>
>Is there a marketing campaign going on or what ? I did measure ICE,
>Dunestar and W3NQN filter sets on proper (=calibrated) test equipment
>and found that the claimed superiority of W3NQN filters is a hype.
>
>However, placebo effect works here too :))
>
>73, zoli ha1ag
Dear Zoli--
I am sorry to disagree with you in the extreme. I did much of the original
testing (along with K3LR) on the W3NQN filters as well as additional testing
on ICE and Dunestar filters, and the W3NQN filters are DRAMATICALLY better.
Which is what one would expect since the W3NQN filters are top-coupled with
an additional resonant circuit rather than just using a capacitor as
is done in the
ICE and Dunestar filters.
All tests were performed with my HP-4195 Network/Spectrum Analyzer. I have
all of the plots, although, after my move from Colorado, they may be a bit
difficult to find until everything is unpacked.
In addition, I did the power rating testing of each W3NQN design while using
an IC-781 driving an Alpha 87A. Power was set to 200 watts carrier using a
calibrated Bird wattmeter and run key down (continuous carrier) for 30 minutes
into a Bird dummy load.
During initial power testing a couple of the filters ran warmer than
Ed wanted and
new inductors were designed and tested. All of the filters were then re-tested
with 200 watts carrier for 30 minutes into a matched load while the
temperatures
of all components were monitored. Some components ran a bit warm to the
touch, but no components got hot.
It is my opinion and the "opinion" of my test instruments that the
W3NQN filters
are VASTLY superior to the ICE and Dunestar filters in all areas -- pass band
loss, adjacent band rejection, return loss, and power handling. The W3NQN
filters are a superior design using superior components -- all done by the
top filter-guru, W3NQN.
73--John W0UN
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