Comprehensive Balun Analysis

From the results of the preliminary tests, we saw that most balun technologies failed to have enough Common Mode Impedance (CMI) for the job.  As a result the SWR curves were severely skewed on most antennas.  

 

This comprehensive test will attempt to determine how much extra attention at the feedpoint is necessary in order to get the Common Mode Current (CMC) under control.

 

In order to accomplish this we will first measure each antenna/balun by itself on all bands.  Then we will add first a Maxwell choke and measure again, followed by replacing the Maxwell with a Guanella choke and measuring again.

 

As a sanity check, I will add a 20 ft. piece of coax to the standard feedline and record how much it effeccts the "apparent" resonant point.  

 

Sounds complex and confusing now, but as we review and discuss the measured results, it will become apparent why I have chosen this test methodology.

 

TESTS OVERVIEW:

 

Test Suites:

  • Bx-BOL-xy  Test Suite, Balun Only, with 1/2 wavelength of RG-58 Coax
  • Bx-BO-xy    Test Suite, Balun Only, with 15m (49 ft.) of RG-174 HCU Coax
  • Bx-BM-xy    Test Suite, Balun + Maxwell Choke, with 15m of RG-174 HCU Coax
  • BX-BG-xy    Test Suite, Balun + Guanella Choke, with 15m of RG-174 HCU Coax

 

Each Test Suite Contains the following Data:

  • Bx-Bx(y)-AB   All Band Scan, centered on 16 MHz
  • Bx-Bx(y)-80   80m Scan, 1 MHz wide, centered on:    3.700 MHz
  • Bx-Bx(y)-40   40m Scan, 1 MHz wide, centered on:    7.200 MHz
  • Bx-Bx(y)-30   30m Scan, 1 MHz wide, centered on:  10.100 MHz
  • Bx-Bx(y)-20   20m Scan, 1 MHz wide, centered on:  14.200 MHz
  • Bx-Bx(y)-17   17m Scan, 1 MHz wide, centered on:  18.100 MHz
  • Bx-Bx(y)-15   15m Scan, 1 MHz wide, centered on:  21.200 MHz
  • Bx-Bx(y)-12   12m Scan, 1 MHz wide, centered on:  24.900 MHz
  • Bx-Bx(y)-10   10m Scan, 3 MHz wide, centered on:  29.000 MHz
  • Bx-Bx(y)-8020  80m Scan with additional 20 ft. of RG8U Coax added to feedline
  • Bx-Bx(y)-4020  40m Scan with additional 20 ft. of RG8U Coax added to feedline

I'm sure this sounds confusing, but it will become apparent when you view the actual data files for each of the baluns.

 

TEST CONFIGURATIONS:

IMPORTANT:  Though not shown in the drawings above, in ALL measurements, a Maxwell choke was attached directly to the antenna analyzer.  It was identical to the Maxwell choke used at the feedpoint in the BX-BM suite of measurements.

 

ALSO:  During the tests, I substituted 15 meters of RG-174 HCU for the RG-58. 

 

HOW TO VIEW THE DATA:

 

  • DOWNLOAD the RigExpert freeware Software, "ANTscope"
    • here:  ANTscope   (choose "Installation disk")

  • Install the software on your computer.
  • Download each of the test suites, preferably each into its own folder.
  • Run the ANTscope software, and when it opens, at the top under configure, select the antenna analyzer type (AA-54)
  • Click the Open File icon (top left and browse to the suite folder
  • Click on the data file to be opened

 

TEST RESULTS:

 

B0:  No Balun (Direct Connection)

 

Why would we test this insulator in a balun test?

 

Reason:  Curiosity killed the cat.  I just wanted to know what an 80m OCFD antenna would look like without any balun at all.  

 

Expect the worse and you probably won't be surprised! (hi)

 

 

DOWNLOAD DATA FILES:

 

B0-BO-SWR Curves with 15m Coax
Here are the B0 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the insulator and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope". This suite only contains measurements on 80 and 40m.
B0-BO Files.rar
Komprimierte Archivdatei [2.4 KB]

B1:  1:1 Guanella (W1JR) Balun

 

This choke balun is exactly like B2 (below), except it is wound on a #43 core instead of #31.  And it has an enclosure.

 

My expectation is that this one is good enough for 80m, and also good enough for the high bands.  I expect it to perform better on the high bands than B2.

 

 

DOWNLOAD DATA FILES:

 

B1-BO-Balun SWR Curves with 15m Coax
Here are the B1 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope". This suite contains only measurements on 80 and 40m.
B1-BO Files.rar
Komprimierte Archivdatei [2.5 KB]

 

B2:  1:1 Guanella (W1JR) Choke Balun

 

This choke balun was wrapped on a core with #31 ferrite.  It has significantly higher permeability than B1 above.  

 

This test will determine if such high permeability is required for 80m AND if there are any disadvantages on the higher bands when using #31 ferrite.

 

It will be tested by combining it to B0 above.  B0 provisions for wire connection.

 

 

 

DOWNLOAD DATA FILES:

 

B2-BO-Balun SWR Curves with 15m Coax.
Here are the B2 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope". This suite contains only measurements of 80 and 40m.
B2-BO Files.rar
Komprimierte Archivdatei [2.5 KB]

B3:  Balun Designs Model 4115t (modified)

 

This is a standard 4115t, with mechanical changes to better provision use with the OCFD antenna.

 

The characteristics on the high bands using a half wavelength of coax (on 80m) were not measured. Therefore there are no BOL files.  The low bands were measured in the Preliminary Tests.

 

DATA FILE DOWNOADS:

B3-Balun-Only SWR Curves with 15m of Coax
Here are the B3 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B3-BO Files.rar
Komprimierte Archivdatei [13.2 KB]
B3-Balun-Plus-Maxwell-Choke with 15m Coax.
Here are the B3 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Maxwell choke at the feedpoint, usiing 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B3-BM Files.rar
Komprimierte Archivdatei [13.1 KB]
B3-Balun-Plus-Guanella-Choke with 15m Coax.
Here are the B3 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Guanella choke at the feedpoint, usiing 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B3-BG Files.rar
Komprimierte Archivdatei [13.2 KB]

B4:  Hybrid Balun (4:1 Ruthroff + 1:1 W1JR)

 

This home-brew hybrid balun uses a voltage balun

as a 4:1 transformer, combined with a 1:1 Guanella Choke,

wound, as can be seen in the picture, in W1JR fashion.

 

It is claimed that the 1:1 Guanella has significantly more CMI than a 4:1 Guanella in the presence of high SWR. These tests

will show if that is true or not.

 

 

DATA FILE DOWNOADS:

 

B4-Balun-Only SWR Curves with 1/2 Wavelength of Coax
Here are the B4 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and one half wavelength of MIL-SPEC RG-58 coax. View files with the freeware software, "ANTscope".
B4-BOL Files.rar
Komprimierte Archivdatei [10.9 KB]
B4-Balun-Only SWR Curves with 15m of Coax
Here are the B4 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B4-BO Files.rar
Komprimierte Archivdatei [11.9 KB]
B4-Balun-Plus-Maxwell-Choke SWR Curves with 15m of Coax
Here are the B4 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Maxwell choke at the feedpoint, usiing 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B4-BM Files.rar
Komprimierte Archivdatei [12.0 KB]
B4-Balun-Plus-Guanella-Choke SWR Curves with 15m of Coax
Here are the B4 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Guanella choke at the feedpoint, usiing 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B4-BG Files.rar
Komprimierte Archivdatei [12.0 KB]

B5:  Dual-Core 4:1 Guanella Balun

 

This medium size balun had enough CMI in my 40m OCFD tests in 2013.  This test will show  if has sufficient CMI for an 80m OCFD, or if an additional RF choke is required.

 

 

DOWNLOAD DATA FILES:

 

B5 Balun-Only SWR Curves with 1/2 Wavelength of Coax
Here are the B5 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and one half wavelength of MIL-SPEC RG-58 coax. View files with the freeware software, "ANTscope".
B5-BOL Files.rar
Komprimierte Archivdatei [11.2 KB]
B5-Balun-Only SWR Curves with 15m of Coax
Here are the B5 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B5-BO Files.rar
Komprimierte Archivdatei [13.4 KB]
B5-Balun-Plus-Maxwell-Choke SWR Curves with 15m of Coax
Here are the B5 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Maxwell choke at the feedpoint, usiing 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B5-BM Files.rar
Komprimierte Archivdatei [13.4 KB]
B5-Balun-Plus-Guanella-Choke SWR Curves with 15m of Coax
Here are the B5 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Guanella choke at the feedpoint, usiing 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B5-BG Files.rar
Komprimierte Archivdatei [13.4 KB]

B6:  Dual-Core 4:1 Guanella Balun

 

This tiny balun had enough CMI for use with the 40m OCFD. Despite having 2 more turns per core, it is doubtful that there is enough ferrite mass to have sufficient CMI on 80m.  But will a Maxwell choke be all that is needed, or must we add a Guanella choke?

 

DOWNLOAD DATA FILES:

 

B6-BOL-Balun SWR Curves with 1/2 Wavelength Coax
Here are the B6 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and one half wavelength of MIL-SPEC RG-58 coax. View files with the freeware software, "ANTscope".
B6-BOL Files.rar
Komprimierte Archivdatei [12.2 KB]
B6-BO-Balun SWR Curves with 15m Coax
Here are the B6 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B6-BO Files.rar
Komprimierte Archivdatei [11.9 KB]
B6-BM-Balun SWR Curves with 15m Coax
Here are the B6 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Maxwell choke at the feedpoint, usiing 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B6-BM Files.rar
Komprimierte Archivdatei [12.0 KB]
B6-BG-Balun SWR Curves with 15m Coax
Here are the B6 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Guanella choke at the feedpoint, usiing 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B6-BG Files.rar
Komprimierte Archivdatei [12.0 KB]

B7:  Dual-Core 4:1 Guanella Balun

 

This is the largest of 3 baluns built using this design.  This version uses dual FT-240-43 toroids, each wrapped with 12 turns of Teflon-insulated twisted pair wire, 75 sq.mm. (about AWG 18).  Going into this test it expected that this version using these large cores will have nearly enough CMI for the 80m OCFD antenna.

 

We shall see if a Maxwell choke is sufficient to help this balun cope with this task, or if, like with the smaller versions, a Guanella choke is necessary.

 

DOWNLOAD DATA FILES:

 

B7-BO-Balun SWR Curves with15m Coax
Here are the B7 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B7-BO Files.rar
Komprimierte Archivdatei [13.4 KB]
B7-BM-Balun SWR Curves with 15m Coax
Here are the B7 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Maxwell choke at the feedpoint, usiing 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B7-BM Files.rar
Komprimierte Archivdatei [13.4 KB]
Download
B7-BG-Balun SWR Curves with 15m Coax - NOT YET MEASURED
UNFORTUNATELY when I got to the filed to run these tests, I discovered that I had forgotten to take along my 1:1 Guanella choke. As a result, these test results are not yet available. Sorry.
Neuer Datei-Download

B8:  Tiny Hybrid Balun

 

This 2-Core Balun consists of:

  • an LDG LBA-4, 4:1 Ruthroff Balun
  • a 1:1 Guanella Choke (see Components page)

 

Note:  This balun was tested in the very beginning, before I had decided to do this Battle of Baluns test.  This test is not as comprehensive as the tests later outlined for BoB, but the data is of some significance and has been included for the purpose of completeness.

 

The build quality of this LDG balun is nothing short of pathetic.  The wires inside are only enamel insulated, the device is not 100% waterproof, and the hardware is not even stainless steel.  

 

I cannot recomend this specific balun, however the measured results of the combination of this balun and the 1:1 Guanells choke look very good.

 

 

DOWNLOAD DATA FILES:

 

B8-BO-Balun SWR Curves with15m Coax
Here are the B8 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B8-BO-Files.rar
Komprimierte Archivdatei [12.0 KB]

B9:  Hybrid Balun using CBC Technology

 

Sorry, no further details about this balun technology are available at this time.

 

 

 

 

 

 

 

 

DOWNLOAD DATA FILES:

B9-BO Balun SWR Curves with 15m Coax
Here are the B9 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B9-BO.rar
Komprimierte Archivdatei [13.8 KB]
B9-BM Balun SWR Curves with Maxwell Choke and 15m RG-174 HCU
B9-BM-Balun SWR Curves with 15m Coax
Here are the B9 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Maxwell choke at the feedpoint, using 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B9-BM.rar
Komprimierte Archivdatei [13.9 KB]
B9-BG Balun SWR Curves with Guanella Choke and 15m RG-174 HCU Coax
B9-BM-Balun SWR Curves with 15m Coax
Here are the B9 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Guanella choke at the feedpoint, using 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B9-BM Files.rar
B9-BG.rar
Komprimierte Archivdatei [14.0 KB]

B10:  MINI HYBRID BALUN

 

This balun consists of a 1:1 Guanella Choke, followed by a 4:1 Ruthroff Balun.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DOWNLOAD DATA FILES:

B10-BO Balun SWR Curves with 15m Coax
Here are the B10 RigExpert AA-54 data files as measured on the 80m OCFD antenna with just the balun and 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B10-BO.rar
Komprimierte Archivdatei [13.8 KB]
B10-BM Balun SWR Curves with Maxwell Choke and 15m RG-174 HCU
B10-BM-Balun SWR Curves with 15m Coax
Here are the B10 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Maxwell choke at the feedpoint, using 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B10-BM.rar
Komprimierte Archivdatei [13.8 KB]
B10-BG Balun SWR Curves with Guanella Choke and 15m RG-174 HCU Coax
B10-BM-Balun SWR Curves with 15m Coax
Here are the B9 RigExpert AA-54 data files as measured on the 80m OCFD antenna with the balun plus a Guanella choke at the feedpoint, using 15m of RG-174 HCU coax. View files with the freeware software, "ANTscope".
B10-BG.rar
Komprimierte Archivdatei [13.9 KB]