[Lowfer] EAR this morning....

[Michael Sapp]

Hi All:  Nice SNR on EAR this morning, I don't recall his signal being quite so bright against the background noise.  Could be just quiet condx, but I did change out two bypass caps on the input side of the MC1496 active mixer in the HD-1420 to see if it would help the performance in the 200kHz and down range. Noise levels were between an occasional -77 peak and an occasional -100 min at the time of capture. Several days of consecutive EAR captures should tell me if changing to the lower reactance Xc values for those bypass caps were worth while....

For those familar with the HD-1420 circuit, I left the original .01uf cap from the LPF to the active mixer input in place, so as to not change the loaded Q of the filter.....


http://i1296.photobucket.com/albums/ag19/wa3tts/ear1215a_zps3e209d8a.jpg

73, Mike wa3tts