>If you have the bandpass filter between the transceiver and the PA,
>you're driving the PA with the cleanest possible signal. What comes out
>of the PA is (bigger clean signal) + (close-in IMD) + (harmonics)...
>nothing else.
>
>None of these can benefit from a bandpass filter a few MHz wide.
Why can't the bandpass filter knock out the amps harmonics? Surely it
does some benefit. These ICE units are kind of interesting. They use
impedance transformation techniques. Basically, they consist of two
filter sections back to back with a mid-point impedance of about 300
Ohms. This way, they can get better Q because of the higher impedance.
The downside is that RF heating effects are worse. So using this
technique you can get pretty good rejection in a small package. I am not
a filter expert but when ICE explained it to me, it made sense.
73,
Jon
KE9NA
--------------------------------------------------------------------------
The Second Amendment is NOT about duck hunting!
Jon Ogden
jono@enteract.com
www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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