Sri for delay - been away.
Rich said:
>Tuners need only a reflectometer to indicate when zero reflected power is
>obtained during adjustment.
Generally speaking, I agree with Rich. However, some tuner circuits can be tuned
up to have a very low input SWR and no output, with the tuner losses being
transformed up to 50 ohms. The result is that the smoke gets let out of the
tuner parts - or the solder out out of the joints! Of course, these tuners can
also be tuned to have a very low input SWR because they're doing the job
correctly.
This effect is more common on the 'match anything anywhere' type design. If you
use the classic link coupled input to a parallel or series tuned balanced
circuit, the effect is less likely. A very cheap indicator is to use a small
lamp - a #47, for example - connected in the feeder. At QRP levels, you need to
short it out because you can't afford the power loss: at QRO, because it will
burn very VERY brightly - but not for long! So connect it across an inch or two
of the open wire feeder. If you want to be really picky, put one in each line
and check they glow equally brightly.
Having an output indicator isn't always necessary, but it's good for a 'comfort
factor'.
73
Peter G3RZP
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