Chameleon EMCOMM 3B Ground System.

Hello Operators

Many of you have recently noticed the exceptional performance of my home station, through results shared on social media. Certainly some of you will say the propagation has improved, but that’s not the only truth. I recently added or should I say updated, the grounding system of my primary home antenna.

The Antenna is the Chameleon EMCOMM 3B. It is essentially an endfed random wire antenna. I don’t remember all of this specs in detail, but it’s at least an 80 through 6 meter antenna, and perhaps 160 as well. The reason I use the end fed random wire antenna, is the greater number of set up possibilities afforded to the operator. In my case, rather than having 24 meters of coax cable coming from the top of the tower into the shack, then into my radio, I can bring the transformer closer to the shack, alleviating any coax losses. This isn’t a recommendation, that’s just how I’m doing it. Naturally safe distances need to be observed.

So the first step in this project was sinking a 1.5 meter spike into the ground. I attached a 12awg stranded copper wire, from the ground lug on the Chameleon EMCOMM 3B, to the tip of the spike. This by itself improved the performance of the system with immediate results. I went from barely getting outside Europe, to reaching into the Great Lakes region of the United States and Canada. Seeing the writing on the wall, I started adding quarter wave counterpoise wires to the spike. I added counterpoise wires for 80, 60, 40, 30, and 20 meters. I attached those counterpoise wires to the 1.5 meter spike sunk into the ground. The 20-meter counterpoise was unnecessary. The others were chosen because they are my tactical HF bands.

On the second test, I was reaching out all the way to the west coast of the United States, as well as the East Coast of Australia, and Southeast Asia. I did this comparison using JS8Call, a mode I use daily, so I knew what to expect from it. These were not just plots on a map like wspr, many of these were keyboard to keyboard QSOs. All of my tests took place on 40 meters, using 35 to 50 watts.

The point I’m trying to make here is one every amateur radio operator should know. Even though this is an “end fed” antenna, the addition of a ground spike can improve the performance for transmission and reception of your Chameleon EMCOMM 3B. Perhaps this comment is also true for any end fed antenna system. The bottom line however is, an antenna tuner is no longer required from 80 meters through the SSB portion of 6 meters! Whatever performance is lost through a non-resident antenna, is more than made up for with this level of performance. 160 meters requires a tuner, but this is a small price to pay for the convenience this setup affords me. (No there are no resistors inside the unun).

The images below show rough sketches of the ground system, and how the antenna is actually set up. I’m hoping these sketches will enable you to replicate my results, results which continue to this day.

Thanks to this antenna setup, and the ground system update, I can actually run much less power, while achieving improved results versus pre-update. Now I have excellent coverage of Europe the Middle East and North Africa, running ridiculously low power. I no longer have to wait for Gray Line to get into North America or Australia, those windows are much wider than they were previously. This update has also reduced my already non-existent noise floor, to a level allowing the station to reliably receive messages from low power stations, situated around the world. This is something I couldn’t have done before the ground system update.

To finalize the setup, I’m going to move the apex of the wire, to the 18 meter mark on the tower. An additional 6 meters in the air, should also have a significant impact on station performance. I can’t tell you how stoked I am about this update.

Next I’m going to try to come up with a man portable version of this ground system. Perhaps minus the counterpoise wires or using more of them, but shorter. This way I can deploy the Chameleon EMCOMM 3 Portable, with much greater effect.

73
Julian oh8stn
https://paypal.me/oh8stn/1USD

Spread the love

Be the first to comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.