G'day, Not many comparisons between 3.19 and 3.25 firmware. I didn't check the manual notch, however, it works but it works in a different way in that it creates a big hole in the audio baseband, look at it working in Spectran. Auto notch takes out an interfering heterodyne down to the audio noise floor (Beta 3r19) without creating the hole. Two different functions.
Because there seems to be two distinct camps, one it works and one it is broken I have now done another set of tests. To try and create some degree of stability in my method I used my XG1 as the signal source. The results are quite interesting. But first without the numbers. It is clear that the audible effectiveness of the auto notch (Beta 3r25) depends greatly on the strength of the signal to be notched. AGC action may be the controlling factor. With an S9 signal (XG1 on 7040kHz) the auto notch indeed seems to be working normally, the tone essentially vanishes, but also the background noise vanishes due to the AGC. If instead of a 50uV signal the 1uV signal is used, with my AGC settings the noise floor doesn't change due to the AGC threshold not being met. In this case when auto notch is activated there is still an audible tone. The essential difference between the Beta's is that with 3r19 in either condition 1uV or 50uV no tone is audible. So, numbers: XG1 - 7040kHz K3 SSB, BW norm factory settings BW 2k7, LO k150, FC 1k5, HI 2k85 AGC F (note, auto notch is N/A with AGC OFF) AGC parameters SLP 005, THR 005 (nothing exotic) I used readings from both the internal K3 dBV metering and from Spectrogram 16. There is a difference. My sound "card" is a pretty bog standard Dell vintage 2000 not a fancy low noise offering. Beta 3r19 Beta 3r25 dBV Gram 16 dBv Gram 16 0 -89 0 -89 Noise floor no signal +17.8 -51 +18.2 -50 1uV signal -1 -92 +2.5 -69 Auto notch Note that with the 1uV signal there is no change in noise floor (0/-89) due to AGC action. 0 -89 0 -89 Noise floor no signal +26.9 -41 +27.4 -41 50uV signal -23.7 -106 -8.5 -108 Auto notch Note that with the 50uV signal noise floor adjacent to the signal has dropped to -23.7/-108 due to AGC action. I hope this has been useful, interesting even. It is clear that something significant has changed between Beta 3r19 and 3r25 and I have elected to stick with Beta 3r19 for now until it's problems are fixed. The enhancements in Beta 3r25 are not a big issue at this QTH. Aditionally, it would be useful if the "delta f" led flashed throughout the data load process, including the big DSP files. Regards, Mike VP8NO ______________________________________________________________ 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
