Why use the S-Meter for this? Depending on where you are in that S-Unit that can make you miss the center. What you need is a relative dB measurement. Turns out that the only piece of test equipment that you need is a K3.
Center the signal in the passband. Then hit disp and use VFO to get to the AFV menu item. Let it settle on a value and then turn clockwise one more click. You should then see 0dBV. Then as you adjust things you can go up and down until you find the -3.0dBV points of the filter. Or you can test to the two -6dBV points and then calculate the mean of your two points. Just as simple but less error prone. ~Brett (KC7OTG) On Sun, 2010-03-28 at 16:10 +0100, Dave, G4AON wrote: > Inject a clean signal to the K3, around S5 - S7 in level, go into the > CONFIG menu, adjust the filter offset (FLx FRQ) by rotating the main > tuning knob until the signal drops one S point then adjust it to the > other side until it again drops one S point. Set the offset to the > middle of the two extremes. > > My 400 Hz 8 pole filter appeared to have more insertion loss than my 250 > Hz 8 pole, setting the offset solved the apparent additional insertion > loss. My settings are -0.07 for the 400 Hz and -0.05 for the 250 Hz. > > 73 Dave, G4AON > K3/100 #80 > ----------------------- > > How are you testing for offset? Sounds like I should check the offset on my > 5 and 8 pole filters. > > 73, > N2TK, Tony > ______________________________________________________________ > 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 ______________________________________________________________ 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
