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Author Topic: vertical antenna for 160 ,80 &40 mtrs.  (Read 3307 times)
KB2HUK
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Posts: 164




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« on: July 23, 2010, 11:15:12 AM »

Hello All !  I am looking to add a vertical antenna to round out my antenna farm .  The 3 most bands I am interested in are 160,80 & 40 meters .  who makes the best Vertical antenna for these bands .  I am also looking for a inverted V antenna to hang from the top of my 60 foot tower for the same bands .  Any suggestions would be greatly appreciated.  thanks John Kb2huk
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N6AJR
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« Reply #1 on: July 23, 2010, 11:29:28 AM »

For the verticle I reccommend a gap voyager This is a 46 foot tall antenna that will work on 20, but works well on 40/80/160 meters.  Mine has been up for 5 years or so, and no problems and I bought it used.  it is very floppy and bendy going up and need a minimum of 2 sets of rope guys, but it works .

 another 160 antenna can be homebrewed  . loom at K6MM.com for his home brew 160 vert. 

as far as  the dipole , I highly reccommend  the Fan Dipole.....

The key to understanding a "Fan Dipole" is in the lazy habits of the electron.
 
if you have a  coax ( or twinlead) feed a  dipole with multiple  paths for the current to flow in,  the  path  closest to the  resonant freq of the signal will find the electrons  folwing the easiest there. and example:
 
you have a coax fee to a pair of dipoles , one with 33 feet on each side and one wire with 66 feet on each side.both connected to the end of the coax, one side to the center conductor, one side to the shield.  Lets send a radio frequency of about 7.100 MHZ  up the pipe. the 33 foot on each side dipole will show an impeadance of somewhere between 30 and 75 ohms.  most of the current will flow in this wire.  The other wire pair will have an impeadance of from several hundred to several thousand ohms. only a small portion of the current will flow in the other pair.
 
so you can run the 80 meter dipole north and south and  you can either hang the 40 meter dipole below it or run that one east and west.  different pattern but same antenna.
 
on the several different designs shown in the example, the path is simply down the diagonal and them off on the wire that comes closest to being the right  impedance.  it couls be divided between several if they are similar in length like a log periodic. Hope this helps
 
 and here is several other ideas...
 

Bye the way, none of this is mine, Its just stuff I pulled from here and there. thanks to all the folks with the great sites. this is My take on the multi-band, single feed wire dipole ( but fan dipole is easier to type.  a true fan dipole is also called similar to a cage dipole and has 3 or 4 wires of different lengths on the same band , like a 64 foot , 66 foot and 68 foot  double leg wires on the same feed to give wider bandwidth, but bottom line, they are cheap, easy to build, and they work..
 
 
http://www.ku4ay.net/dipole.html
http://www.qsl.net/kd7rem/antdipole.htm
http://www.hamuniverse.com/multidipole.html
http://www.angelfire.com/nb/ni4l/ni4ldipole.html
http://www.arrl.org/tis/info/pdf/9611073.pdf
http://www.geocities.com/n2uhc/2banddipole.html
 

 
 
by N3JBH on October 12, 2006
  FAN DIPOLE OR MULTIPLE BAND DIPOLE SPECS:
(Each leg is shown in length so you will need two legs.)
 
10 METERS = 8'4"
12 METERS = 9'5"
15 METERS = 11'1"
17 METERS = 12'10"
20 METERS = 16'8"
30 METERS = 23'2"
40 METERS = 32'9"
60 METERS = 43'7"
75 METERS = 60'9"
80 METERS = 65'6"
160 METERS = 123'5"
137 KHZ = 1708'1"
 
 
 
Tom





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AE4RV
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« Reply #2 on: July 23, 2010, 11:54:43 AM »

This is not my area of expertise but some several QSTs ago there was an article about a man who added a switchable loading coil for 160M to one of those 43' verticals that are popular now. I believe he also used a remote antenna tuner which is a good idea.

The reason I bring it up is the 43' antennas apparently don't need guy wires, which would be attractive to me, maybe you don't care.

Lots of radials Smiley


73 Geoff
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W5LZ
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« Reply #3 on: July 23, 2010, 01:08:37 PM »

Load your tower.
Paul
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KB2HUK
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« Reply #4 on: July 23, 2010, 02:10:15 PM »

Good info !  I am looking into the 43 foot guyless antenna I have a call into zerofive .  I would like to (load) my tower and make it a antenna for the low bands but all the articles use language that is beyond my understanding ( my last test was almost 20 yrs ago ) most terms and slang are not  helpful as this is my hobby not my field of expertize is anyone aware of info on this subject a 5th grader could understand ?  Thanks John
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N4NYY
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« Reply #5 on: July 23, 2010, 03:41:34 PM »

I have a Hustler 5BTV. 40M works fantastic. 80M gives me about 90 KHz band width, which is not OK. However, since I cannot stand the people on 80M anymore, so I have just abandoned it. A friend of mine in my club just brought a vertical, that does all 3 bands. I think it was over 40 feet. Someone else might know the model. 
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W7ETA
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« Reply #6 on: July 23, 2010, 05:01:52 PM »

For inverted Vee for 160 with a 60 foot tower I would consider buying a trap for 80/160 and possibly making a loading coils to get the length manageable?  You can add the 40 meter inverted Vee under it using wooden dowels to hold it in place.  Drill a hole, on both ends of the dowel,for solid wire to pass thru. Run a short piece of 18 gauge thru the dowel and then wrap each end of the wire around your dipole while keeping the dowel touching the dipole.

Some where in the articles section is a write up WB2WIK did on a a multi band vert.  Whenevr I see someone ask about a vert I think of an excellent article on W4RNL's site, "Verticals without Vertigo".  You might enjoy a refresher on verticals, especially the section about top hats and radials.

73
Bob


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WB2WIK
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« Reply #7 on: July 23, 2010, 05:30:32 PM »

A cute antenna that's prefabricated, pretuned and works pretty well for what it is: The Alpha-Delta DX-LB dipole.

It's a 3-band 40/80/160m dipole which works fine as an inverted vee.

Full bandwidth on 40, where it's about a full-sized dipole.  On 80m it's about 100 kHz bandwidth and on 160m, about 40 kHz.  Within those "windows" it works well.  Outside those windows, you can use a tuner to put power into it, but performance degrades.

I have one, and I've used it quite a bit, also hanging from a tower (at about 55 feet), so the "ends" are up about 15-20' above ground, tied off by ropes.  It's par with a 1/2-wave dipole on 40.  My "guess" is it's about 1-2 dB down on 80, and probably more like 6-8 dB down on 160, but it certainly makes lots of contacts, especially when propagation's doing most of the work. Cheesy

I've also had the GAP Voyager vertical, and it's not bad.  It works well on 40, pretty well on 80 and not great on 160 but a whole lot better than no antenna.  As Tom N6AJR said, it is a "handful" to install, and it would be nearly impossible to put up single-handedly unless you're an octopus.  But with a friend or two to help, it goes up pretty easily (it's not heavy, just very long and "bendy").
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W8JI
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« Reply #8 on: July 23, 2010, 05:48:37 PM »

If you look at reviews or measurements of the Gap antennas they are NOT good on lower bands. I had one and compared it to a 35 foot top loaded vertical, and it was about 10 dB weaker than the 35 foot vertical. While that lets you make contacts it is almost mobile antenna strength.

Independent reviews agree with this.

I also would never, not even with a loading coil, use a 43 foot vertical on 160. Unless you do some fancy work it will never take power, or never be efficient. Numbers don't lie, base voltage has to be astronomical to radiate 500 watts from a vertical 40 feet tall.

It you want a reasonable antenna for 160 and 80, install an Inverted L antenna or do the tower properly and shut feed the tower. Inverted L's are easy to do. They also, instead of being 1 to 10% efficient, would be up at 50% or more efficiency.

If you have a good Inverted L on 160 there is little reason for a dipole. Save the dipole for 80 and 40. A good dipole on 40 will run circles around a vertical.

Unfortunately no one makes a good 160 vertical that holds up well, so you are on your own with that band. There are commercial antennas that make contacts down there, but nearly all are terrible. The exception is a real expensive antenna from Germany called a Titanex.

http://www.titanex.de/verticals.html


73 Tom
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K3ANG
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Posts: 178




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« Reply #9 on: July 23, 2010, 06:03:56 PM »

If you find the prices out of your range, try building.
Like the one in the pdf below.
ymmv
73
http://www.rsars.org.uk/ELIBRARY/ANTENNAS%20DOCS/160-80-40m%20End%20Fed%20%20Antenna%20G0CSK%20iss%201.1.pdf
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