New expeditions, new DXCC’s

Wintertime is coming and that’s the time that most expeditions take place.

PG5M Gerben started off in Western Kiribati and Tuvalu. I managed to work him on both Island, on 20m CW. Heard him on a few other bands (30m/15m) but the pile-up was like a wall…

Around the same time FT5GA started on Glorioso Island. I managed to work them on a few bands (12-12-17-20) but not on the lower frequencies. I must say that the jamming by lids is enormous, I never experienced that in my life yet.

After that I worked FO/SP9CYY (French Polynesia) on his way to Austral Island, where I worked him as TX5SPA on 30m.  2 new ones.
And today 3D20CR, Conway reef on 20m SSB.

Altogether not band for 3 weeks DX’ing. In the low bands (40m-160m) results are zero: the 40m beam is to low and my 80/160m vertical has failed up to now.

Experimenting with a 160/80 vertical

Last month I erected a combined vertical for 80/160. On a Spiderbeam-pole (18m) I had made a inv-L for 80m (1/4 lambda, 18m vertical, 22m horizontal slope for 160m), the wire is inside. For 80m the wire was taped on the outside, the last 2m sloping in 45 degrees. Feedpoint was the same (one coax from TX to pole.)

SWR was >>> on both 160 and 80m. So I asked Thomas PA2M to help me with his SWR-measuring tool and after a lot of testing it was clear: this will never work. The interaction between the 2 vertical wires is so big that 80m will never dip in the 3,5 MHz band(best dip was somewhere 5,5 MHz???).

160 m dipps inside the band, bit to high but that is easy to repair. SWR is about 1:3, theory points out that 1:1,5 is the best SWR you can get (with horizontal topline, which is not the case). Measured R is about 25 ohm, so maybe a 1:2 transformation is necessary.

So that made it clear that a brilliant idea failed on trying out. For 80m I have to invent something different.

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One Response

  1. Hi,

    Did you try something else?

    Maybe ground the 160 m wire when going live on the 80 m wire? – or insert another resonating alterating component to bring the 160 m wire lower in frequency?

    I have tried multiple vertical wires 1/4 wl. on same feedpoint without problems.

    Henrik

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