VR2BrettGraham wrote:
>I believe N6RK has posted in the past his use of latching relays to
>band switch a LF vertical - perhaps close to what PA4N is thinking
>of doing?
>
>Getting power out to a relay like that is pretty easy, but here's an
>alternative...
>
>Two places where I have considered something similar to this is
>switching between 40 & 30m on a linear loaded 40m dipole (by
>shorting across the linear loading sections) & to switch in top loading
>on an HF2V - some sort of home brewed lever switch activated by a
>pull cord.
>
>Much easier to "decouple" the pull cord & in my situation at least,
>the cord could come straight in to the the operating position.
>
>Sometimes the dumbest, inelegant or seemingly ridiculous solution
>might be the best.
>
>73, VR2BrettroGraham
>
>
>
That might work.
The other idea about RF detection, used to trigger a latching relay has
some merit if the relay is used at the right location.
If you use the relay to disconnect the end segment of an antenna, on one
band it will end up at a high impedance point of the antenna. You will
have thousands of volts of RF across the relay contacts. It will
require a huge relay with very good isolation. Not something you would
like to hang in the middle of an antenna wire. (Assuming you could even
find a latching relay like this.)
If you use the relay to short out a coil or loading stub, at a point
that is not at the end of the antenna, you might be able to make it
work, although, this sure seems like a hard way to make a dual band dipole.
Jerry, K4SAV
>
>
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