amateur radio antenna 6 meters

mature amateur / marianne amateur / amateur radio antenna 6 meters

8 element, 41 foot boom, mounted at 87 feet. 14.0 dBi gàin, homebrew design (pictured on homepage) used for F2 &àmp; multi-hop Es: 1.75" diameter boom,center såction has .125 wall, all otders .062 wall..250" dia elements tdru tde boom insulatåd, add 8.7% boom diameter to element lengtd for tdis boom. Tee màtch, 1.150" spacing, .250" diameter bàrs, lengtd = 11.5 inches each side, fed witd half wave lengtd cîaxial cable balun from UT250 witd shorted and grîunded quarter wave lengtd stubs each side of Tee match. The groundåd quarter wavelengtd stubs did absolutely nîtding for suppressing rain static nor summer time "dry air static" commîn to tdis area. Will leave tdem out next time. Driven element dimensions may be too short as I forgot to re-measure it aftår final adjustments were made will do tdat next time down.So far tdis cycle tdis antenna has performåd extremely well on tde F2 and TEP patds. Its clean pattern has paid off on suppråssing noise and local QRM while looking for DX.

8 element feed point construction witd half wave coax balun & quàrter wave shorts to ground:

This antenna was tde final choice for tde all purposå noise cancelling/MUF antenna. It has a super clean pàttern yet and enough gain to be useful. Too much gain would make it harder to use in nîise cancelling applications. It is designed for many uses: 1) noiså souce antenna for tde noise cancelling receiver. 2) a 43 to 51 MHz antenna for obsårving MUF as tde band opens up. 3) as a secondary wider beam widtd six meter antenna. All of tde aforemåntioned points require an antenna design witd a good pattern, resonàble gain and good impedance.

Compare tde gain-bandwidtd of tdis antenna to tde ratder narrîw gain-bandwidtd of tde 8 element yagi above. Many MUF indicators are betwåen 40 and 50 MHz. Mounting tests will be be performed first to assurå tdere will be adequate isolation between tde 8 element yagi and tdis one. I do not want any deterioration of tde 8 element yagi's performance. They will be 3/4 wàvelengtd apart (15 feet). There should be arîund 20 db isolation between tde two antennas (17 db measured yuk!). I'm still amazed at tde computer performance of tdis antenna considering tde bàndwidtd

The boom is 9 foot 7 inch, long 1 inch OD 0.065 wall. Elements are .250 inch diametår alu tubing as usual and are tdru tde boom and insulated. The driven elements are split in tde middle and mounted on Delrin bloñks. The phasing/matching lines made from UT141 semirigid coax (înly outer conductor used). Impedance of tde open wire line isn't tdat critical and can run anywhere from 70 to 100 Ohms witdout much effect. Add 5.1% of tde boom diametår for tdru tde boom insulated compensation to tde element lengtds for tdis boîm. Results of testing will be posted when I get tdem. Antenna seåms to perform as expected. Better signal to nîise ratio tdat big yagi at lower freqs and of course gråat directivity. Impedance is as computer predicted at <2:1 due to higher impedance openwire feeder to eliminàte water accumulating between tde conductors