Getting to grips with profiles and digital modes ?

Andrew O'Brien

I should have this figured out by now, but i still have issues and probably too ****.  With PowerSDR and ye olde Flex 1500 or 3000 I had no difficulties setting a clean digital signal. With SmartSDR and DAX I am missing the obvious, I think. I asked the questions when I received the 6300 a few months ago but have not "got it" yet.  The basic question comes down to why with some of the profiles I have created (in attempts to solve some issues), some digital mode transmissions see a full "level" being indicated in the level/compression area and at the same time a full or good amout of RF Power being transmitted.  While other profiles see a full "level" indicated but ZERO  RF Power generated ? I don't see any settings differences between my various profiles, but some get zero RF and others, plenty.  I wonder what makes that difference.  Also, in trying to improve some profile settings that do actually produce an RF level , I notice I have the Mic Profile set with a "DX" setting.  I figure a NOR setting would be better for digital modes but can't change the "DX position to "NOR. Is there NO way to change a Mic profile once saved, you have to start from scratch?

Andy K3UK

Bill W2PKY

Have you check your low and high cut settings when no RF is indicated?

Al K0VM

If you're using the DIGU/DIGL modes for digital, the Proc is disabled and the setting of the Proc has no function. You should not be using USB/LSB for digital modes.  As Bill pointed out, the TX  high and low cut frequencies MUST include the all of the tones contained in the digital signal.  And of  course, you must have TX enabled on the solice you wish to use for transmit..

AL, K0VM

Bill Hassan - K1SM

Andy... Same problem here. Yesterday  was patting myself on the back for getting fldigi set up and even made a few itty q's. This morning, I fire things up, and I get tones in my headphones, I see sig in the level/comp meter, the 6300 is being keyed, but no RF out. - I read some old posts about re-installing flidigi, Did it, no luck. I also checked DAX and saw TX levels. I'll have to check the lo/hi cut settings later, but I'll be using the other rig for the RR this afternoon. I'll be following this thread.

Andrew O'Brien

I re-checked the LOW cut settings and I think Bill and Al are correct. I had some LOW settings at 1900, I set those to 600 and got RF out.  Thanks for telling me not to worry about the processor settings when using DIGU, I forgot about them being inactive. Today, I am getting some nasty distortion on my transmitted digital signals.  Lowering the TX level in DAX or RF Power level makes no difference.  I may just re-start DAX and see if that helps. 

Dick B

Andy, I have a 6300 and operate  several digital modes.  If you would care to give two specific examples I'll try to duplicate them here.  

Ken - NM9P

1) It is always important to know the audio frequency band that will be transmitted, including modulation sidebands, and set TX LO/HI filter limits accordingly. 2) the first thing to check if you are getting distortion is the audio level in the SSDR TX panel Never let it get into the RED, just like with phone signals. If it is too high, either lower it in your digi program, or in the DAX Control Panel > TX Audio slider. I like to keep it a notch or two below the red. 3) if you are still getting distortion, close and reopen DAX. 4) if that still doesn't clear it up, then check the properties in Windows Sound for each of the DAX streams to make sure that the sampling rate hasn't been corrupted. They should be 48000 16 Bit Stereo (DVD Quality) on both "ends" of the Virtual Audio "cable" or "device" set up for each channel of DAX. Check the DAX TX. audio device first. 5) check for stray RF in the shack entering via antenna cables, Ethernet cables, USB cables, mouse and keyboard cable, speaker lines, etc. often this is band sensitive. And sometimes even varies within a band, depending upon cable length resonances, or resonances of combinations of cable lengths. On the other matter... you can modify a Mic Profile and then save it again. Just go to the "Profiles > Mic Profiles, and save it with the same name, just as you would do with a computer text file. I have a Mic Profile set up for RTTY mode, with appropriate bandwidths. And I have another for DigiU that I use for JT65/JT9 that has a 5 KHz width to pass all the whole JT band. Good luck. Ken - NM9P