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RW3XA’s 9 Band HF Vertical Antenna

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ANTENTOP- 01- 2005, # 007

RW3XA 9 Band HF Vertical Antenna

 

Recommendations.

  1. With time goes on (a year or a couple of years) I noticed "absence" of the antenna when just switching on the air. But it returns back right after transmitting even with the lowest power out of transceiver. The reason was the oxidation of open silver coated contacts of the relay, though the box is waterproof construction. Replacement by the relay of the same type, but with other coating, reduces probability of this problem by 90 percent but nevertheless it's rare, but happens. Because of this I would recommend to use vacuum relay instead of the open relays, B1B (http://www.nd2x.net/B1B.html ) for example.
  2. Since capacitors are connected to "the hot ends" of the matching network, during transmition there can be rather significant voltages (up to 1KVpp at 100W). I used KVI (http://www.nd2x.net/Russ-caps/cap-en.htm ) doorknob capasitors (pulse type, reactive power is not normalized) 5-10KV. At such power, KVI are stable enough, but at rated voltage can be heated considerably and, accordingly, can make troubles... If power were greater than 100W I would recommend using K15-U (http://www.nd2x.net/Russ-caps/cap-en.htm ) capacitors of proper reactive power.

 

 

P.S.


  Referring to HAMRADIO, any aerial (however transceiver, PA or computer) is only the tool for carrying out QSO. The tool can be effective or not so, Japanese or home-made, etc. (whatever one likes), but it is not the defining factor! These tools can only raise an overall performance of the operator, but not replace it in any way. And even in digital modes RTTY

 

and PSK, I don't mean CW, it's up to the operator, where, when and how, but though uninitiated peoples would think it is all up to computer. And those operators who care only for his gears in the shack, even if it's the best piece of equipment, "are well audible". I mean: I would prefer not hear them at all. So let's improve both the equipment and the qualification of the operator, in fact this harmony is the sense of HAMRADIO! 73!

 

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