Computer Computations

I have shown a suggested antenna and a sample program for use with Beezely AO program. I have not added computed results, but the set up is there if anybody wants to play with it, criticize it, or whatever. I have made the antenna but have yet to put it up. I will be putting up a 'so so' receive antenna, not for gain measurements but for comparative pattern measurements. (Talk of gain brings out the worst from readers) Pattern measurements will be based on Peter Dodds G3LDO article in the Antenna Compendium, Vol 4. where the receive readings are fed into a computer real time and patters generated in an effort to reduce human error. Computer results using other programs, different loads (capacitor values) would be extremely welcome as would comments regarding approach etc. I will add to the page when results warrant it. (are available)

I might add that i have made many such antennas prior to this one and have found that the multi frequency attributes are there in the real world. This antenna will be used mainly to measure remote changing of radiation patterns for directivity, from front to back, mean steering (multi lobe) and reverse-ability of main lobe (for static or wire beams). Measurements will be corrected from shack to actual antenna measurements so that patterns can be compared with computed forms. Since I am an amateur with no special skills or training in antenna work, one should scrutinize methodology, measurements etc. for errors etc. Help in this direction would be helpful especially if I suggest a new law in nature!

Notes

  • Boom and mounting plates are non conductive.
  • Elements are non tapered. (reduced computer and human error)
  • Feed connections to antenna are modified to reduce computer error for sharp corner joints.
  • Elements made of a large diameter to reduce measurement errors.
  • Non conductive tubing with aluminum foil covering after assembly.
  • Circular ferrite structure added to outside of coax at antenna feed point.
  • Delta feed in same plane as antenna, with coax drop at right angles.
  • Coax feed 3/4 Andrews hard line approximately 200 feet, routed inside of tower and underground.
  • Antenna positioned away from other structures (at distance from transmitter)
  • Capacitors, remote motor driven, linear tubular form as described in earlier pages.

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