>One well-known SO2R op commented that he got only 80 watts out
> of the bandpass filters that follow his 100-watt class radios, which
in
> turn means he can not drive his 3-500Z amps to full output.
>
> Is this typical of the bandpass filters available today -- ICE,
Dunestar,
> Array Solutions? Anything to choose among them in this respect, or
others?
>
> Thanks in advance.
>
> 73, Pete N4ZR
> Contesting is!
I don't know about commercial products but the insertion loss of a
filter is function of components losses and design parameters, in other
words the chosen filter configuration, the number of poles and the
desired off band attenuation.
Of course, an alignement that insures good return loss and tuning is
required but I wouldn't trust with the long term stability of a
critical design while a good mechanical strenght and filter capability
to dissipate energy (i.e. when antennas coupling is very tight) is
instead a primary key for reliability.
Basically, if the filter works as required in terms of out band
attenuation and its inherent loss doesn't stress the internal
components, an higher insertion loss is probably a more
acceptable "feature" than a smaller off band attenuation with a filter
with the same number of poles but optimized for a minimal insertion
loss (sometimes required when the filter components aren't oversized
and couldn't dissipate a consistent power).
In my opinion any filter that's less than half dB insertion loss (about
10%) is practically acceptable, if the other goals are obtained and
stable.
73,
Mauri I4JMY
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