found an interesting s-band filter on ebay....
it looks you can use port1 for QO-100 and it needs no retuning maybe other uses are possible (if needed)
it is an DUPLEX filter ...PORT1 is 2410 and below , PORT2 2470 and higher....
ONLY 1 port is need for QO-100 the other can be open or terminated
so maybe other purposes are possible ?
delivery was with measurement datasheet (see attachement) but not verified if ok
an measurement shows an insertion loss of about 1.5dB !! that is a bit to much for use on TX and on higher POWER, if you resolder the other part of the duplexfilter it goes down maybe to 1dB.... SO NOT AS GOOD as HOPED ..!
73 de dg0opk