Quote:
Originally Posted by dad911
If the pipe really "IS" the antenna, changing the length changes the resonance frequency.
You may want to consult the manufacturer.
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I “mis-spoke”. Technically the two dipoles are the resonant radiating elements. They are mounted to a piece of pipe at a specific distance (1/4 wave in this case), which defines the radiation pattern of the antenna. The elements have their co-ax cables, combined into one cable, running inside the pipe and terminating out the bottom to one connector. The piece of pipe, two elements, co-ax and connectors are manufactured as an "antenna". Clamping onto the lower portion of the antenna in order to mount it does not change the resonance of the antenna system: That is already determined by the two dipoles. Their spacing relative to each other and to the distance from the pipe to which they are affixed determine the radiation pattern. I can mount the “antenna” to any mast if I like. I could even mount it to the side of a tower if I chose to. It would affect the radiation pattern to some degree in that case but not the resonant frequency.
If we forget about the antenna for all intent and purpose, I would like to focus on the applied force to the mast I want to use elevating my “load”. After more research, I believe I’m trying to solve for a “cantilevered” force rather than a bending moment. I have already calculated the cantilevered force, which is expressed in lb-ft (like torque). Now I just need to know whether a particular 8ft pipe say 2” galvanized 18 gauge will stand the calculated force. I can reach out to the manufacturer of the antenna and ask their engineer. I have his name and number. I just thought I would pose the problem here to the “brain trust”.
The documentation is for the landlord. If they accept my documentation then I’m good to go.