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![]() "Irv Finkleman" napisał w wiadomości ... MFJ, in the MFJ-1625 Manual say.... QUOTE It is always important to have a good RF ground, provided by the counterpoise, when using any whip or long-wire antenna. This is because the MFJ-1623 tuner needs something to "push" against in order to force current into the antenna. If a good RF ground is not available, RF will usually find its way back into the power line (RFI), transmitter audio circuits (RF feedback), or the operator (RF burns). Water pipes provide good dc and ac safety grounds, but they are often inadequate for RF grounding because they are long single conductors. You wrote: " I have a nice role of #18 wire, the end is connected to the tuner, and it is my intention to unroll it along the floor through my suite until such time as it is properly tuned." So it will be: "a long single conductors" RF grounds require large "spread out" surfaces with direct multiple connections to the equipment ground point. Water pipes, heating ducts, or multiple ground rods may work (especially if they are all connected together with jumper wires), but the best RF grounds are radial systems or multi-wire counterpoises. So you should not unroll it but have "all connected together with jumper wires". Jta is the same opinion: "You shouldn't need to unroll the wire at all since you're using a tuner. Just hook it up and tune away." The hook = jumped wire. P.S. In a previous topic where the matter of electrons escaping from the end of the antenna was hotly debated, I'm sure Tesla and Marconi could have used some of my simple practical solutions like this one, and perhaps negated the necessity of long discussions re electrons escaping from antennas. There was also Sir Oliver Lodge. He demonstrated the escaping of electrons from the antinodes (see Fig. 2): He also discovered that HF do not like the long conductors; "The electrical charge stored in the Leyden jars could flow either through the very low dc resistance path provided by the loop of wire or it could flow across the very high resistance path through the air between the spark-gap terminals at B. It would seem that the obvious path for the charge to follow would be through the low resistance wire loop. Surprisingly, Lodge was able to produce very large sparks across the spark-gap, B, even though the dc resistance of the wire across the gap was only a fraction of an ohm.[4]" I am trying to "descend you into the same bottomless pit" S* |
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