Jim, > There's something different about the K3 Sub-RX, and the Roofing > filters seem to fall apart below about -25dB. Makes a guy wonder > what's going on!
I would bet the subreceiver has excess gain in the IF and you're seeing amplified IF noise (particularly since the bandwidth is about 1 KHz). I don't see any way for the K3 Utility to calibrate main/receiver gain separately (Dick?) but I'd suggest checking the gain calibration of the subreceiver or measuring all of the filters only in the main receiver. 73, ... Joe, W4TV On 7/16/2010 3:28 PM, Jim Brown wrote: > On Fri, 16 Jul 2010 14:38:24 -0400, Guy Olinger K2AV wrote: > >> Each to his own, just don't start a ban the 250 campaign. > > Both you and Ed raise good points. No intent there -- I agree that > the so-called 250 Hz filter is slightly more useful than the 400 > Hz. My real objective is to get Inrad to clean up their act! BUT > -- take a look at the data in this link. Lots of food for thought. > There's something different about the K3 Sub-RX, and the Roofing > filters seem to fall apart below about -25dB. Makes a guy wonder > what's going on! > > http://audiosystemsgroup.com/K3FilterStudy-250HzRoof.pdf > > 73, Jim K9YC > ______________________________________________________________ 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