[TenTec] Field day antennas

[Don Jones]

It is hard to debate and discuss typing with one thumb onto a cell phone. At field day we use a tri-plexers to drive a trip band yagis and have found the use of coaxial stubs to be extremely helpful. Long before W2VJN's NCJ article I was doing exactly what he recommended. I use exclusively double 1/4 wavelength shorted stub networks with a 1/6 wavelength coupling cable between the two stubs. 
I have gotten into the practice of fabricating 1/8 & 1/4 wave coax cables 2 each of each type for every stub network. 
A 20 to 30 ft long coax cable is placed between each tri-plexer port and the stub networks. We then add the other cables as needed for our field day deployment. Our standard setup is a 20M stub network on the 20M port of the tri-plexer to prevent 2nd harmonic overload on 10M. On 15M we use a 40M stub network to null 20 & 10 meters. The 40M network will pass 15M with minimal insertion loss. The 10M tri-plexer port is driven directly if the band is open. 
This arrangement has allowed us to use of medium grade radios with dynamic ranges in the 70's to 80's. I myself have had outstanding success using my Omni 6 with the 500hz INRAD filter mod. 
This year for field day we will be using Elecraft KX3's and making a run at 2A qrp from a secret mountain top in EWA. We just scouted the QTH on Friday it has a 3,000 foot drop off to the SE - NE.  You look down to the horizon. We are very excited. This year our callsign will be W7TST 2A EWA. (maybe 3A)
73, Don KO7I


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