4 element 21MHz OP-DES Yagi (5.4m)

Availability:in stock 999 item(s)
Product Code:21-DES-4

Product Dimensions and Weight

Product Length: 8.5000M
Product Widtg: 7.1150M
Sales price £439.95
Sales price without tax £366.63

Postage £10.00 to UK mainland (not Scottish Highlands) Europe £20.00,  for rest of World please This email address is being protected from spambots. You need JavaScript enabled to view it.

Prices 20% less for customers outside of EU

altA 4 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. Read more about the OP-DES Yagi Here. 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 1.2:1 SWR.


Gain: 9.01dBi @ 21.250MHz

F/B: 23.59dB @ 21.250MHz

Peak Gain: 9.36dBi

Gain at 15m above Ground: 14.24dBi

Peak F/B: 24.97dB

Power Rating: 5kw

SWR: Below 1.2:1 from 21.000MHz to 21.450MHz

Boom Length: 5.42m

Weight: 9.47Kg / 20.9LB

Turning Radius: 4.476m / 14.6ft

Wind Loading: 0.43 Square Metres / 4.6 Square feet

Wind Survival: 179KPH / 111MPH - (125MPH Version available upon request)

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

Stacking Distance: 6 - 10.5m ( 9m recommended)

2 Stacked Gain @ 9m spacing: 11.89dBi

2 Stacked F/B: 21.02dB

2 Stacked Gain @ 9m Spacing 15m above ground: 16.81dBi


This antenna is made 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 is 1.5 inch square 16SWG aluminum.


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, this ensures 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 4 element OP-DES up 15m above ground


2 x 4el OP-DES Yagi 9m apart with the bottom antenna 15m above ground


The 4el 21MHz OP-DES Element Layout - how the OP-DES Yagi looks




The 4el 21Mhz OP-DES Yagi /P (top)  in Maderia Island (UA9CDC)


Manufactured the right way, not the cheapest way! 

* Where possible marine grade stainless steel components are used