Rebuilding 15 and 6 meters stubs on Butternut HF9V

 

by ik3umt

 

 

Have you ever seen an HF9V after strong winds action ??

15 and 6 mt wire stubs , originally well tight and parallel to radiator, are overstretched by its bending action so they become slack, loose , when stylus returns to its vertical position.

If, from a functional point of view this can lead to detuning due to close spacing between wire and stylus, aesthetically speaking it has a flabby aspect, surely not deserving for your installation.

It doesnít matter how tight supporting clamps and straps are locked, also with a different mechanical approach they would be bent with traction.

Contextually with groundplane upgrade, Iíve used this solution :

Stubs are no more to be bound or fixed in many points but only connected to the highest clamp.

How to keep conductor tight ?

Using a rigid conductor.

I chose a 2mm diameter stainless steel rod , top locked by mean of a drilled bolt and kept spaced by home made polyethylene spacers.

These ones are 6mm drilled so rod is free to slide without mechanical constraints.

Rod weight keep itself stretched and intrinsic material rigidity both with its flexibility gives always the perfect shape after any bending also.
As rods are not coated (change in velocity factor) they need to be slightly longer than original wires, start about 10-12 inches more to be trimmed for tuning.

Photos give better the idea of solution.

 

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For any doubt or info feel free to contact me at ik3umt@ir3ip.net

 

73 de Federico

Ik3umt