Re: Antennas [was CQWW DX]


Christopher Scibelli
 

Scott,
 
What was your friend using on 40 meters when I worked you guys on 10/19?  My log shows you at 59 +20 and WC3N at 59+30.  Were you two using the same power?
 
73,
 
Chris  NU1O
 

In a message dated 10/26/2015 6:28:25 A.M. Eastern Daylight Time, N3FJP_Software_Users@... writes:
 

Hi Bob,


I don't have any experience with OCF dipoles.  I can tell you that the combination of my two antenna sets of traditional dipoles, each at 6/10 of a wavelength high and delta loops (which also work well - about as the same as dipoles) at 90 degree from each other continue to perform fine (http://www.n3fjp.com/antennas/index.html).  Another local ham, Gary, WC3N, who has a hex beam and I have done a lot of comparative testing.  In most cases I'm 1/2 - 1 S unit lower than the beam, which is about the 3 - 6 db you would expect.  

During this past weekend's CQ WW SSB, I wound up with 733 Qs, while my hex beam buddy worked 927.  This is not a direct comparison of a hex beam to dipoles as we were not operating at 100% identical times, but subjectively I think it is pretty reflective of how they compare.  I could work just about all the stations that Gary could, but on the random occurrences where we both happened to call a station at the same time, Gary got through before me almost every time.  Spending time breaking pile ups is a QSO rate killer and the primary reason for the hex beam's better result.

The article below well covers what we are experiencing here.  I'm overcoming a good bit of the dipole nulls the article discusses with my two sets of antennas at 90 degrees.  That all said, Lord willing, I may put up a hex beam next year for that additional S unit.  We will see...

From:

http://www.k4kio.com/hexagonal-beam-compared-with-a-dipole/

Hexagonal beam vs Dipole

How does the hexagonal beam compare with a dipole?
The dipole is actually a pretty good antenna. You can build one with very little expertise and only a few dollars, using trees as masts. They perform well in many cases and for the low frequency bands such as 80, 40 and 30 meters, they are not competing with directional antennas so everybody can be on a level playing field. Get an amplifier and become the big signal on your 75 meter net.
How about for DX and the bands above 30 meters? Well, the dipole still is a good performer and is even easier to install because it doesn’t take a large lot to put one up. Plus, you can get a respectable takeoff angle for good skip with a dipole at only 40 feet or so. When stations are broadside to the dipole, the dipole performs only slightly less than a hexagonal beam. The hexagonal beam has gain of about 3 dB over a dipole when the target is broadside to the dipole as shown on the azimuthal radiation pattern chart to the right. The Blue trace is the dipole pattern and the red trace is the hex. So if a DX station (shown North in this example) is broadside to the dipole, the dipole station is going to break the pileup about as well as the hex. So the dipole really does a decent job in some directions.
But what about a station that is off the end of the dipole (east in this example)? Well, this is a different story altogether and shows the big advantage of a hex. The hex just turns east toward the DX target and you can see the difference on the chart below. Now the dipole has a 10 dB disadvantage or about 1/10 of the signal that the hex has. This is the most obvious advantage of a directional antenna. But that’s not all.
The dipole station while sending a signal only 1/10 of the hex signal, is receiving signals from stations north and south that it really has no interest in. This is QRM big time. So the dipole station has troublehearing the DX station because the DX signal is down 10 dB compared to how the hex station is hearing it and on top of that the dipole station is getting all that QRM from unwanted stations. Notice that the hex is not getting this unwanted QRM because the hex suppresses reception from unwanted directions.
These two factors, directionality and back/side signal suppression are what make the hex a huge winner over a dipole in most instances. Again when broadside, the dipole does a respectable job but because it can’t be rotated, more times than not it has a big handicap in snagging the DX. This limitation of the dipole is generally the case for any fixed wire antennas such as G5RV’s, doublets, windoms or whatever.




73, Scott
N3FJP
 
Serving the Amateur Radio community with contesting and general logging software since 1997.
 
1 Peter 3 vs 15: Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect...
 
 


-----Original Message-----
From: Robert rit001@... [N3FJP_Software_Users]
To: N3FJP_Software_Users
Sent: Sun, Oct 25, 2015 1:52 pm
Subject: Re: [N3FJP_Software_Users] CQWW DX

 
Scott good morning,

Just viewed you video on antennas, very helpful thank you. I'm using a Windom OCF antenna up about 20'. Your thoughts. 

73 Bob
WA6MBL



On Oct 25, 2015, at 2:02 AM, Scott & Kimberly Davis SNKDavis@... [N3FJP_Software_Users] <N3FJP_Software_Users@...> wrote:

 
Thanks Larry,

I was up to about 300 Qs as of 2:00 PM eastern yesterday with my dipoles and loops (http://www.n3fjp.com/antennas/index.html) but then we got some unexpected, (but delightful) company, who stayed the rest of the day.  Conditions are GREAT!!!!  Getting ready to get cranked back up now!

Bill, there isn't a way to show reverse path at this time.

Have fun all!


73, Scott
N3FJP
 
Serving the Amateur Radio community with contesting and general logging software since 1997.
 
1 Peter 3 vs 15: Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect...
 
 


-----Original Message-----
From: 'Larry Stowell' lclarks@... [N3FJP_Software_Users] <N3FJP_Software_Users@...>
To: N3FJP_Software_Users <N3FJP_Software_Users@...>
Sent: Sun, Oct 25, 2015 4:36 am
Subject: Re: [N3FJP_Software_Users] CQWW DX

 
Thanks Scott
 
I am enjoying!!
 
73 Larry K1ZW
 
Sent: Saturday, October 24, 2015 8:37 PM
Subject: Re: [N3FJP_Software_Users] CQWW DX
 


Hi Larry,
 
CTRL+Shift+C Display Bearing as compass heading

Enjoy!
 
 
73, Scott
N3FJP
 
Serving the Amateur Radio community with contesting and general logging software since 1997.
 
1 Peter 3 vs 15: Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect...
 
 


-----Original Message-----
From: lclarks@... [N3FJP_Software_Users] <N3FJP_Software_Users@...>
To: N3FJP_Software_Users <N3FJP_Software_Users@...>
Sent: Sat, Oct 24, 2015 7:26 pm
Subject: [N3FJP_Software_Users] CQWW DX

 
I know I'm missing something simple. I don't see how I change the bearing from compass to degrees?
I know where it is in ACLog appearance and my othe contest programs came up with  degrees.
 
73 Larry K1ZW

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