5/6 (11) element 21/28MHz Yagi (11.45m)

Description

An Excellent Dual Band Yagi for 21/28MHz with 10.5m boom

The 21-28-11 Dual Band Yagi has a total of 11 elements, 5 elements are used on 21MHz while 6 elements are used on 28MHz. The 21-28-11 InnovAntennas Dual Band Yagi stands aside from the crowd due to the methods used for its design. No traps or coils and no phasing arrangements are used within this antenna and there is no need for 'compromise' spacing between elements as the antenna has a set of correctly spaced elements for either band but still deploys only one 50 Ohm feed-point. An excellent antenna with great SWR bandwidth and performance in one package.

Performance

Gain on 21MHz: 10.61dBi @ 21.225MHz

F/B on 21MHz: 24.47dB @ 21.225MHz

Gain on 21MHz at 15m above Ground: 15.68dBi

Gain on 28MHz: 10.96dBi @ 28.400MHz

F/B on 28MHz: 25.14dB @ 28.400MHz

Gain on 28MHz at 10m above Ground: 16.04dBi

Power Rating: 5kw+

SWR 21MHz: Below 1.2:1 from 21.00MHz to 21.450MHz

SWR 28MHz: Below 1.4:1 from 28.000MHz to 28.600MHz

Boom Length: 11.456m

Weight: 17.17Kg / 37.84LB

Wind Load: 0.64 Square metres / 6.94 Square ft

Turning Radius: 7.604m / 24.95ft

Wind Survival: 122KPH / 76MPH

Specification

This antenna deploys elements tapering from 3/4 inch (19.05mm)  to 1/2 inch (12.7mm)  for  21MHz with elements starting at 5/8 inch (15.88mm)  tapering through 3/8 inch (9.525mm) for 28MHz . The antenna has fully insulated elements which will ensure continuous, high performance for many years to come. Boom to mast brackets are included with all antennas which will support 2 inch (50mm) masts.  Boom is 1.75 inch square 10SWG aluminum and a Kevlar boom guy is supplied along with Stainless Steel turnbuckles for adjustment.

Our antennas are constructed with the best quality materials in order that the best mechanical construction can be achieved, not the cheapest and most profitable! Even a digital caliper is used to measure the elements during production to help ensure the best possible results when installed.

Note: Much development time has gone into our antennas, not just on basic electromagnetic design, we are able to model the effect of insulators, booms and other objects to ensure the make-up of our antennas has least effect on performance and pattern degradation. More information can be found here

• Marine grade Stainless Steel Fittings
• Original Stauff Insulation clamps
• Mill finished boom and elements for highest levels of accuracy

Azimuth Plot 21MHz

Azimuth Plot 28MHz

Elevation Plot 21MHz (15m above ground)

Elevation Plot 28MHz (15m above ground)

SWR 21MHz

SWR 28MHz

Antenna Layout

Manufactured the right way, not the cheapest way!