Join Date: Aug 2006
Location: Arlington, VA
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Gremlins at work :-)
Could be several explanations. One which does NOT explain this is that somehow the dynaplate is a better RF ground than the steel hull of the boat!
I'd suspect first the connection between the tuner and the hull. The correct way to connect to a steel hull is to use a wide copper strap, clean the protective covering off a small portion of the hull, and bolt the ground strap securely to the hull, then cover it with a protective coating.
It is important to clean the hull section first, since virtually all steel hulls -- mild steel, corten steel, etc. -- have (or should have) protective coverings on both sides.
Another thing to consider is poor connections and surface corrosion. When you changed the ground, you could very well have replaced bad connections with better ones.
I don't really understand your "friend's" logic. Surely the ground plate is attached to the hull which is attached to everything else except the insulated backstay? Even if the ground plate were to be isolated from the hull...which would seem to be impossibly convoluted...they're both sitting in the same medium...saltwater, so the "isolation" wouldn't account for much, would it?
Next, I'd suspect the propagation conditions. They have been pretty horrible lately as we're near the bottom of the sunspot cycle. Occasionally, even in these conditions, there are days or hours during the day when propagation is pretty good -- even excellent. Without a side-by-side simultaneous comparison, it would be impossible to conclude that one is necessarily better than the other.
The importance of this factor (propagation) cannot be overestimated. I'm on the radio everyday, and listening on the HF bands almost all day. For many years. I participate in several nets, including the WaterWay net in the mornings. One day I might be able to hear a station in Charleston with an extremely strong signal. Ten minutes earlier, however, that same station was not copyable. Propagation changes. Chuck, ND7K, runs a LOT of power from his land-based station in the Florida Keys. He has an excellent antenna setup as well. Usually, he's VERY strong. However, sometimes even during the course of the 45-minute net his signal fades to the point of being almost gone completely. Propagation changes. I run 500 watts into an excellent antenna system from my home QTH. Usually I receive very strong signal reports from stations on the Net. But, occasionally, I don't. Propagation changes, from minute-to-minute, hour-to-hour, and day-to-day.
Finally, the 802 is known to be quirky and to have relatively low average power output or "talk power". Gordon West and others have commented on this. The radio usually ships from the factory with the speech compression turned off, and only a technician can turn it on. Thus a combination of propagation conditions, relatively low power output, and timing could well have given the impression that somehow the ground plate is better.
Last edited by btrayfors; 03-17-2008 at 09:52 AM.