Pennant and Kaz Antenna Tests

Mark Connelly, WA1ION - 2 MAY 2001

This article is a follow-on to John Bryant's article "Testing Two 'Kaz' Squashed Delta Antennas" (reference 1) and my article "Pennant Antenna with Remote Termination Control" (reference 2). At my home location in Billerica, MA during April, 2001 I installed a Kaz design antenna, named for developer and noted international medium wave DXer Neil Kazaross. After having taken some test data on it, I took this antenna down and installed a Pennant antenna of a similar configuration to the one used in my tests at West Yarmouth, MA in July 2000. For both antennas I used coaxial feedline and the Vactrol termination control scheme detailed in my previous Pennant article. Both antennas were configured so that the terminator was on the west end, since interference in the southwest to northwest sector is generally what I'm trying to null. Figures 1 and 2 show the shape and size of the two antennas that I evaluated.

Figure 1: Pennant Antenna

Figure 2: Kaz Antenna

For nulling / peaking set-ups on both antennas, the adjustable termination resistance was indirectly "measured" by recording the DC voltage present at the arm of the control potentiometer and then computing the resistance based on measured values that I included in Table 3 of my first Pennant article (reference 2). When a voltage fell between measured voltage-versus-resistance points, I used an Excel sheet to interpolate R values linearly. Maximum termination resistance, over 20K ohms, occurs at 0 volts at the arm of the controller potentiometer (i.e. no current to the LED part of the VTL5C4 Vactrol). Minimum resistance, about 54 ohms, occurs with 10 volts at the pot arm. After the voltage goes through a series of RF chokes and dropping resistors en route to the termination, the voltage actually "seen" at the Vactrol’s LED is about 2 VDC; this gives a current flow of about 25-30 mA there.

Pennant Observations

With the antenna placed for optimum nulling to the west, termination resistances in the adjustment range of 1K to 3K produced nulls of 8 to 24 dB. A 15 dB null was typical. Some nulls took a signal below the level of local electrical noise (running about S2 to S3), or below the level of another co-channel station, or below the "slop" from an adjacent channel station. In those cases, I did not enter a null depth value in the Excel calculation table. Stations in or near the null bearing (west) had peak signal values when the termination was set to one of the end scale values: 54 ohms, or greater than 20K. Most of the time, for stations in the southwest to northwest sector, the minimum termination value of 54 ohms "de-nulled" the signal to the greatest extent.

Stations close to a right angle to the plane of the antenna – north or south in my case – nulled best with termination resistances between 54 ohms and 1K. Null depths were shallower, about 3 to 12 dB typically. Because resistance values dialled up for stations north or south were similar, the pattern produced was likely figure-of-eight rather than cardioid at those settings. Peak pick-up of these right-angle stations was usually at maximum termination resistance (> 20K).

Nulls of stations in the desired pick-up area (the northeast to southeast sector) were, as expected, very shallow: typically 0 to 7 dB. Variation was often hard to observe. Minimum signal pick-up generally coincided with minimum termination resistance. Maximum signal strength characteristically occurred at maximum resistance; however, at values that worked for west-nulling (e.g. 1K – 3K), signal strength of easterly stations was close to the achievable maximum.

Kaz Observations

The Kaz Antenna operated very similarly to the Pennant with the following distinctions:

(1) Null depth was SLIGHTLY (~ 1.5 dB) better in the desired southwest to northwest "kill zone". The spreadsheet showed 16.6 dB to be a typical null-depth value. Some nulls as good as 28 dB could be obtained.

(2) Termination resistance required to effect a null was somewhat higher than on the Pennant. For stations on close to westerly bearings, typical termination resistance values were in the range of 1.4K to over 8K. This performance may have been the result of the antenna being fairly close to the house and to its own coaxial feedline as well as to another coaxial line coming from the sloper.

Comments Applicable to Both Antennas

The Vactrol remote termination scheme is a MUST ! I’m amazed at the great results John Bryant had with a single fixed termination resistance value. I feel that you are going to have to adjust your termination resistance over a range of at least 500 ohms to 5K ohms unless you have these antennas constructed in a perfectly open area away from houses, power lines, coaxial lead-ins, other antennas, metal masts, and maybe even trees. That applies even if you only want to null stations on bearings within +/- 30 degrees of the design direction. I feel that the ability to "slew" the null over a much greater bearing range is a nice side benefit of the Vactrol system. Admittedly nulls more than 30 degrees away from the design direction aren’t maximum depth, but they can still be useful. As far as phasing goes, setting up two Pennant or Kaz antennas at a spacing of 1/8 to 1/4 wavelength is the best way to go, but if you have to position them closer, either orient them differently or make one different from the other by using different termination resistances. Minimum resistance (even a dead short) to terminate one of them would yield a minimal null where something like 1K on the other antenna would produce a substantial null. Phasing two antennas set up this way could be very useful.

These terminated loops are somewhat more susceptible to local electrical noise pick-up than a conventional balanced (tuned or broadband) loop is. Place the antenna in a relatively quiet area and things should be OK.

Signal capture (sensitivity) of both the Pennant and Kaz antennas, as configured here, was very similar. I did not use an amplifier, though one having about 20 dB gain is seriously recommended – especially for rural DXers – because the signal levels obtained from a Pennant or Kaz antenna of the sizes I tried is about 20-23 dB lower than that from a 30 m (100 ft.) sloper via 4:1 transformer.

Both antennas, because of the adjustable termination resistance, were often superior to the sloper in reducing nighttime skip from domestic stations in the southwest to northwest design sector. I could even make a dent in "superpests" WPTR-1540 and WQEW-1560, two of the most difficult stations to null here at night. Around local midnight, reception of numerous high band stations from Spain and France was usually about the same (in terms of audibility if not S-meter level) when I switched between the "workhorse" Euro-sloper and the Pennant or Kaz antenna under test.

A full set of the Pennant test data is available in a PDF format (reference 3). The complete Pennant-versus-Kaz Excel sheet is obtainable in a downloadable ZIP file (reference 4).

The table below demonstrates the performance of the Pennant and Kaz antennas on a short list of stations monitored under daytime groundwave conditions at Billerica, MA.

Pennant versus Kaz Antenna Tests: a sampling of stations

DAYTIME BANDSCANS - 19 & 27 APR 2001 -BILLERICA, MA - (GC= 71.221 W / 42.533 N)

Sorting order is by bearing (degrees clockwise of true north)

 

 

 

 

 

Pennant

Pennant

Pennant

Pennant

Kaz

Kaz

Kaz

Kaz

Sloper

Bearing

Dist.

Freq.

Call

State

peak

Null

PK-N

Null R

peak

null

PK-N

Null R

max.

degrees

Km

kHz

 

 

dB o/0

dB o/0

dB

ohms

dB o/0

dB o/0

dB

ohms

dB o/0

173.25

28.00

1600

WUNR

MA

57.0

52.2

4.8

54

58.0

49.2

8.8

314

86

176.77

12.96

1150

WAMG

MA

68.0

56.0

12.0

275

68.0

57.0

11.0

444

93

185.81

84.46

630

WPRO

RI

40.8

26.4

14.4

432

43.2

27.0

16.2

551

60

186.36

83.77

920

WHJJ

RI

45.6

39.6

6.0

524

42.0

34.8

7.2

707

58

187.90

28.29

850

WEEI

MA

75.0

62.0

13.0

618

72.0

61.0

11.0

1135

99

207.63

35.51

890

WBPS

MA

56.0

46.2

9.8

1060

58.0

43.2

14.8

2285

81

207.63

35.51

650

WJLT

MA

44.4

34.8

9.6

1172

49.2

33.0

16.2

1920

66

212.68

32.08

1200

WKOX

MA

65.0

52.8

12.2

942

63.0

56.0

7.0

1833

93

212.90

32.02

1060

WBIX

MA

75.0

61.0

14.0

1141

72.0

61.0

11.0

2110

96

229.78

282.65

880

WCBS

NY

39.6

25.2

14.4

2096

40.2

12.0

28.2

8460

52.2

235.28

59.84

1310

WORC

MA

49.2

38.4

10.8

1250

50.4

40.2

10.2

1570

71

241.92

19.25

1120

WBNW

MA

64.0

52.8

11.2

1250

62.0

49.8

12.2

2608

91

241.94

66.34

830

WCRN

MA

58.0

36.0

22.0

2993

60.0

43.2

16.8

8383

81

242.97

34.12

1470

WSRO

MA

50.4

32.4

18.0

1154

51.6

30.6

21.0

1408

72

246.39

77.09

760

WVNE

MA

46.2

24.0

22.2

2154

51.0

27.0

24.0

5611

67

269.21

42.24

1000

WCMX

MA

48.6

40.2

8.4

1558

46.8

39.0

7.8

2531

66

278.28

51.02

1280

WEIM

MA

54.0

42.0

12.0

1486

56.0

43.2

12.8

1877

80

320.03

18.07

980

WCAP

MA

65.0

53.4

11.6

787

60.0

56.0

4.0

999

94

320.61

33.06

900

WMVU

NH

49.8

43.2

6.6

951

50.4

42.0

8.4

>20K

77

334.85

46.38

1370

WFEA

NH

52.2

40.2

12.0

498

46.8

39.0

7.8

736

76

344.85

55.99

610

WGIR

NH

44.4

32.4

12.0

395

43.2

39.0

4.2

1197

71

AVERAGE OF PEAK-NULL (dB) IN 225 - 285 DEGREE DESIGN SECTOR:

 

 

 

 

 

14.9

16.6

 

 

 

 

 

 

 

 

Pennant

 

 

 

Kaz

 

 

AVERAGE OF PEAK LEVELS (SENSITIVITY BENCHMARK) (dB over zero):

 

 

 

 

 

54.7

54.5

77.6

 

 

 

 

 

Pennant

 

 

 

Kaz

 

 

 

Slopers

 

References:

(Note: Over time Web URL's may change. If this occurs, it may still be possible to retrieve the articles by going to known DXer Web sites or to search engines for links. Hard copies are likely to be available from the National Radio Club and International Radio Club of America reprints services.)

1. Testing Two 'Kaz' Squashed Delta Antennas, John Bryant, 2001
"kaztests.pdf"

2. Pennant Antenna with Remote Termination Control, Mark Connelly, 2000
"pennant.pdf" and"pennant.htm"

3. Pennant Antenna Test Data – Billerica, MA, Mark Connelly, 2001
"billerica_pennant_test.pdf"

4. Pennant versus Kaz Antenna Test Data, zipped Excel sheet, Mark Connelly, 2001
"bscan_billerica_pennant_kaz.zip"

 

Appendix: Independent Pennant Antenna Testing by Ken Alexander in Ontario, Canada

From: "Ken Alexander" <kpathai@hotmail.com>

Sent: Wednesday, April 25, 2001 8:26 PM

Pennant Antenna Review and Impressions

After several days of scrambling around to collect parts, build circuit boards, and package everything up I was finally able to spend this past weekend testing my first pennant antenna.

The antenna was modelled using EZNEC. The intention was to create an antenna that would cover the medium wave band and down into the longwave band. After experimenting with several different sizes I settled on sizing it by making the end 0.015 wavelengths high and the sides 0.05 wavelengths long at 900 kHz. I arrived at these sizes after trying several different sizes that were close. After a while I sat back and worked out what the sizes I had been using were as a fraction of a wavelength and realized I was close to 0.015 and 0.05. The first time I ran my model using these figures the model performance jumped. I was so pleased with the improved performance I decided to stick to this size. The dimensions work out to 16.4 ft high with sides 54.6 ft long.

Next I built the pennant termination control package as designed by Mark Connelly. I must say that Mark's control package worked very well. However, most of the nulls occur within 5 or 10 degrees of the rotation of the pot and it requires the delicate touch of a brain surgeon to find the deepest part of the null. I may try adding a second pot to act as a fine tuning control. Regardless, it did work very well!

The antenna was made of #14 stranded appliance wire and was erected between two trees at our weekend DXpedition site in Coe Hill, Ontario. As luck would have it, the trees placed the antenna at a bearing of 43 degrees, which aims the null directly at the Toronto/Hamilton area (at 223 degrees) and the forward lobe directly towards Europe, exactly what we are after! The bottom of the antenna's vertical section was approximately 3 ft off the ground.

The antenna was used on Friday night without an amplifier, but the results were gratifying! The LCD bargraph S-Meter on my AOR 7030 isn't conducive to accurate meter readings so I recorded what I could, and relied on what my ears told me. Stronger stations from Toronto such as CFTR-680 and CHWO-740 with S9+10dB signals could generally be nulled to S3 to S5, where they began to disappear in the background clutter. WJR-760 from Detroit, about 17 degrees off the null axis could be removed completely, of course it's a weaker station to begin with so it doesn't take as much to make it disappear.

On Saturday, I built an amplifier based on a Mini-circuits ERA-4SM integrated circuit amplifier and added it on. This brought signals up to the levels we are used to seeing from out 1000 foot beverage antenna, and finally I was completely happy with my Pennant antenna. I spent the latter part of Saturday afternoon going through the MW band and have listed my observations below:

Freq

Station

City *

Un-nulled

Nulled

Bearing**

Remarks

530

CIAO

Toronto

S8

S3

225

Barely readable

560

CFOS

Owen Sound

S6 to 7

S3+

270

-

590

CJCL

Toronto

S9+5

S6

224

-

610

CKTB

St. Catharines

S9+5

S6

213

-

640

CFYI

Toronto

S9+10

S7

224

-

680

CFTR

Toronto

S9+10

S5

220

-

710

CJRN

Niagara Falls

S7

S4

208

Gone in clutter

740

CHWO

Toronto

S9+10

S3

228

Almost gone

760

WJR

Detroit, MI

S5

S3

240

Gone in clutter

770

WTOR

Buffalo, NY

S8 to 9

S3

205

Gone in clutter

800

CJBQ

Belleville

S9+15

S9

185

-

820

CHAM

Hamilton

S9+10

S4

223

Barely audible

860

CJBC

Toronto

S9+10

S3

228

Gone in clutter

900

CHML

Hamilton

S8

S3

223

Gone in clutter

920

CKNX

Wingham

S7

S4

~260

Barely audible

950

WBBF

Rochester, NY

S7+

S6

180

Gone in clutter

980

CKRU

Peterborough

S9+20

S9

182

-

1010

CFRB

Toronto

S9+5

S6

228

-

1040

WYSL

Avon, NY

S7 to 8

S3

200

Gone in clutter

1050

CHUM

Toronto

S9+5

S5

226

Almost gone

1080

WUFO

Amherst, NY

S6 to 7

S3

202

Gone in clutter

1120

WMNY

Buffalo, NY

S6 to 7

S3

203

Gone in clutter

1140

WCJW

Warsaw, NY

S7

S3

?

Gone in clutter

1180

WHAM

Rochester, NY

S9+10

S7

180

-

1210

WPHT

Philadelphia, PA

S7

S3

~150

Gone in clutter

1250

CJYE

Oakville

S9

S6

231

-

1270

CJTN

Trenton

S9+10

S7

184

-

1330

WFNN

Erie, PA

S6 to 7

S3

213

Gone in clutter

1350

CKDO

Oshawa

S9+5

S7

223

-

1420

CKPT

Peterborough

S9+15

S7

182

-

1440

WJJL

Niagara Falls, NY

S8

S3

208

Gone in clutter

 

Notes:

* - all stations are in the province of Ontario except as noted

** - bearings are degrees from true north, taken from Coe Hill, Ontario

Impressions:

I've tried several different antennas at our Coe Hill site in an effort to reduce local station interference so we could DX European MW stations. At different times these have included:

The best setup has been a 1000 ft terminated beverage as the main antenna phased against a 1000 ft unterminated beverage with the MFJ phasing unit. Both antennas are installed at a bearing of 45 degrees and approximately 100 ft apart (that's the best separation we can manage with the coax we have).

This setup is very effective but there are several problems:

The Pennant seems to be the answer to our problems. It has a nice, deep null, it can be set up in minutes, and nulling is simple compared to phasing. Propagation last weekend wasn't good enough to hearing anything more than weak carriers from Europe, but once the amplifier was installed the carriers were no weaker on the Pennant than they were on our beverage. This bodes very well for when the DXpedition Season starts again next September.

Final Note: The last thing I did last week before sneaking away from work early to head to our DXpedition site was to print out John Bryant's review of the KAZ. I read it after setting up my Pennant. Since returning I modelled the KAZ with EZNEC and am encouraged by what I find. Now that the electronics for the Pennant are built and working well the next thing I will try is the KAZ configuration!

73 - Ken

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