On Sat, 17 Oct 2009 12:37:31 +0100, Dave G4AON <[email protected]> wrote:
>Since obtaining an 8 pole 250 Hz filter to compliment my 8 pole 400 Hz >filter, I have been puzzled as to why the 400 Hz filter appeared to have >more loss than the 250 Hz one (it should be the other way around). >Talking with another K3 owner brought the possibility that the 400 Hz >filter might need an offset, so I fed my signal generator into the K3 >and checked. Adjusting the offset brought up the signal by 1 S-Unit to >match the reading from the 250 Hz filter, I set the offset in the middle >of the two points where the meter dropped. The optimum setting for my >filter is -0.07. > >I think this has been discussed here before (possibly by Tom, N0SS) but >I couldn't find it during a search. > >My 400 Hz filter was supplied with my K3 in Nov 2007, the 250 Hz filter >was new this year. > >73 Dave, G4AON >K3/100 #80 [snip] I found this to be true of my 400Hz and 250Hz filters also. If you also have a sub RX it will help get the two to be exactly together by doing the same to net the filters in the SUB with main. Tom, N5GE [email protected] K3 #806, K3 #1055, PR6, XV144, XV432, KRC2, W1 and other small kits. 2 W2's on order 1 K144XV on order http://www.n5ge.com http://www.swotrc.net ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
