FT8 Sessions with Chameleon EMCOMM 3 Base

Hello Operators.
Today we’re discussing the EMCOMM III Base from Chameleon Antenna, but this is not a review. The goal of this video is to let the antenna speak entirely for itself, in a configuration which works well at my home QTH. Another point is not having any more space for an additional antenna on the tower. The ideahere is testing this antenna interactively using using WSJT-X running on a Raspberry Pi. If successful, the EMCOMM III Base will augment the yagis I have on the tower already. What I’m looking for is a Broadband antenna, having reasonable performance, giving me multiple bands on HF, without having to add or remove anything on the tower to integrate it. In this video we go through the SWR, my working configuration, and quite a few FT8 QSOs using the EMCOMM III Base.

The configuration has changed from the original. I’m now using an inverted lazy L configuration, which based on antenna models, shouldn’t work well. I’m willing to tell you the video paints a different picture.

About the video

I think it’s really important to let an antenna or any other piece of gear, speak for itself. That’s why I’m not reviewing this antenna in my video or am I blog. The best and most credible way to present this antenna to you, is simply showing you the results of the tests.


May 2 2018

For several months I’ve had Chameleon EMCOMM III Base antenna, up on the tower, in a sloping configuration. The transformer is at 12m (~40feet) height sloping down to about 1m (3feet) off the ground, NNW ~320° azimuth. The ground lug terminates onto the tower.

I’ve been using the antenna system from my home qth, replacing the terminated dipole (for the moment). HFAPRS, FT8, WinLink, … all with great degrees of success.

SWR is relatively flat across 20m with a 1.3 at the bottom of the band, to 1.6 near the top band edge. So I didn’t use a tuner for this test.

If you’d like to see the entire SWR plot across HF, check out the original post here.

WSPR results were quite astonishing.
nearby stations in Scandinavia came in as expected. European stations were all strong and easy to hear. the oddballs were Japan, Eastern Russia, and South Africa. I’m not quite sure of the path considering my slopers pointing towards North and South America.

  • On day 1, the test started at 2018-05-01 09:06, ending at
    2018-05-01 09:14.
  • Day two started at 2018-04-30 11:28, ending at 2018-04-30 11:48.

The farthest station spotting my beacons was ZS6KN in KG44bj, at a distance of 10,089km (6269,014 miles).
2018-05-01, 09:06, OH8STN, 14.097106, -23, -1, KP25qc 5w
ZS6KN, KG44bj, 10089, 178.

So far so good with the antenna.

73
Julian oh8stn

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