Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: Prev 1 [2]   Go Down
  Print  
Author Topic: First attempt at a phased wire array antenna  (Read 1329 times)
WD4ELG
Member

Posts: 182




Ignore
« Reply #15 on: December 02, 2017, 05:03:10 PM »

I decided to start with a simple phasing approach, described in ON4UN's book (5th ed), where John lists out a close-spaced phased dipole (1/8 wave separation), fed 180 degrees out of phase, with 1/4 wave coax to one dipole and 3/4 wave coax to the other dipole.  This current forcing simplifies the task of getting the right currents to the dipoles without a complex phasing network.  The impedance at the junction won't be 50 ohms (I will need to measure it), but I can easily put a spare remote coupler at that point so the coax loss due to SWR between that junction and the shack is minimized.

First dipole is up at 32 feet and pruned for 3505 kHz.  Second dipole will go up early in the week. 

I decided to tinker with the first dipole and see what results I get, 9 PM Friday night local.  Called CQ with my FT817ND on 5 watts just for kicks.  Nobody answered.  Went to FT8 and worked a bunch of US stations with 1 watt.  Went back to CW and 5 watts, heard HA8RM calling CQ so I replied.  Got a 569 response to my "worthless low dipole and peanut power."  Now it makes me wonder if I should even continue with the phasing experiment!  Well, at least I know the one antenna must be doing OK and I am being heard with the first dipole.
Logged
WE6C
Member

Posts: 23




Ignore
« Reply #16 on: December 05, 2017, 09:57:47 AM »

An 8JK after W8JK is a better performer at low heights according to many.

I had one up for 75 at about 35-40' aimed at Europe and the South Pacific that did far better than a pair of 1/4 wave phased verticals hanging from tree branches when conditions were favorable.
It was far lower noise than the verticals or an inverted V at 90' yet signals were stronger in the favored directions and elevation angles.

A plus is multiband use with gain.

Then I moved here and had no simple way to support it.

Here two of many articles on the 8JK worth reading.

http://www.bvarc.org/Tech/CompactW8JKBeam-K5LJ.pdf

http://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/radcom/1990/09/page31c/index.html

Carl

Carl, Was your 8JK with elements side by side or one above the other?
Bob  WE6C
Logged
KM1H
Member

Posts: 2598




Ignore
« Reply #17 on: December 05, 2017, 12:04:29 PM »

In line as in a 2 el yagi or HB9CV, etc.
Logged
KZ4USA
Member

Posts: 298




Ignore
« Reply #18 on: December 05, 2017, 01:58:59 PM »

Inverted L might be better and wonder if you could phase two of them in line.
« Last Edit: December 05, 2017, 02:01:30 PM by KZ4USA » Logged
WD4ELG
Member

Posts: 182




Ignore
« Reply #19 on: December 05, 2017, 09:53:32 PM »

KZ4USA, I do have an inverted L for 160 that I use on 80 with a remote coupler.  It's about 1/2 wave on 80 so the ground losses are probably less than 160 due to higher impedance.  I will do some comparison tests when the phasing cables arrive for the dipole array.
Logged
WD4ELG
Member

Posts: 182




Ignore
« Reply #20 on: December 08, 2017, 05:33:26 PM »

Phasing cables ready for installation...but it is snowing and sleeting nasty out.  I know, "MAN UP."  It's 8:30 PM local, I cleaned the snow off the porch and deck (twice), walked the four dogs, did a bunch of chores around the house.  It can wait until tomorrow.  It's just a hobby.  It's just a hobby.

...
...

Let me check and see if it stopped snowing and sleeting yet...
Logged
W1VT
Member

Posts: 2525




Ignore
« Reply #21 on: December 08, 2017, 05:44:15 PM »

Just remember that if you drop any small hardware in the snow you won't be able to find it until the snow melts.
Logged
Pages: Prev 1 [2]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!