Hi Paul Thanks for those thoughts. I see your point re sharing a tri-bander and that looks like a severe case.
Looking at the number of filters already in place and the low spurii expected of Elecraft gear, it looks worth considering to down-grade the extra filters. For instance, the KPA amplifier has low pass filters on its input and output, then the atu has a filtering effect. I wouldn't know what this adds up to, but when the W3NQN filters were designed, things were very different. 73 David G3UNA > On 27 July 2021 at 17:30 Paul GACEK <paul.ga...@me.com> wrote: > > > Hi David > > I think any answer is dependent on the station configuration. > > For example, if the M/2 station is sharing a single tribander (i.e. one on > 20m and another on 15m) then I imagine filters are still essential as a > tri-plexer will only provide so much isolation. > > Another example; If a less than optimal 2xn antenna switch is used (i.e. > doesn’t provide excellent isolation) then filters can help to minimize > interference. > > These observations are based on my limited experience building a portable > SO2R station and separately a short time owning a Flex 6600M that had “state > of the art” internal filters. Reading the Flex manual seemed to suggest that > all bets are off when power exceeds 100w and you want to transmit on one port > and listen on another. > > Paul > W6PNG/M0SNA > www.nomadic.blog > > > On Jul 27, 2021, at 9:09 AM, CUTTER DAVID via Elecraft > > <elecraft@mailman.qth.net> wrote: > > > > Given the improved performance of modern transceivers, is there still a > > call for high specification W3NQN band pass filters in a 2-transmitter > > station? For example on a Multi-2 contest environment. For instance K3S + > > KPA + KAT. The filter fitted between radio and amplifier. > > > > I have the *feeling* that a receive-only filter (with tx bypass) might be > > all that is needed. This is much easier to implement than a full > > transmitter-rated set making fast switching between bands (eg for a quick > > look around) very quick and easy from the keyboard, etc. > > > > David G3UNA ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
