Sunday, March 1, 2009

Recording

Here is what the wave screen looks like with the options drop down open



With this screen you can record audio or baseband I/Q off the air, or you can record preprocessed audio or you post processed audio for playback.

Here is a clip of some CW I recorded on 40M this afternoon. I run through a series of filters from 1khz to 500hz to 250hz to 100hz to 50hz to 25hz and then back up the line to 1khz. If you listen you can hear the background noise disappear and the readability improve even with QSB. The station was about -102dBm and the noise at 1khz was also -102dBm with static, with the background noise dropping down to -118 dBm at the smallest bandwidth. His QSB was down to the band noise at times. We were having rain storms when this was recorded and notice how quiet the band sounds even in the face of S-8 static crashes. Also notice there is NO ringing even at the lowest bandwidth. The filters will narrow down to as little as 11hz. I've used that setting only once where it did make a little bit of difference. I usually run 100hz. I can point and shoot 100hz without any problem. The narrower the filter the more expert a shot you have to be, but you can always hit "zero beat" and the radio will center itself perfectly even at the 11hz setting.

CWL40M

The F5K has a means to set up the AGC threshold for a particular band condition and this turns the noise WAY down and improves dramatically the ability to draw intelligibility out of the S/N. It also cuts the fatigue factor way down. With my old Orion, even with all the fancy AGC controls it was a very noisey receiver compared to the Flex. The Orion was quiet compared to the Yaesu FT-1000D. For me just the improvement in fatigue reduction is a huge plus in my enjoyment. I'm a low band kind of guy and I have spent years with my head being filled with static, and its a blessing to get even a little relief from all that, and the F5K gives me a LOT of relief.

The other recording is of yours truly setting up the audio. You can make dozens of adjustments until you get just what you want, and not rely on anyone's "opinion".

LSB75M

This Wave recorder can also record the raw I/Q signal that comes into the computer. If you capture this signal you can play it back through PowrSDR, and you will be able to click around on the screen and tune in different stations etc just as if you were receiving a signal off the air. You could record a pile up for example and fiddle around with the best way to work the pile up to find the tail end or the pattern the DX station is using. It's a unique tool. You will note in the screen above the title is stamped with mode frequency date and time. When I made a bunch of TX files to try and hone my audio it was easy to keep track of the progress from one file to the next.

As I was signing out with Joe K3RR last night a 6Y5 called in to tell me how good my audio sounds. He said he has never heard a bad sounding Flex rig and is interested in the 3K when it comes online. Thinking back I have never heard a bad sounding Flex rig either. Nice audio on SSB Clear crisp non clicky note on CW, and you can watch it all on your bandscope.

You can also download prerecorded files from Flex and down load PowerSDR and use the files for a "test drive" of the software. The quality of the experience is based on how good your computer's sound card is, so it may be excellent or it may be not that great based on your hardware, but you can actually download a test session in the comfort of your own home to get some idea of how the radio works. Amazing!!!

I don't use this recording feature much, I've maybe used it once, so it was kind of fun experimenting with it to get some idea of how powerful it really is. I settled on TX EQ "on" plus compander set to 1. The compander does make a BIG difference in average talk power even set to 1, with virtually no added distortion.

73