Topband: T-antenna

DAVID CUTHBERT DAVIDNNAN at MSN.COM
Wed Jan 26 09:10:30 EST 2005


Jeff,

the first antenna has a radiation resistance of 10 ohms while the flat top is 8 ohms. What I don't know is what the equivalent ground loss resistance is. I guesstimate 25 ohms. If so, the difference between the two antennas is 0.7 dB. With a 50 ohm ground the difference is 0.8 dB. With a 12.5 ohm ground the difference is 0.6 dB. To me it looks like a wash- I would use the flat top rather than put the inverted-l back up. If one dB or so matters to you (and it does to the big guns) then the inverted-L might be worth the effort. 

    Dave WX7G


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