity
        went up a few points or an insect walked across the 
"Teflon"insulators, 
        the VSWR went through the sky!
        
        >Several of my dipoles are fed with ladderline and used
        >successfully on multiple bands.  I have no problem
        >with running the ladderline across my yard suspended
        >from tree limbs and guy wires. 
        73, 
        Joe, W1JR
         >>
       Correction!  To my knowledge I have never stated other than in a 
typing mistake I used Teflon spacers in the 30's.  Can you show me where I 
said that and if not then correct the error?  I have enough trouble with 
others intentionally changing what I say and making a Joke out of it.  I used 
the Johnson Porcelain spacers, I still have them and just found a bunch more 
in the flea market.  Wooden dowels boiled in wax is not a good idea although 
very cheap.  On 20M with 600 W I could hear a cracking noise.  Perhaps if the 
cut spacers were dried in an oven and then boiled they wouldn't crackle.  
They will eventually fail so forget wood boiled in wax (outside) at least 
from cheap wooden dowels.  Hard wood dowels would a bit better.  As I have 
advised before--bite the bullet and buy the porcelain ones in the flea market 
or make them from Delrin.  (Would you believe if you're living in the past as 
some seem to be (even me) you can still get Teflon after the 50's.)  For 
those who can't time travel and don't know where to get Teflon or Delrin, 
look under Plastics in the Yellow pages.  I'd use at least #12 enameled wire 
or larger.  The VF will be around .98 for spacers about every 3' .  If the 
wire is insulated it will be less and you will need to grid dip it by 
shorting both ends--and trimming.  Trimming seems like a big problem for some 
but is really very elementary.  Having it resonant at 3.562 MHz as a half 
wave (135.4'), it will be a 1/2 wave multiple at 7.125, 10,.687, 14.25, 
17.812, 21.375, 24.937 & 28.5 MHz.  It will grid dip at all these frequencies 
real close if it's supported at least 5' off the ground tied with ropes.  
It's a 1/4 wave on 1.781 MHz.  These lengths reduces reactive problems.  For 
specific bands you can grid dip to fit or I've used a switch in the shack to 
add or subtract line.  If more line is needed double the length (270.7') (or 
triple) and all the resonant frequencies hold inaddition to being a 1/2 wave 
on 1.781 MHz.  203' is a 3/4 wave on 3.562 MHz but still 1/2 wave multiples 
on all the higher frequencies--40M and up.  All this insures that the antenna 
Z will be repeated at the END of the feedline.  That is the critical area of 
matching--not at the antenna as is usually taught.
       
       Inaddition to tuning techniques, tuners and no-tuner techniques, I 
will be presenting this data in a very detailed article for one of the mags.  
Open wire line info creates hostility here for some strange totally closed 
minded reasons for some. 
         
       I have consistently recommended ONLY open wire line of .98 VF but the 
poo pooer's insist on pointing out that the 450 ladder line with .89 VF has 
higher loss which it does and in particular when wet.  Waxing prevents water 
absorption of the dielectric and it cures the extra loss problem when wet--so 
there.  Several have been giving open wire low loss success stories.  One 
installation on 80M using a vertical of about 1000' with transformers had a 
measured loss of -.3dB (eat your heart out coax users), will last a long 
time, it's easy to repair and a very very low cost installation.  A signal 
savings of 1-3 or more dB on the LF's is very worth while.  Let me put it 
this way.  Say you ran legal power and saved 3 dB using open wire line over 
coax.  It would require doubling the power which would also be illegal.  To 
purchase a linear of twice the power could cost more than 3 dB of $--maybe 6 
dB of $.  The coax signal loss is lost on receive with no way to recover it.  
Further a tuner will assure maximum power into the feedline--over the whole 
band where typical SWR curves tend to reduce the power output form the 50 ohm 
finals on the band edges--not with link coupling to the final tank circuit.  
Put that in your "efficiency loss pipe" and smoke it--but don't inhale.  When 
the final sees other than 1:1 SWR, the heat dissipated from it 
increases--even more.  Eventually the maximum power ham will for certain 
applications come around to open wire line--when $$$ is considered.  
       
       Let me put it another way.  With all the thousands of feet of coax I 
have purchased over 60 years I have no figure.  I recently learned about 
compound interest buying a $110,000 house and ham property.  I didn't use 
that formula in Engineering Math.  Here is a startling example that I haven't 
recovered from as yet.  Since 1977 I purchased front row tickets on the dug 
out for the Seattle Mariners.  I've spend over $110,000--the value of my new 
house and property.  I asked my broker for the formula for what that would 
have grown into over 23 years at 10%.  It is over $500,000.  Had I purchased 
cheaper seats, I could buy lot of ham gear--perhaps I could afford some new 
coax.  Had you made your own open wire line over your ham carrier, the 
savings invested would be a big fat figure.  It absolutely staggers me what 
I'd have (and all hobbyists) piled away had I not got into ham radio, 
photography, guns and some other areas just for hobbies starting in the 30's 
and then just invested it.  Think "retirement nest egg" when you need 
transmission line.  Remember when you are retired you will have 10 more hours 
a day to spend money.  Today most retirees thinking they will really enjoy 
their hobbies find that they are Involuntarily, Financially Bankrupted out of 
their Hobbies.  Outrageous Medical bills have ruined more hobbies than any 
other factor.  The cost of rigs and antennas are one of the best buys on the 
market--if you have any money left over.  Fortunately I hoarded lots of 
stuff.  Actually I didn't hoard it--I got it to keep those damn hoarders from 
getting it.  Where did I go wrong?
       
 Remember K7GCO's Law of Retirement: What you did professionally or how much 
money you made and kept at retirement is totally irrelevant.  The only thing 
of any importance is how mobile you are (can climb a tower), work Ham Radio 
and still get it up.  If you can't do these things, you have totally failed 
to properly prepare for retirement.  My anti-vitamin doctor of my age died 
about 10 years ago--a victim of his own profession.  They die at an averages 
of 58 and Dentists even sooner.  The reason would surprise you and it's being 
covered up.  K7GCO. 
       
  

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