radiating RF cable to YAGI not working

[pwc0nne1y]

Hi I am looking for some advice,

I am trying to install a radiating cable from a YAGI feed but I don't seem to be getting any signal? i have connected a spectrum analyser to the furthest end of the Radiating cable and I can see the RF carriers.

could anyone give me some hints to try.

 

[vfone]

What type of radiating cable you have? Coupled mode or radiating mode? Coupled mode cables have wider bandwidth, when Radiating mode cables are optimized for particular bands.
Radiating cables are defined by their coupling loss, which is defined as the difference between the power transmitted into the cable and the power received by a λ/2 dipole antenna located at a distance of 2m from the cable.
Are you using a λ/2 dipole antenna for your tests? Check the coupling loss mentioned in its datasheet.

 

[pwc0nne1y]

What type of radiating cable you have? Coupled mode or radiating mode? Coupled mode cables have wider bandwidth, when Radiating mode cables are optimized for particular bands.
Radiating cables are defined by their coupling loss, which is defined as the difference between the power transmitted into the cable and the power received by a λ/2 dipole antenna located at a distance of 2m from the cable.
Are you using a λ/2 dipole antenna for your tests? Check the coupling loss mentioned in its datasheet.

Hi, thanks for the reply,
The radiating cable i have is times microwave T-RAD-600. I am unable to find anything about modes in the data sheet? I am using a hand held radio for testing at a distance of 2m but I am connecting directly to the cable to see the carriers, am I correct in saying the cable needs a load at the far end?

 

[FvM]

am I correct in saying the cable needs a load at the far end

The coupling loss specification is surely referring to a correctly loaded cable. Standing waves might result in an irregular radiation characteristic otherwise. I would expect to see some radiation with different load though.

My questions: What's test frequency, has the cable sufficient length, is the input power high enough to see radiated signal despite of expected 60 - 80 dB coupling loss?

 

[vfone]

T-RAD cables are using coupled mode, utilizing a continuous single slot in the metalized shield. Is broadband, from about few MHz (AM band) to 2.5GHz.
Here is the datasheet where you can find the coupling loss for various frequencies:

https://timesmicrowave.com/wp-content/uploads/2022/06/radiating-cable-r-catalog.pdf