Added about a 1' chunk to the 80m segment of the 80/40/20 fan dipole.  Below is a comparison of the antenna before and after the addition.   Not allot of change ,  especially with the 80m band.  Next up adding a few feet to the 80m segment!          

    VSWR             VSWR After 1' added to        VSWR After 5' added to 80m  

  Original                     80m segment                     segment  2" removed 20m       

                                                

 80m 

Freq     

3.7             3:1                          3:1                                          3:1                                                            

3.75           1.5:1                       1.5:1                                       1.5:1

3.8             1:1                          1:1                                           1:1                     

3.85           1.5:1                       1.6:1                                        1.5:1

3.9             2.5:1                       2.3:1                                        2.2:1                       

40m

Freq         

7.0            1.2:1                    1.3:1                                            same

7.05          1.2:1                    1.3:1                 

7.1            1.5:1                    1.6:1 

7.15          1.6:1                    1.9:1

7.2            1.9:1                    2.2:1

20m

Freq     

14.0            2.2:1                3.1:1                                    >3 wont tune                        

14.05          1.7:1                2.3:1                                    3.2:1

14.1            1.2:1                1.6:1                                    2.1:1                         

14.15          1.2:1                1.6:1                                    1:1        

14.2            1.6:1                2.1:1                                    2.3:1 

Just had to sweep it with the Nano VNA

500 kHz to 60 mHz

80m

40m

20m

Sure looks like the 40m segment is a wee bit long.   80m is sure narrow band would really prefer it closer to 3.5 MHz  20m is anyones guess.   The IFL is 500' long and because of this I get allot of standing waves created on the IFL which makes it a little difficult to judge resonance.   One way of "tuning " the antenna is to add or remove IFL....doesn't make it resonant just makes it load better.

Ultimate goal is to get the desired freq under 2:1 VSWR keeping in mind a 2:1  VSWR equates to a 1 db loss in TX Power.  

So the plans is ....#1 lengthen the 80 segment then test again #2 depending on the results after lengthening the 80m segment I may want to shorten the 40m a bit.   #3 look at 20m after wrapping up the first two steps.  

20m Fan Dipole vs 1/4 Vert

 Comparing  these two antennas it was alot closer results each having its own advantage.  

The 20m Fan Dipole is at the top of the hill runs from about 260 deg to 130 deg favouring EU and AUS,  40 and 220 deg broadside.   The 1/4 Vert with 8  radials is just behind the house on the side of the hill with a GP tilted towards 200 deg.  

The fan Dipole is LDP ,  the Vert is IMI.  The fan favours EU and the Vert favors in the direction of AUS.  

The reason being is that the vert is shadowed by a big hill looking toward EU and the ground plane is tilted towards AUS.   The fan Dipole has clear LOS both directions.    

Looking out greater then 3800 km ...simultaneous spots 

and less then 3800 km...simultaneous spots 

20m Fan Dipole vs 160m Inv L

 The 20m part of the fan was tangled up with another antenna when I did the initial testing.   Corrected the problem and did another test today.  Way back when I discovered that the 160m Inv L loaded on just about all bands with the exception of 80m.   The 160m antenna acts like a long wire at the higher frequencies.  The antennas are collocated at the top of the hill being fed with 500' of LDF4.   

VE3LDP is the Fan Dipole,  VA3IMI is the 160m inv L.  

No great surprise here!   The fan blows away the 160m Inv L by about 5 db.  

In the past I compared the 160m inv l to the 1/4 Vert just behind the house and the Inv L won.   Up next comparing my 1/4 vert to the Fan.   

20m Vertical vs 20m Fan Dipole - Simultaneous WSPRs

 When I tested the 40m Fan vs 1/4 Vert  the Fan came out nearly 5 db better.  I was expecting the dipole to be 3 db better broad side with a deep null off the ends but it really wasn't all that dynamic. 

 Overall the 20m 1/4 Vert with 8 radials did better then the 20m Fan Dipole by about 3 db. 

The graph below is simultaneous spots ,  LDP the Fan  subtract IMI the Vert

Spots Map both are Green Dots,  LDP the Fan is Blue and IMI the Vert is Red 

Its really interesting when you look at simultaneous spots more the 4,000 km away.

The KH6 is more or less off the end and the EU stations are broadside.  

40m Vertical VS 40m Fan Dipole - Simultaneous WSPRs

 Both antennas are at the top of the hill.  

The 40m vertical is 3-4 years old and has 8 radials.  The Fan Dipole is new 80 / 40 /20 meters.   

The vertical is ground mounted and the Fan Dipole is up about 35' in the middle.  Most importantly dipole faces Europe broadside 50 degrees and the South Pacific broadside 230 degrees,  ends face 140 deg and 310 deg.   

 The performance of the new Fan Dipole was so much better then the Vertical I have a suspicion that I may have some losses in the IFL.     

Used 2 WSPRlites running 100 mw.  LDP is the Fan and spots are Blue Dots, IMI is the Vertical and those spots are Red but I don't see any!   The Green dots are where both IMI and LDP receives reports from.

Simultaneous Spots 

The Fan Dipole overwhelmingly comes out as the better antenna by 4.5 db ....HUGE!   

Here are the top 10 DX spots for each antenna....

Fall Antenna Work

 Did a few Antenna projects spring and summer.  

 First was the 6m vertical with 8 radial placed at the top of the hill on the ground.    It really didn't work all that well compared to the 160m inverted L which loads perfectly on the low end of 6.  Next up was a 6m dipole at the top of the hill.  It loaded right up ,  1:1 VSWR and worked well sometimes better then the  160m inverted L.    Next up was a 6 wavelength end fed 6m long wire pointed more or less south.   It worked sort of but as it turned out I had a bad chuck of IFL.  Found that out when suddenly the perfect dipole no longer loaded!     

Ripped down the 6m long wire a few weeks after putting it up its not all that practical! 

Tore down my 15/10/6 m fan dipole next to the house.   The antenna was fed with around 200' of RG6 and worked fairly well.   It was only up for a couple of years and seemed to not be as good as install.  When I took it down I found that a critter chewed through the Coax ... was surprised it worked at all!  

  Decommissioned the faulty chunk of IFL and revamped another chunk,  the original direct cable that went the 500' to the top.   About 150' from the top the original  IFL is joined.  It was well taped but somehow when I took it apart there was water in the female N-N barrel.  Blew it out ,  sprayed with contact cleaner the add two new chunks of LDF4 once again taking me to the tp of the will.     Luckly it worked and this direct run is feeding my new Fan dipole.  

Built an 80/40/20 Fan Dipole ,  its at the top of the hill it runs N NW to S SE roughly broadside to the EU and Calif and the South Pacific.  The dimensions and design were in the previous blog post.   Put it up and I really don't need to do any tuning...

80m 

Freq      VSWR 

3.7         3:1

3.75       1.5:1

3.8         1:1

3.85       1.5:1

3.9         2.5:1     

40m

Freq     VSWR

7.0        1.2:1

7.05      1.2:1

7.1        1.5:1

7.15      1.6:1

7.2        1.9:1

20m

Freq      VSWR

14.0        2.2:1

14.05      1.7:1

14.1        1.2:1

14.15      1.2:1

14.2        1.6:1

Did a bunch of cable sweeping with the Nano VNA learned a ton but thats the next blog post.   Have started to think in terms of return loss vs VSWR.  It paints a much better picture of how things are performing.   

Fan Dipole

 Planning on a fan dipole on the hill....

From this page http://www.hamuniverse.com/multidipole.html 

BUILD THIS MULTIBAND FAN DIPOLE
 FOR ALL BAND HF ANTENNA EXCITEMENT

(NEW UPDATED CONSTRUCTION TIPS FOR FASTER TUNING---SEE BELOW)

CONSTRUCTION UPDATES FOR EASIER TUNING WITH ADDITIONAL BUILDER FEEDBACK

Based on research done by the Stanford Research Institute (SRI) to construct a three-frequency multi-band dipole that would work without any need for cut and try techniques, we pass on this information in the hope that it will help you more easily get this type of antenna on the air quicker.

What they came up with was much improved method over the old cut and prune technique seen at the bottom of this page.

They found that the wires at the center feed point had to be separated by at least 5 1/2 inches vertically and the ends separated by 38 inches in the 2 to 18 MHz range. As in any fan dipole construction, all of the dipoles are connected in parallel but in the SRI method, the separation between them at the feed point must be maintained.
 
By this simple change they found that you could accurately cut the antenna element lengths for given frequencies and eliminate the need for pruning.

In the drawing above, the lowest frequency antenna is on top and is cut 4% short of the standard 1/2 wave length. (Length in feet= 0.96 times 468 divided by the operating frequency in MHz).
 
The middle frequency antenna (lower in frequency), is cut for an exact 1/2 wave length. (length in feet= 468 divided by the frequency in MHz)
 
The highest frequency antenna is at the bottom and cut for 1% longer than the 1/2 wavelength (length in feet= 1.01 times 468 divided by the frequency in MHz)

Compared to the construction effort of a standard multi-band dipole the only difference is the fabrication of a feed block or center insulator that is about 12 inches vertically by 3 inches wide, so make sure this is made of a good insulating material such as Lucite, Bakelite, fiberglass, or PVC.

The end 38 inches of separation can be maintained by separate halyards on each element or a spreader bar with a common halyard.
The bandwidth will be at least plus or minus 2% for a 1.5 to 1 SWR according to Stanford Research Institute.