Experiment: Harnessing The Skin Effect in the Salt Marsh
SCIENTIFIC NOTE TO SELF: Rudy Severns Skin Effect Article
Some of the signal reports being received from Europe at an increasiongly frequent rate (59 +35db, 40 db, 50 dB) appear correlated to high tide levels at Succotash Saltmarsh. Based on my previous experience with the elevated counterpoise system, there is a distinct possibility that the system’s efficiency can be increased by focussing on the ground radial system. Specifically, by increasing its density through (i) addition of radials, (ii) introduction of a perimeter wire connecting the ends of the radials and (iii) elevating the entire radial field to the height needed to cause it to simultaneously submerge to a the depth of one (1) to three (3) inches at median high tides. Tides maximizing below this height cause the elevated system to capcitively couple to the salt water. Tides maximizing above this height cause the radials system to be submerged at a depth greater than that required for The Skin Effect on 7 MHz. The latter is the defaul sceanrio at this time since the ground radial systems are interwoven through marsh grasses, effectuating an elevation above the marsh floor of somewhere between 6" to 12 ". I truly believe elevation fo the ground radial system in this manner will enhance the low-angle performance of the system based on the results of the ground rod vs. radial field A/B tests we conducted a month or so ago.
In those tests we observed stateside stations reporting no difference in signal strength when A/Bing between 4 ground rods and 12 ground radials while DX stations reporting a difference of between 1 to 3 S-units. This suggested that alteration between the two ground systems had no perceivable effect on the higher angle shape of the system’s radiation pattern while having an appreciable effect on its lower elevation slope. This test was repeated several times producing the same results. This would appear to suggest that alteration of near field coupling effectuated by differeing ground systems affects the lower elevation plot of the system’s radiation pattern.
If this is true, then it might well follow that further horsing around with the ground radial system might enhance low angle performance. Of particular interest is achieving near field coupling by means of “The Skin Effect” through such means as to cause the entire surface area of Succotash Saltmarsh to collect return currents transferred to the system through its ground radial system. At present time this “Skin Effect” is likely being exhibited at certain tide levels, as possibly suggested by the increasing signal reports previously mentioned, but has yet to be fully harnessed because the ground radial system is not set up to optimize reception of Skin Effect return currents.
To effectuate this, the ground radial wires should be (i) collectively resonated and then (ii) elevated to a height of two to three feet above the marsh floor. This can be accomplished through the incorporation around its perimeter of wooden ground stakes supporting a wire ring receiving the ends of all elevated counterpoise wires. On 7 MHz, a wire screen can be incorporated by adding a series of concentric wire rings every 8 feet or so (0.1 WL) towards the bases of each vertical. At 40 meter resolutiuon, this elevated ground matrix will behave as a capacitive plate.
More to follow on this...
TS-830s Update: Pronosis Good
Completed the rewinding of the plate choke in the RF cage, using No. 26 enamel wire. This should provide sufficient choking for 40 meters while the correctly sized enamel wire is procured for a permanent fix. Also added a smaller choke in the HV line to replace the one that vaporized. Naturally, a small dab of contact cement was added to the top of the choke to hold the windings tightly in place. New 6146s have been installed. When turned on, and the Heater switch actuated, the finals lit up without any smoke. Will now procede with neutralization before attempting any tuning-up.
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TS-830s RF Cage
Rewound plate choke and installed new 6146s.
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Writer's Studio
This is where I spend most of my time writing The Book.
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