RaDAR – Preparing to work Bouvet island DXpedition

This DXpedition is within reach of South Africa and in particular RaDAR Ops! I’m not a DXer as such but would like to do some chasing on this one.

My usual wire antennas would probably have to be improved upon to ensure success. Antennas that have served me well in the past are the delta loops and I consulted an article that an old friend wrote a few years back. It can be seen at  H5ANX Delta loop antenna

The standard formula, 286 / f in MHz is used to give the loop length in meters. For 20m it would be 20.15m, the same length of wire used for a 40m end fed via an end fed tuner. That means I can use the same wire for a “20m / 10m” delta loop that is capable of being used on 17m / 15m and 12m using a tuner – or just carry two lengths of wire, one for the “20m / 17m / 15m / 12m and 10m” multiband delta and the other for the 40m end fed. The proof of the pudding applies as always, of course!

If the delta loop is fed from a corner via the 4:1 balun the polarization is vertical – nice for DX! The delta loops are also not critical about height either. All these parameters fit in very well with RaDAR!!!

Like the short coax feed from the rig to the end fed tuner, the same short length can be used to feed the 4:1 balun. Dual function hardware in the pack.

This is what I’ll use for Bouvet and of course the 897d at 100W for a little punch. That means I must refit the LDG AT-897 Auto ATU …. it has presently been removed.

Let the games begin!

Some tree deployment options …….

Update 2018-01-31

The 20m full wave deĺta loop – Measured 20.3m and eventually trimmed 600mm. Practically zero SWR across the whole 20m and 10m bands on the 817’s meter!!!

 I was a little concerned about why I needed to trim so much and discovered this excellent PDF on delta’s. See Delta loop presentation

Amazing, the dramatic effect of insulation on the wire!!! I use “Twin flex”.
Hanging the apex of the delta from a tree limb and tying the bottom two corners down with tent pegs allows for tilt if need be for directional gain. Tuner not needed if only used as a dual bander (20m / 10m)  Fantastic!!!

One thought on “RaDAR – Preparing to work Bouvet island DXpedition

  1. Pingback: I good DX Expedition to work =) – Site Title

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