7 element 21MHz OP-DES Yagi (17.6m)

A 7 element wideband 21MHz OP-DES (Opposing Phase Driven Element System) Yagi

The OP-DES is the newest in patent technology produced by InnovAntennas and is specifically designed for maximum performance, wide-band HF applications. InnovAntennas use the latest in Electromagnetic Design Technology to ensure the very best results and the OP-DES Yagi is proof of that!

This antenna has a flat SWR curve covering 21.000 - 21.450MHz at 1.1:1 SWR.

Performance

Gain: 12.13dBi @ 21.250MHz

F/B: 32.27dB @ 21.250MHz

Peak Gain: 12.2dBi

Gain at 15m above Ground: 16.87dBi

Peak F/B: 33.83dB

Power Rating: 5kw

SWR: Below 1.1:1 from 21.000MHz to 21.450MHz

Boom Length: 17.6m

Stacking Distance: 10 - 15.5m ( 13m recommended)

2 Stacked Gain @ 13m spacing: 15.05dBi

2 Stacked F/B: 33.82dB

2 Stacked Gain @ 13m Spacing 15m above ground: 19.26dBi

Weight: 35.4Kg / 78LB

Turning Radius: 9.495m / 31.15ft

Wind Loading: 1.02 Square Metres / 11 Square feet

Wind Survival: 160KPH / 100MPH - A 125MPH (HD) version is available upon request

Other options available if higher wind loading/survival is required.

Specification

This antenna is made with 3/4 inch (19.05mm) element sections in the centre of each element, followed by 5/8 inch (15.88mm) and 1/2 inch (12.7mm) outer elements with the OP-DES end sections 3/8 inch (9.525mm). 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 at centre is 3 inches round tube which tapers to 2 inches at each end of the boom. A 'T' bar guy support is supplied along the kevlar guys and stainless steel turnbuckles to guy support adjustment.

OTHER TAPER SCHEDULES ARE AVAILABLE FOR THIS ANTENNA, CALL OR EMAIL FOR DETAILS

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 (with an accuracy of .01mm) to measure the elements during production to ensure they are within 0.2mm of what they should be, ensuring they work as well as our software model predicts.

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 have 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

Elevation Plot

Single 7 element OP-DES up 15m above ground

2 x 7 el OP-DES Yagi 13m apart with the bottom antenna 15m above ground

SWR

A 6el OP-DES

Manufactured the right way, not the cheapest way! 

* Where possible marine grade stainless steel components are used.