978 MHZ UAT home brew antenna


#1

Google searches dont give any good results on ground plane or vertical antenna projects for 978 MHz. Any ideas?

Glenn


#2

Just build the coaxial colinear (CoCo) antenna for this frequency. https://www.engr.colostate.edu/~notaros/Papers/Generalized%20CoCo%20Antennas.pdf

coco1


#3

Interesting paper you linked to. There is, in section 4.2 an instance where they describe a CoCo that would approximate the gain of some wire designs. However, I cannot understand how they get to a 33.5 cm element length…their wire examples I presume use a wire with v/c .96 to arrive at a 45 cm element length, they state coax with a .67 v/c yet that would give an element length of 31.85 cm, not the 33.5 cm they use ?


#4

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Use same design as 1090 mhz Cantenna or Spider. The only difference is that whip, radials, and food/drink can height to be 77mm instead of 69mm.

1/4 wavelength at 1090 Mhz = 69mm
1/4 wavelength at 1090 Mhz = 77mm

Above is based on speed of radio signal in vaccum. Since the speed in metal is slightly slower, you may use about 2 ~ 3 mm less than above figures.