Using this method I tweaked the Config menu filter offset adjustments for my 500hz and 200hz filters. It seemed to make a difference centering the passband, especially on the narrower filter.
Although my K3 was factory built, I have found that the REF CAL freq, S meter and now filter offsets all needed a bit of tweaking. tnx and 73, Gary W7TEA Bill W4ZV wrote: > > > > Ed Muns, W0YK wrote: >> >> Another method, more laborious, but fairly accurate is to use the >> Elecraft >> XG1 or XG2 to inject a stable signal at the antenna port and deploy the >> dbV >> function in the K3 to measure the amplitude every 10 Hz or so. Plot the >> data manually or by entering into a spreadsheet that produces a graphic >> of >> the IF response. >> > > You only need the two -6 dB points, which can be measured to a resolution > of 1 Hz and 0.1 dB using the internal AFV/dBV function. You should set > AGC Off and ensure WIDTH (i.e. the DSP BW) is >> than the filter you are > measuring...otherwise you're measuring the combination of XFIL plus DSP. > I do this by disabling all filters except the one under test and setting > WIDTH >> XFIL BW. Once you have the two -6 dB points, then you can figure > how much offset to enter so these two points are equidistant about the > center. > > 73, Bill > > -- View this message in context: http://n2.nabble.com/How-do-you-measure-filter-offset-tp733034p787731.html Sent from the [K3] mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
