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From: jgibbsfhi@hotmail.com
Date: 07 Mar 2002
Time: 18:49:30
Remote Name: 65.114.21.129
Hi John, name here is Kevin (KB9OWO). I am curious as to how you determined the amount of gain you think you need. 6-dBi is only 3.9 dBd. Thats 3.9 dB over a dipole. If thats all you need then a rhombic is not the solution. A simple 2-element beam can yeild as much as 3 to 5 dB gain over a dipole. For a simple 2-element beam at 30-MHz, the dimensions would be as follows:
For 30-Megahertz:
DIRECTOR = 15.2 Feet long. __________________________________
ELEMENT SPACING = 2.4 Feet. _________________ _________________
DRIVEN ELEMENT = 16.1 Feet long.
This type of beam does not use a gamma match. The elements MUST be insulated from the boom!!!
I write programs in Qbasic to calculate this and much more. If interested, contact me via E-MAIL or via my callsign.
Good luck, 73 DE KB9OWO