Re: SSB Ground

Dave Ritten
 

Hi Joerg I believe that it is hard to improve on a direct connection system using dynaplates. If the connections are good and the dynaplates are relatively clean then I am not sure that extending the ground by adding capacitively coupled (internal foil) or bulk (tanks/engine) will increase performance. A while back I came across an article (which now I can't find!) which was doing a relative test of a KISS counterfoil and other options, they found that a simple connection to a bronze through hole gave very good performance.  I would first be focussing on power to the radio, cabling connections and condition, antenna etc. No doubt you have been through those tests but I attach a useful article that gives some guidelines about trouble shooting marine systems. Having a good SWR meter and a dummy load are invaluable tools in working through a process of elimination. In my experience bad connections due to crimp only PL251 connectors and corroded terminals/cable often is a problem on TX. All PL251 connectors must be soldered. Replacing the ATU/antenna connection and checking that it's routing is clear is also another gotcha. Antennae also fail - try the antenna test in the article. When trying to fine tune a system the biggest issue is measurement - how do you actually know that your system is underperforming when there are so many variables like propagation conditions etc. You have to rely on distant boats to call out what your transmission is like and that is very subjective based on their opinion, location and their receiver etc. I discovered a neat trick recently - there is a global network of enthusiasts who run software defined radios (SDR) that you can connect to over the internet. These SDR's were developed in NZ and known as the kiwisdr. Basically you fire up a browser on your laptop, connect to one of the kiwisdr hosts like https://ve3sun.com/KiwiSDR/  and then you can select an active receiver close to you and tune it to whatever HF frequency you want. You can then listen on your laptop to what that receiver is picking up. You then setup to transmit on that frequency and away you go - you can listen to yourself, as received by that site. This allows you to make incremental changes to your system and see if they make any difference. You can change frequencies and start running really definitive tests. You can change receivers to see how far you can transmit! For example you could attach a temporary strap to your fuel tank and see if that makes a difference, or get a sheet of copper and hang it over the side of the boat. I hope that this helps, at least I am sure that you will find it interesting to play with the kiwisdr network as it is fascinating to listen to what you can pick up on radio receivers scattered around the world.
Best Rgds

   --
Dave Ritten
Auckland
Prospective SM Owner

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