Position rejection from Flightaware

[abcd567]

@thanospapantonopoulo

My antenna is a co-co made from HELIAX 1/4 coax cable

Wow, Heliax is a great cable to make a Coco

 

 

A very successful antenna made by @PeterFairlie using Andrew Heliax LDF1-50

@abcd567

LDF1-50 Antenna
http://ads-b.ca/LDF1-50/super-antenna/

http://ads-b.ca/antenna-collinear-F-CYYZ2/

 

 

@abcd567

the secret of success of Coco made of corrugated sheathed Andrew Heliax coax

When Coco elements are cut to length = VF x 1/2 wavelength:
The phasing element’s (core wire):

• Physical length = VF x 1/2 wavelength
• Electrical length = 1/2 wavelength - OK, optimum.

The radiating element’s (outer surface of the shield):
Physical length = VF x 1/2 wavelength
Electrical length = Physical length = VF x 1/2 wavelength - NOT OK, optimum is 1/2 wavelength.

This can be overcome by using air insulated elements (vf = 1).

Incidently in a currogated sheathed coax, the current on the sheath has to travel along the curved surface of sheath which is a longer path than if the sheath was plain, compensatig for shortfall caused by cutting short by a factor of VF.