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

   Home   Help Search  
Pages: Prev 1 [2] 3 Next   Go Down
  Print  
Author Topic: S9 31 FOOT VERTICAL  (Read 7841 times)
W5DXP
Member

Posts: 3621


WWW

Ignore
« Reply #15 on: November 05, 2012, 06:19:05 AM »

In 2 years, 37,000+ QSO's, 223 countries, 5 Band DXCC.

That's quite an accomplishment for 6m only operation - especially the 5 band DXCC.Smiley Hint: The 40 degrees take-off-angle I was talking about was only in the context of 6m operation as can be seen from the posting to which I was responding. Can we hear it from hams who use a 31 ft. vertical on 6m? How does it perform on 6m? Any 6m DXCC using a 31 ft. vertical?
Logged

73, Cecil, www.w5dxp.com
The purpose of an antenna tuner is to increase the current through the radiation resistance at the antenna to the maximum available magnitude resulting in a radiated power of I2(RRAD) from the antenna.
AG6WT
Member

Posts: 461




Ignore
« Reply #16 on: November 05, 2012, 06:22:59 AM »

Another option is to add 10-15 feet of wire to the top and pull it out horizontally or nearly so with some light line. You'll essentially have a bent over 43' vertical which should be easier to tune on 80-10 with the unun and tuner at the rig. The optimal length will depend on such factors as the angle of the extra wire and your radial field. It will be an inverted-L but as only a small part of the wire is horizontal the radiation pattern will be more like a true vertical antenna.

Ray KJ6AMF
Logged
K5USF
Member

Posts: 83




Ignore
« Reply #17 on: November 05, 2012, 08:14:42 AM »

At first I used a manual shack tuner and a 1:4 unun.  No problems tuning 80-10m.  I did add a shunt coil and tuned base coil for 80m to improve the Z.  Now, I use a remote, home brew tuner at the base, a 1:1 current choke and 75 feet of 1/2 inch hardline.  Continues to tune fine on 80-10m.  Wouldn't waste your time on 160m or 6m.  Jim
Logged
KE2TR
Member

Posts: 177




Ignore
« Reply #18 on: November 07, 2012, 09:20:46 PM »

The 31' vertical is almost a full 1/4 wave for 40ty, maybe add two turns of wire at the base and you just might get it to resonate by itself on 40ty, the other bands its gonn be like a G5RV with some low angle. I tryed a 43 ft vertical, it worked real well on 20 were it was 5/8ths wave but sucked everywere else, tryed 75 and it was kinda light on that band so I did  LL job of loading and mde it a 75mtr only antenna but Sandy blew it apart so it bck to the drawing board.
Logged
K2OWK
Member

Posts: 1066




Ignore
« Reply #19 on: November 08, 2012, 02:45:29 PM »

I checked the UNUN on my 31 foot antenna and all looked well. I tightened some connections and reinstalled it at the base of my antenna. Now for some crazy reason it tunes all the bands with the exception of 40 meters using my MFJ-914 Auto Tuner Extender. I checked it with my MFJ antenna analyzer and it showed all the tunable bands can be adjusted to better then a 3 to 1 VSWR (even the upper part of 80 meters). I am still getting the MFJ-949E just in case something changes again. What a strange experience. The antenna works absolutely great on both transmit and receive. I am very pleased with the S9.

Thanks for all the great advice as this is my first vertical.

73s

K2OWK
Logged
W5WSS
Member

Posts: 1745




Ignore
« Reply #20 on: November 11, 2012, 12:02:34 PM »

I used a 31 ft vertical wire originating from the window sill that went upwards to a tree .
I connected the coax shield to tuned elevated sloping radials from the exact window sill two per band lowest frequency to highest frequency out to the farthest insulated dead end plastic stakes so when all were installed they looked like cat whiskers from the source outward or as viewed from above the lowest and longest pair first to shortest directly below.
With the use of an LDG 200 pro auto tuner at the feedpoint the system tuned from 6m to part of 75m.
This 31ft vertical with two pairs of tuned elevated radials at 5 ft base height developed the expected pattern expected means: length of vertical to Tao ratio.
Not included is the debate on how many radials are best for proper pattern modeled but rather a minimal radial set of elevated radials for getting on the air from a vacation cottage.
As a general one can expect with slightly varying results where the length of the vertical is close to a quarter wave then one can expect the lower angles to manifest for transceiving  remembering as the antenna is a fixed length and frequency is varied then the length to Tao changes thus if we press the 31 ft vertical into a tuned matched state we still follow the mandate that the length dictates the manifested Tao.

My findings with this type of system my 31 ft version with a pair of elevated tuned radials where frequency applied mandates a near quarter wave physical length will be a gratifying system pursuant to dx work for example,when used to around the area of bands that limits the length to a quarter wave to a 5/8 wave respectively.
As the antennas physical length in percentage increases beyond the 5/8 wave the Tao manifests at higher and higher angles and the antenna utility changes to transceiving sensitivity for closer and closer skywave work.
Logged
WB6BYU
Member

Posts: 13341




Ignore
« Reply #21 on: November 11, 2012, 12:09:37 PM »

Quote from: Lao Tse

The Tao that you can see is not the true Tao.

Logged
KO7I
Member

Posts: 106




Ignore
« Reply #22 on: November 17, 2012, 10:38:33 AM »

I have a resonant 40M quarter wave vertical in my back yard. It is fed with 100 ft of RG-213 and I have 66 32ft long radials stappled down in my lawn. On 40M I drive the antenna with 900W. Using a MFJ model 929 auto tuner I can get my vertical/coax/radial system to "load" on all bands 80 thru 10 mtrs. It is noted that on the non-reasonant bands I am very careful to limit the transmit power to 100W.

While I do not advertize this as a cure all solution, it works, well sort of. Not "that bad" on 30 & 20 meters.

As already suggested, I would dump the 4:1 balun it is not helping you. I would take all extra coax and roll it up into a 6" dia coil near the entry point to your house to help de-couple stray RF on the shield of your coax.

You mentioned RG-8X, you need to carefully inspect the connector at the feed point of the antenna and make sure water had not inflitrated your coax cable.

73, Don KO7i
Logged
N4JTE
Member

Posts: 1158




Ignore
« Reply #23 on: November 17, 2012, 06:50:20 PM »

Reality check, there is no way 30 ft of wire or alum. in any configuration is gonna be a multiband efficent antenna, no matter what extensive ground system or tuner you might add.
Amazing how the advertisments try to forget the laws of physics.
Most times your feedline is your emmiter when off anything beyond 40 meters, think Tak antenna and the isotron, it is what it is, and good for limited expectations when small area for real antennas.
Bob
Logged
W5DXP
Member

Posts: 3621


WWW

Ignore
« Reply #24 on: November 17, 2012, 07:31:10 PM »

Reality check, there is no way 30 ft of wire or alum. in any configuration is gonna be a multiband efficent antenna, no matter what extensive ground system or tuner you might add.

30 ft of conductor is close to 1/4WL on 40m. 1/4WL is known to be an efficient vertical radiator.

30 ft of conductor is close to 1/2WL on 20m. 1/2WL is known to be an efficient vertical radiator.

30 ft of conductor is close to 5/8WL on 17m. 5/8WL is known to be an efficient vertical radiator.

All one needs for efficient multiband performance is a good power delivery system which includes a conjugate match and low-loss transmission line.
Logged

73, Cecil, www.w5dxp.com
The purpose of an antenna tuner is to increase the current through the radiation resistance at the antenna to the maximum available magnitude resulting in a radiated power of I2(RRAD) from the antenna.
KO7I
Member

Posts: 106




Ignore
« Reply #25 on: November 17, 2012, 09:02:54 PM »

Reality check, there is no way 30 ft of wire or alum. in any configuration is gonna be a multiband efficent antenna, no matter what extensive ground system or tuner you might add.
Amazing how the advertisments try to forget the laws of physics.
Most times your feedline is your emmiter when off anything beyond 40 meters, think Tak antenna and the isotron, it is what it is, and good for limited expectations when small area for real antennas.
Bob

Yupp!! Never said a non resonant ant fed with 75ft of coax works great - just said it would "load up".  Shocked

base loading that chunk of wire with a remote tuner would help reduce transmission line losses provided it has an efficient ground system.

73, Don KO7i
Logged
K2OWK
Member

Posts: 1066




Ignore
« Reply #26 on: November 17, 2012, 09:10:25 PM »

Hello everyone. I kind of ended this post on a second post called UNUN/Balun. The S9 antenna using a 4 to 1 UNUN with an MFJ-914 Auto-tuner extender and an MFJ-949E manual antenna tuner (for 40 meters only), will now tune the bands from 80 thru 6 meters. It is a fantastic antenna regardless what the laws of physics say. Using my Yaesu FT-450AT at 100 watts, anyone I can hear I can talk to. I have made many contacts with this set up. I am very pleased with what I have, and now see why the S9 has such an excellent review.

Talk to you on the air.

73s

K2OWK
Logged
KB1GMX
Member

Posts: 782




Ignore
« Reply #27 on: November 18, 2012, 10:44:06 AM »

>>>30 ft of conductor is close to 1/4WL on 40m. 1/4WL is known to be an efficient vertical radiator.

30 ft of conductor is close to 1/2WL on 20m. 1/2WL is known to be an efficient vertical radiator.

30 ft of conductor is close to 5/8WL on 17m. 5/8WL is known to be an efficient vertical radiator.

All one needs for efficient multiband performance is a good power delivery system which includes a conjugate match and low-loss transmission line.<<<


Actually line loss is mostly not the real issue.  Its making the transmitter happy that is the concern.

At 40M its fine direct fed.  However at 20M its and end fed half wave vertical and the feed point is
above 2000ohms so feed point correction to get it down some is a must.   On 17M the feed point resistance is not so much the issue as the reactance is very high.

It would be very easy to put an auto tuner at the base and that would solve most problems save
for above 15M it's too long and the RF takeoff angle is up and forget 6M.  Just because a vertical
can take power at 6M that doesn't make it useful as the polarization is wrong for SSB (save for
E-season where wet noodles work).   The biggest issue with these all band verticals is the numbers
for gain and pattern make little sense as in ineffective or wrong polarization when you get too high
in frequency.  At some point say 10M a vertical dipole is only 16.5 ft tall (or long) and easily hide. 
If you need a 6M antenna make a horizontal wire dipole its only about 116 inches long and only
needs to be 20ft up to be very effective.

So for 80 through 15m a simple relay switched network of coils and caps would make the feed point
nearly 50 ohms cheaply.  With a bit more effort it's possible to make a match network that keeps the
feed point SWR under say 300ohms and above about 20 ohms making it an easy match for most transceiver tuners and if RG213 were used the losses would be trivial.

For HF the one do all antenna of any height (save trapped systems for other discussions) suffers
from far to many compromises.   That and any claim of low SWR is meaningless as an indicator of usefulness (besides making the solid state finals happy).  If you have power to burn then put a
wide range tuner on the desk and stop worrying about the cable loss.


Allison
Logged
W5WSS
Member

Posts: 1745




Ignore
« Reply #28 on: November 18, 2012, 11:52:51 AM »

Bob, I built and used one with the prior knowledge that when we design for proper delivery then the mandate of a 31ft length is exactly as I have just previously stated.

As Myself and Cecil and others have experienced in the real" that the zone of frequencies where the length in this case a 31ft monopole is specifically pressed and held from between a band where the 31 ft is equal to a 1/4 up to a 5/8 wave will perform a utility of lower angle manifested power radiation conducive to the pursuit of long range dx work.

This is always what the monopole can deliver when we design a delivery system that can stand up to the pressure when the frequency applied to the monopole and the length is a halfwave in this case 31 ft would fall on 20m service. yes the pressure is greater on the network but that does not change the power manifested TOA.

Our design parameter challenge is not only in optimizing the antenna but in providing a network that can handle the 1/2 wave pressure imposed on both the network integral Balun and auto tuner.

The Monopole and network,Balun as a system can offer excellent multi band utility when one understands what to expect.

I used 3 quick change vertical lengths 22ft,44 and 66ft and expected excellent long range dx communications and the system offers excellent service when we deliver via a network designed for the job.
Logged
W5DXP
Member

Posts: 3621


WWW

Ignore
« Reply #29 on: November 18, 2012, 04:06:47 PM »

Its making the transmitter happy that is the concern.

Actually, personification of an inanimate transmitter may be the biggest concern. Smiley Assuming that a transmitter is actually capable of human emotions, I guarantee that a conjugate match will make the transmitter happy. What could possibly make a transmitter happier than delivering all of its available power to the load?
Logged

73, Cecil, www.w5dxp.com
The purpose of an antenna tuner is to increase the current through the radiation resistance at the antenna to the maximum available magnitude resulting in a radiated power of I2(RRAD) from the antenna.
Pages: Prev 1 [2] 3 Next   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!