AirNav Systems Forum

AirNav Radar => AirNav Radar Discussion => Topic started by: JohnOlanMills on May 31, 2016, 02:06:47 PM

Title: How can you verify that your anntena is working correctly
Post by: JohnOlanMills on May 31, 2016, 02:06:47 PM
Humor me if this question is too obvious for some but I have a sneaking suspicion that my antenna is not working correctly.

It is on a tower clear of any obstacles, no obvious breaks in the line, it is about 30ft in the air so I can't just take it down so easy.

Can I check with a multimember the ohms or shorts, and if so what show they read.

Thanks Guys,

John
Title: Re: How can you verify that your anntena is working correctly
Post by: neroon79 on May 31, 2016, 03:59:48 PM
The Ohm value of coaxial cable e.g. 50 Ohm is the wave resistance or the characteristic impedance of the cable. This value can't be measured with a multimeter.

If the cable isn't faulty, you would measure a high mega ohm or giga ohm resistance between the core lead and the shield lead of the cable, regardless if the antenna is connected or not. If you measure some kilo Ohms or below it is possible, that the cable or one of the connectors is drowned and corroding has started.

More is as far as I know not possible with a DMM.

Ingo
Title: Re: How can you verify that your anntena is working correctly
Post by: James Harris on June 02, 2016, 01:10:59 AM
Quote from: JohnOlanMills on May 31, 2016, 02:06:47 PM
Humor me if this question is too obvious for some but I have a sneaking suspicion that my antenna is not working correctly.

It is on a tower clear of any obstacles, no obvious breaks in the line, it is about 30ft in the air so I can't just take it down so easy.

Can I check with a multimember the ohms or shorts, and if so what show they read.

Thanks Guys,

John

John,

I would contact either [email protected] or [email protected] and they might be able to help you out as well ?

James
Title: Re: How can you verify that your anntena is working correctly
Post by: JohnOlanMills on June 07, 2016, 11:30:50 AM
Yesterday I took a multimeter to check my antenna cable and it shows a dead short, I could only test the end of the cable, I have the antenna on a tower with a tall pole, maybe 30', so I will have to take that one down and replace it.
Title: Re: How can you verify that your anntena is working correctly
Post by: neroon79 on June 07, 2016, 03:37:20 PM
Many thanks for the feedback about your status.

Ingo