Ferrite Rod Antenna Shielding

[Dave.Auld]

Morning All,

I have completed building the amp and controller and they are working great, just need to build the antenna.

I have the 200mm ferrite rods supplied by Blitzortung and was looking at the various instructions and guides etc. but I'm a little bit confused and hopefully someone with so more knowledge can help this noob.

In the guides it says to try without the shielding first to save some effort, and then also recommends to use ribbon cable to shield PVC conduit if required.

Why not use copper pipe instead on pvc conduit wrapped in ribbon cable, to me that would be the ultimate shield or is it a case of that it would be too thick or is there something else I'm missing?

Alternatively I was planning on using the pvc conduit wrapped in adhesive aluminum foil .

Please can you point me in the right direction before I head off to the local DIY store to pickup the bits I don't have. (I'm fortunate to have outdoor shielded cat5 and shielded rj45 connectors left over from my CCTV install).

Thanks,
Dave

[Eric.Wouters]

Shielding is not always necessary but i finally decided to use them

I shielded with a simple plastic electric tube and as you said adhesive aluminium tape. But don't forget to let a little line parallel to the antenna unshielded or you end with no signal at all (good way to test external interference)

[Dave.Auld]

But don't forget to let a little line parallel to the antenna unshielded or you end with no signal at all (good way to test external interference)

Ok, so I need a space in the shielding running the length of the ferrite rod enclosure?

Does the size of this gap matter? e.g. 1mm 2mm etc.

Does the orientation of the gap matter? e.g. If I'm looking down through the conduit and they are in the horizontal plane, does it need to be at 12, 3, 6, 9 o'clock position, as I am putting these up on my roof, I'm guessing somewhere between 9 through 12 to 3 (i.e. top half) would improve shielding from anything in the house.

[Eric.Wouters]

here is a nice thread with images

[Dave.Auld]

Thanks.

Time to get building!