> The finest antenna tuners and switches made today....Bar NONE!
Inside photos would be nice. I don't know why every manufacturer
doesn't do that. Is this tuner built with new parts, surplus parts, or
used parts? It looks sorta surplus, with the big knife switch and all.
Tuners are one of the toughest things to build, that's probably why
there isn't really any ideal tuner. It just depends on what the end
user is doing with the tuner.
For example, with an L network using the component values listed
for that tuner the lowest pure resistance matched on 160 meters is
either 37.7 or 25 ohms, depending on how the input transformer
circuit is configured. A conventional "T" has a much wider
matching range, especially with low impedances. That's why they
are so popular and rare. Unfortunately most T's use small value
capacitors and poor inductors.
As another example, moving the balun to the input does not
improve balance. That is a popular but incorrect myth. I see some
of our handbooks even repeat that myth.
In order to improve balance by moving the balun, the tuner must
have at least two ganged capacitors and two ganged inductors that
are grounded to the chassis at the middle. Even then, it only
improves balance when the load is absolutely perfect. It is actually
better to use a choke balun on the output in almost every other
case, as amazing as that might seem!
73, Tom W8JI
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