the harmonic is 'attenuated' in that the magnitude of it is reduced when the
stub is in line. i look at it like you could replace the stub with a lumped
filter at the same point so the term attenuation makes more sense than
reflections or rejections... i don't really care where the harmonic goes, i
want to know how much it is attenuated by so i can compare with other types
of filters.

"Henry Kolesnik" wrote in message
m...
Dave

Nice site, I like the "white paper" approach as I prefer the info without
the glitter. I've only read a few items and I
quote: "This is a plot of the attenuation provided by the stub. You can
see
that it provides about 32db of attenuation at 28.25Mhz. " I've noticed
that
the literature I've purused indicates that stubs either attenuate or
reject.
None say reflect! I don't want to get into a discussion of word
definitions
becasue reflect and feject are close but attenuate is not in the same
class.
Comments...

--
73
Hank WD5JFR

"Dave" wrote in message
news

"Henry Kolesnik" wrote in message
...
I know that a shorted 1/4 wave stub exhibits a very high impedance.
But
for the 2nd harmonic it's a 1/2 wave stub and exhibits a very low
impedance
or a short. There are claims that this can be used to filter the even
harmonics. Shorts can't diisipate power and must reflect, so how
does
a
stub work?

stubs work very nicely. you can get practical stub information at my
web
site, including how to build a 40m to 15m 3rd harmonic stub filter:
http://www.k1ttt.net/technote/techref.html#filters

as you may have noticed by now you have kicked the proverbial hornets
nest.
reflections are a touchy word in this group, usually attracting the
endless
argument that travels from thread to thread. in time this will
deteriorate
into name calling and endless argument over reflections, interference,
virtual impedances, and a few other topics.