Tuesday, May 5, 2009

Phase 3

I made a couple more examples. of audio files. The first is a CW QSO between a VP2 and a FM2 station. The phasing was tuned to notch as much static as possible. The effect is subtle but improves the intelligibility of the weaker station by at least 3 dB. Sometimes 3dB is the difference between go and no go on a weak station. The band noise was running around -114 and the stations were in the -108 range.

40-E

In the next clip I was monitoring a SWBC station well below the noise source.


40-F

You may need headphones but this station is completely covered by noise until the phasing is turned on. The effect is best heard toward the end of the clip when you can just make out the female voice.

Here is a clip of a local broadcast. Bob N4HY wanted to hear this one


40-G

Note the strength of this station -30dBm aka LOUD. The station is completely eliminated, almost like turning on a mute button. The tuning to remove this station is very critical.

I spent some time last night trying to separate WWVB from WWVH on 10mhz. For me the angles between the 2 stations are incident enough that I could not effectively separate the two. This is a job for someone on the west coast. Because WWVH uses a female voice 7.5 seconds before the male voice its easy to tell the two apart.

This feature is way too fun to play with. I find myself spending all my time listening to noise!!!! To what have I devolved???

73