[Boatanchors] OT: antenna couplers?

[jfor at quik.com]

Most VSWR and Transmitted/Reflected power meters are designed for 50 Ohm
systems. The output of an antenna tuner is likely nothing like that and
may well have voltages and currents that will toast a VSWR meter.

The VSWR meter belongs between the transmitter and tuner, in a 50 Ohm line.

Best,
-John

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> Firstly, you didn't say what the antenna configuration was.  That aside, a
> VSWR meter is usually engineered for a particular impedance.  The antenna,
> in this instance being an unknown entity, could be very "reactive"
> inductively or capacitively, since your SWR bridge is giving you a high
> SWR.
> The antenna tuner/matcher is compensating for the reactance, and should be
> used between the transmitter and the antenna tuner.  If you intalled the
> SWR
> meter on the output side of the tuner the SWR would still be high there.
> High VSWR on the feedline will affect losses.  Usually coaxial feeders
> exhibit higher looses with increasing VSWR than open wire or "ladder line"
> type feeders, as the cable/feedline losses are usually less with parallel
> wire feeders.
>
> A lot of other factors come into play.  What type antenna is it? (Dipole,
> end fed wire, off center fed, vertical? some sort of "array" or "beam"?
> Etc.)  What type and length feeder is being used?  With no tuner at what
> frequency or frequencies is the VSWR high? (Over say 3:1)  What is the
> length of the antenna and height above ground?  Is the antenna being used
> on
> more than one band?  Etc.
>
> 73,
>
> Sandy W5TVW