d-star

[kb2men]

Hi:
I bought in my icom-7100 to analyze the transmissions via DV, and the net on 14.280 was coming up. I thought I'd use the Flex 5000A to do the receive into DSDPlus. After looking at the spectrum, I started playing with the RX modes. I could see the audio being received on DSD's scope, but no decodes. I eventually used SDRPlay and SDRUno in FM narrow, and no de-emphasis which worked. I left the RX filter very narrow, containing only the D-Star bandwidth.
I noticed the RX waveform looked like a clipped triangle wave.
I went back to the Flex and started again playing with the FM RX modes. The RX scope shows a rounded waveform. I seen a 'data' button! This didn't seem to help. I seen the DSP settings for FM-D. It looks like the buffer can be changed for just the digital switch. That didn't seem to help the waveform. I right-clicked the FM Mode which let me choose WFM, I guess way wider than 5KC. The decodes worked, but so many adjacent stations came in with it.
I was wondering if some sort of fine tune on FM bandwidth and maybe even de-emphasis can be implemented, like the sliders on sideband.
Thanks!
Harry KB2MEN

[ke9ns]

The Panafall display of the Flex-5000 is not effected by the mode your running whatsoever.
Literally the only thing that can effect the display is the NB feature... if a very very strong signal is anywhere within the 192khz sample range, it can cause the Noise blanker to display artifacts on clean signals, and cause the audio to pump to the that very very strong signal.

The FM-D turns off the CTCSS tones which occupy the bandwidth directly next to the FM carrier (i.e. center), and turns off the "emphasis / De-emphasis" of both TX and RX. There is 2k, 5k (good for normal ham digital, like APRS, winlink, etc) and WFM which is very wide for non-ham decoding.

You can improve the display of the Panafall with making sure your Audio Sample rate is 192khz and setup->display->Hi-Res Panafall is ON, and I run the FPS at 30 frames a second. Auto wtr/pan is ON, Avg pan move is ON, waterfall avg time is 30msec, update period is 30msec, and Averaging time = 350msec then I make sure the Avg button on the console is toggled to AvgP (so the waterfall is not averaged, but the pan is). You can lower the avg time to make out more detail. I also run the setup->DSP->Options->Buffer size at 4096 for the sharpest RX and TX bandwidth audio.

Darrin