W8IO Antenna Site - Optimized LPDA

The W8IO Antenna Site - Loggi - 144-27A1

(updated 24 Jan 2016)

2 Meter Loggi - Optimized for Extremely High Gain, Clean Radiation Pattern, High G/T and High F/R
This particular Loggi was created and optimized for extremely high gain, a clean radiation pattern with very small sidelobes and a high F/R at 144.1 MHz. The resulting G/T was excellent. The plots are shown below.

Loggi 144-27A Performance

Electrical Performance at 144.1	144-27A1	144-27A2	144-27A3	144-27A4	144-27A5	144-27A6
Directive/Power Gain (dBi)	16.05/15.94	16.65/16.51	16.35/16.24	16.11/16.0	16.19/16.08	16.18/16.07
E-Plane F/R (dB)	38.27	29.32	34.55	35.39	34.98	35.04
H-Plane F/R (dB)	32.68	24.85	28.97	32.41	34.03	33.8
E-Plane 1st Sidelobe (dB)	-20	-17.7	-17.5	-22	-23	-20
H-Plane 1st Sidelobe (dB)	-18	-15.1	-14.8	-18.3	-19	-18
Min/Max VSWR (144-146 MHz)	1.18/1.74	1.02/1.85	1.06/1.78	1.13/1.83	1.11/2.0	1.14/1.96
4 Bay G/T (dB) at 178" (E) x 170" (H) - 4.5m x 4.3m	-1.47	-	-	-1.39	-1.29	-
NEC2 File	144-27A1	144-27A2	144-27A3	144-27A4	144-27A5	144-27A6
4 Bay NEC File	-	-	-	-	144-27A5x4	-

Compare the Electrical Performance to long Yagi beams: VE7BQH Gain table for 144 MHz (DXMaps)

Mechanical Performance:
Boom Length 25.85 feet 7.88 m 3.8 wavelength at 144.1 MHz
Recommended Feed Boom diameters: 1" to 1.25" square (DX Engineering or On-Line Metals)
Recommended element sources: On-Line Metals, McMaster-Carr

LP144-27A1 current diagram

LP144-27A1 VSWR

LP144-27A1 Gain (dBi) and F/B and F/R

LP144-27A1 azimuth pattern at 144.1 MHz

LP144-27A1 elevation pattern at 144.1 MHz

Comments are welcome!

contact Roger: email to

rgcox2 (at) gmail.com

Roger Cox W8IO - Spring Lake, MI