Antennas

Frank Donovan, W3LPL

Antenna Secrets of the Top Multi-Op Stations

Revealed !How do the top multi-op stations break those huge pileups so fast?

How do they consistently make 5000 to 8000 QSOs in one weekend ?

Of course, they have great operators, full legal power, great locations, and they’re really serious competitors...

But that’s not enough ! Its not even close...

They all use stacked monoband Yagis at carefully chosen heights

But the most competitive multi-ops do much more…

The antenna secrets of the Top Multi-ops...And tips to apply to your own station!

Secret #1: Use All of the Right Angles

Do your antennas cover all of these elevation angles?The top multi-ops cover them all (or almost all…)

Europe Asia/Pacific80M 10 - 30 deg (100 - 200 ft) 7 - 18 deg (150 - 200 ft) 40M 7 - 23 deg (100 - 200 ft) 5 - 15 deg (120 - 200 ft) 20M 5 - 18 deg (75 -100 ft) 4 - 12 deg (100 - 200 ft) 15M 4 - 15 deg (60 - 90 ft) 3 - 10 deg (90 - 200 ft)10M 3 - 12 deg (50 - 80 ft) 2 - 8 deg (80 - 200 ft)

Secret #1: Use All of the Right Angles

Of course, its extremely difficult to cover all of the right angles

So…

Tip #1: Design your antennas for as many of the right angles as you can. A good compromise is:

50 - 100 feet for Europe 80 - 100 feet (plus) for Asia/Pacific

Secret #2: Eliminate Radiation Pattern Nulls

Low antennas have clean radiation patterns- with no nulls- but poor low angle radiation

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5 Element 20 Meter Yagion 48 Foot Boom, 50 Feet High

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50 FT

5 degrees

Europe

Poor low angleradiation

18 degrees

No nulls...

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5 Element 20 Meter Yagion 48 Foot Boom, 50 Feet High

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50 FT

4 degrees

Asia/Pacific

Poor low angleradiation

12 degrees

No nulls...

Secret #2: Eliminate Radiation Pattern Nulls

High antennas produce excellent low angle radiationbut have deep nulls at very important elevation angles

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5 Element 20 Meter Yagion a 48 Foot Boom, 200 Feet High

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Deep nullEurope

12 degrees

4 degrees

Excellent low angleradiation

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5 Element 20 Meter Yagion a 48 Foot Boom, 200 Feet High

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Deep null

Asia/Pacific

12 degrees

4 degrees

Excellent low angleradiation

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6 Element 15 Meter Yagion a 48 Foot Boom, 200 Feet High

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Deep null

Deep null

Europe

15 degrees

4 degrees

Excellent low angleradiation

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6 Element 15 Meter Yagion a 48 Foot Boom, 200 Feet High

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Deep null Asia/Pacific

10 degrees

3 degrees

Excellent low angleradiation

0

2

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20

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7 Element 10 Meter Yagion a 48 Foot Boom, 200 Feet High

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Deep null

Deep null

Europe

12 degrees

3 degrees

Excellent low angleradiation

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2

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7 Element 10 Meter Yagion a 48 Foot Boom, 200 Feet High

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Deep null Asia/Pacific

8 degrees

2 degrees

Excellent low angleradiation

Secret #2: Eliminate Radiation Pattern Nulls

Well designed stacked Yagis provide the best of both!- low angle radiation, and- null-free radiation patterns

Tip #2: Use stacked Yagis to produce broad null-free patternsthat cover the full range of needed elevation angles

Stacked Yagis require a tower 70 to 100 feet tall

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Two Stacked 5 Element 20 Meter Yagison 48 Foot Booms, 50 and 100 Feet High

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BOTH

100’

50 FT

Europe

18 degrees

5 degrees

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12 degrees

Two Stacked 5 Element 20 Meter Yagison 48 Foot Booms, 50 and 100 Feet High

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BOTH

100’

50 FT Asia/Pacific

4 degrees

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Two Stacked 6 Element 15 Meter Yagison 48 Foot Booms, 47 and 94 Feet High

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94 FT

47 FT

Europe

15 degrees

4 degrees

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Two Stacked 6 Element 15 Meter Yagison 48 Foot Booms, 47 and 94 Feet High

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94 FT

47 FT Asia/Pacific

10 degrees

3 degrees

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Two Stacked 6 Element 10 Meter Yagison 36 Foot Booms, 35 and 70 Feet High

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70 FT35 FT

Europe

12 degrees

3 degrees

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Two Stacked 6 Element 10 Meter Yagison 36 Foot Booms, 35 and 70 Feet High

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70 FT35 FT Asia/Pacific

8 degrees

2 degrees

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Two Stacked 3 Element 40 Meter Yagison 48 Foot Booms, 100 and 200 Feet High

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200’100 FT

Europe

23 degrees

7 degrees

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Two Stacked 3 Element 40 Meter Yagison 48 Foot Booms, 100 and 200 Feet High

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200’100 FT

16 degrees

5 degrees

Asia/Pacific

Secret #3: Stacks for Europe and Asia are Different!

Stacked Yagis that produce an optimum null-free higher angleradiation pattern for Europe…cannot produce the optimum lower angle pattern for Asia/Pacific

Stacked Yagis that produce an optimum null-free low angleradiation pattern for Asia/Pacific...cannot produce the optimum higher angle pattern for Europe

Secret #3: Stacks for Europe and Asia are Different!

The solution is:

Tip #3: Use switchable stacks of three Yagis to select broadnull-free radiation patterns for either Europe or Asia/Pacific

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Three Stacked 5 Element 20 Meter Yagison 48 Foot Booms; 50, 100, 150 Feet High

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50 FT/100 FT

100 FT/150 FT

Europe

18 degrees

5 degrees

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Three Stacked 5 Element 20 Meter Yagison 48 Foot Booms; 50, 100, 150 Feet High

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50 FT/100 FT

100 FT/150 FT

Asia/Pacific

12 degrees

4 degrees

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Three Stacked 6 Element 15 Meter Yagison 48 Foot Booms; 47, 94 and 140 Feet High

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Europe

15 degrees

4 degrees

47 FT/94 FT

94 FT/140 FT

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Three Stacked 6 Element 15 Meter Yagison 48 Foot Booms; 47, 94 and 140 Feet High

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10 degrees

3 degrees

47 FT/94 FT

94 FT/140 FT

Asia/Pacific

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Three Stacked 6 Element 10 Meter Yagison 36 Foot Booms; 35, 70 and 105 Feet High

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12 degrees

3 degrees

35 FT/70 FT

70 FT/105 FT

Europe

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Three Stacked 6 Element 10 Meter Yagison 36 Foot Booms; 35, 70 and 105 Feet High

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8 degrees

2 degrees

35 FT/70 FT

70 FT/105 FT

Asia/Pacific

Antenna Secrets of the Top Multi-Op Stations

Revealed !

Secret #1: Use All of the Right Angles

Secret #2: Eliminate Radiation Pattern Nulls

Secret #3: Stacks for Europe and Asia are Different!

Tips to Apply to Your Own Station

Tip #1: Design your antennas for as many of the right angles as you can. A good compromise is: 50 - 100 feet for Europe 80 - 100 feet (plus) for Asia/Pacific

Tip #2: Use stacked Yagis to produce broad null-free patternsthat cover the full range of needed elevation anglesStacked Yagis require a tower 70 to 100 feet tall

Tip #3: Use switchable stacks of three Yagis to select broadnull-free radiation patterns for either Europe or Asia/Pacific