Tuesday 9 October 2018

New dipoles

Last weekend I adjusted the elevation axis rotor and I can stand and reach the horizontal antenna dipoles very easy from the ground.
During the process I accidentally got stuck in a support wire for a HF vertical while rotating in azimut bending one antenna slightly but it was easy to bend it back again.





















Earlier test dipole I used 4.76mm copper tubing but have now tuned the antenna and bending fixture to 6mm tubing and it seems to work fine.
Tested to mount one dipole with through hole screws and nuts but discovered that the on the backside where the open wire line later goes the extruding bolt and nut was very close to where the feedline later goes.
I need to use inserted rivet nuts on the boom to avoid extruding anything in that direction but I have not been able to test that yet as the wind has increased and I do not want to elevate fully in high winds.



































The time is running out for the first part of ARRL contest so I need to step it up  and make the feedlines any day soon.
I have made the feedline distances yesterday and will try to stack 2 antennas together and measure the matching and if everything is as expected continue with 4 this week.
Decided to go for 200 Ohms feedlines and with 6mm wires the cc is 16mm.

Need to make some support for the feedlines when I drill and thread then in the lathe to avoid bending or braking them while the lathe rotates.
My idea is to use massive 6mm aluminium for the feedline and drill and thread in the end of each piece and then drill through the junction piece and with toothed washer just bolt everything together.
Will try to weather protect each junction with isolating spray.

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