Can you give us a typical loss for a tuner matching a G5RV?



"Roy Lewallen" wrote in message
...
Unfortunately, simply counting the number of coils and capacitors isn't
even an approximate way to judge loss. What counts, mainly, is how much
current is flowing in those inductors and how large their wire is (and,
if the capacitors have other than air dielectric, perhaps how much
voltage is across the capacitors)(*). If you do an analysis of a tuner,
you'll find that for a given applied power, the inductor current can
vary a huge amount depending on the load impedance. Consequently, the
loss can vary a greatly.

Lowpass filters are invariably specified when in a circuit with a fixed,
specified impedance load. It's not hard at all to design a lowpass
filter which has low loss under that condition. Likewise, it's not hard
to design a matching network (tuner) which has low loss when the load
isn't too far away from 50 ohms resistive. The trick is to maintain
reasonable loss when the impedance transformation is extreme.

Roy Lewallen, W7EL

Fred W4JLE wrote:
Let's put this an easier way, how many of you have a low pass filter in
line. Most manufacturers claim a .25dB or less insertion loss. These
filters
consist of a boat load of coils and caps.

A tuner normally has 2 varible caps and a single silver plated coil.

While any device indeed has loss, here we are picking fly crap out of
pepper.