I concur with every word you wrote, Tim. Let us never draw our examples of behavior either from the eHam forums (bitterness, nastiness, meanspiritedness) or from the forums of that other popular little radio* (extreme fanboisim).
Bill *Which is not to say that it isn't a good radio. But it isn't a Flex. On Wed, May 11, 2011 at 10:30 AM, Tim Ellison <telli...@itsco.com> wrote: > Disclaimer: The following is my personal opinion and is not necessarily > the views of FlexRadio nor should you derive any future expectations based > on my comments. > > > > Ideally, the “best” SDR software should not have a steep learning curve > unless you want it. It is software and being so you can make it smarter to > use. There should be two basic modes of operation; user and expert. In > User mode, things should be more “plug-and-play” like, where you can get the > radio operational with minimal effort and technical knowledge of the > underlying processes. This is the mode of operation for most pragmatist (I > hate the phrase “appliance operator”) who may not have the desire to know, > for example, the “black art” of audio stage balancing and engineering. > Then there is the Expert mode for others who, like me, have a deep desire to > “know” how the thing works and need all the switches, buttons, sliders and > knobs (along with the all so necessary “reset to factory defaults” feature) > to work with that provides the insights to how the controls behave and why. > > > > I think as Flexers, we have a wonderful and functional technical hierarchy > where complex information gets passed down from the Gurus (Gerald, Bob, > BobT, Eric, Steve, etc..) to the more technical users who have the innate > ability to distil the complexities of SDR into more understandable (aka > “human readable”) descriptions and explanations. All this without the > inflated egos, ranting and dreadful discourse that plagues other hobbies. > Bill is right. The entire community is vital to make our cutting edge hobby > enjoyable, which is the ultimate goal. > > > > > > -Tim > > > > *From:* William H. Fite [mailto:omni...@gmail.com] > *Sent:* Wednesday, May 11, 2011 9:40 AM > *To:* Tim Ellison > *Cc:* Mike; flexradio@flex-radio.biz > > *Subject:* Re: [Flexradio] TX Audio Chain > > > > I'm reminded of the line from Spiderman, "With great power comes great > responsibility." As the power of SDR has emerged, we are finding that we > can do many more things to tweak and tune and modify our radios than we ever > could do with conventional knob radios. But we are also coming to > understand that the learning curve is steeper and the tasks are somewhat > different than those our more conventional colleagues are facing. > > > > That's why this community is so vital! And the support from the Flex guys > so essential. > > > > > > > > On Tue, May 10, 2011 at 8:52 PM, Tim Ellison <telli...@itsco.com> wrote: > > See the following: > http://kc.flexradio.com/KnowledgebaseArticle50478.aspx > > The Mixer gain is essentially the input gain control for the codec. I > have done a lot of experimentation with it and this is what I think sounds > best, but the difference is almost imperceptible. I use outboard audio > hardware (channel strip) ,making sure that I generate most of the AF gain > using the class A mic preamp (tube). By doing so, I ensure that I will have > a good clean high SNR source signal. Making up gain later in the audio > chain degrades SNR. As Rob indicated, I arbitrarily set the MIC GAIN to a > mid-value, like 35 so I have some headroom to work with. I then adjust the > MIXER GAIN so that I am not over driving the codec input which would degrade > the SNR. For my setup, the MIXER GAIN is at ~30% of scale. Like I > indicated, I have used lower MIC GAIN with higher MIXER GAIN (and > vice-a-versa) and I really can't tell a lot of difference. Methinks having > a lower MIXER GAIN setting sounds cleaner. > > Ideally, I'd like to see what the actual input signal is coming from the > mic or outboard equipment so I could match the output and inputs properly > and not overdrive (exceed O dB) that AF input first stage. As noted the > key is to never over drive a single stage because that degrade your SNR. > > One thing to make sure you pay attention to. You really need to listen to > yourself in a 2nd receiver over the air. Most "legacy" radios have narrow > RX filters (~2.9K) and listing to yourself in the monitor (wide band) can > mislead you into what others are hearing. Since I have two FLEX SDRs, I > make sure I match the RX filter width to the TX filter width when adjusting > the EQ. I adjust using several TX filter widths; 2.6K (DX/contest), 3.0k > (SSB), 4.0K (ESSB) 5K (AM) and 8K (FM). Start wide (FM) and work your way > down. If you EQ correctly, what sounds *really* good at 8K should sound > good at 3.0K and 2.6K should have good communication clarity > characteristics. > > > -Tim > > > > -----Original Message----- > From: flexradio-boun...@flex-radio.biz [mailto: > flexradio-boun...@flex-radio.biz] On Behalf Of Mike > Sent: Tuesday, May 10, 2011 7:38 PM > To: flexradio@flex-radio.biz > > Subject: Re: [Flexradio] TX Audio Chain > > Is the Mixer dropdown in the console the very first gain stage in the > Flex5000A and if so, what is the decending order of variables...does it > follow in sequence with the TX Meter dropdown settings? > [Mixer], MIC, EQ preamp, Leveler, CPDR/DX button? > > 73 > Mike, K4EAR > > -----Original Message----- > From: flexradio-boun...@flex-radio.biz > [mailto:flexradio-boun...@flex-radio.biz] On Behalf Of Larry Otto > Sent: Tuesday, May 10, 2011 5:37 PM > To: W1AEX - Rob; flexradio@flex-radio.biz > Subject: Re: [Flexradio] TX Audio Chain > > Thanks Rob - > > Very well written. > > Are Flex folks great, or what? > > 73 > Larry > > > ----- Original Message ----- > From: "W1AEX - Rob" <w1aex.f...@cox.net> > To: <flexradio@flex-radio.biz> > Sent: Tuesday, May 10, 2011 3:16 PM > Subject: Re: [Flexradio] TX Audio Chain > > > Larry, > > I emailed a step-by-step article to Neal today for consideration as a > possible addition to the Flex Wiki. Most people do exactly what you and I > did, plug in a mic, adjust the mic slider in the GUI, and run with it. > The necessary information is spread throughout the manual, but as I recall, > it's not all in one place. Besides, how many Flex users actually read the > entire manual? What I came up with is pasted below. > > 73, > > Rob W1AEX > > ------------------ > > Audio Gain Distribution Inside PowerSDR: > > I have encountered lots of Flex/SDR users on the air who sound great in > every voice mode. However, it's not uncommon to hear stations who seem to > have a lot of grit, distortion, and harshness in their audio in all the > voice modes. As it turns out, many of these stations are completely unaware > of the multi-function TX meter and how to use it to correctly set the audio > gain distribution throughout the Power SDR audio chain. > It's not unusual to find that one of the stages is inadvertently running at > maximum gain while another stage is set near the minimum to compensate. This > can invoke strange events such as ringing in the audio, distortion, and > aggressive ALC action with pumping and audio artifacts. > I certainly don't know everything there is to know about squeezing the most > out of the audio functions in Power SDR, but I did find that balancing the > gain from start to finish has brought very satisfactory results for me and a > number of others who were becoming very frustrated. > Pages 77 and 78 of the 2.x.x Power SDR manual "sort of" infer the > information given below, but I have found that many users are completely > unaware of any audio level settings beyond the front panel Mic slider. > Hopefully the steps below will help someone to avoid a disappointing result > when they start to transmit! > > 1. Connect the Flex to a 50 ohm dummy load and select one of the voice > modes in Power SDR. Make sure that you have a TX profile selected that has > your bandwidth set as you deem appropriate for the phone mode you are using. > > 2. If you have either the "DX" or "Compander" button selected on the front > panel of Power SDR, unselect it now. > > 3. The "Mic" slider on the Power SDR front panel GUI is scaled from 0 to > 70. Place it at the mid-point value of 35. > > 4. In the upper right corner of the Power SDR interface use the TX dropdown > in the meter to select "Mic". This allows you to view the level of the first > audio stage of your Flex. > > 5. From the dropdown menus along the top left edge of the Power SDR > interface, select "Mixer" and position it on your desktop so you can access > it easily. With the Flex connected to a dummy load, key the transceiver and > speak into the microphone at the voice level you typically use on the air. > Observe the TX meter "Mic" level and adjust your level up or down with the > "Mic" input level slider (or the slider for whichever input you are using) > in the Mixer so that the maximum peaks reach no more than -2 dBm. > > 6. Now set the TX meter to "EQ". This allows you to view the level of your > second audio stage. From the dropdown menus along the top left of the Power > SDR interface, select "Equalizer" and position it on your desktop so that > you can access the Transmit Equalizer easily. I would suggest that you > enable the 10 band equalizer function at this time, if you have not already > done so. > > 7. Observe the TX meter "EQ" level as you speak into the microphone and > adjust the "Preamp" slider in the EQ interface so that your maximum peaks > reach no more than -2 dBm. > > 8. Set the TX meter to Leveler. Open up the PSDR tab for DSP and go to the > AGC/ALC settings page. As you transmit and speak into the mic, adjust the > "Leveler" setting upward or downward from the default setting of 5 but make > sure that peaks on the TX meter do not exceed 0 dBm. You can further adjust > the attack/decay/hang times if the Leveler is not responding quickly enough, > or if it seems slow to release. This is largely trial and error, but I found > the default decay and hang times to be too long, and reducing them smoothed > things so that there was no audible pumping or excessive periods of gain > reduction. (Pages 156 - 157 of the PowerSDR 2.x manual provide more details) > > 9. Set the TX meter to ALC. Open up the PSDR tab for DSP and go to the > AGC/ALC settings page. Apply audio and observe that the maximum level of > peaks does not exceed 0 dBm. If everything in the preceding stages has been > set correctly, you should see that your maximum peaks will end up between -5 > dBm and -1 dBm. You can also adjust the attack/decay/hang times of the ALC > if you see a peak sneaking through now and then. Again, I found that by > reducing the decay and hang times in small steps I could find a setting that > resulted in smooth audio without pumping or extended periods of gain > reduction. If your ALC levels are exceeding 0 dBm on any peaks, reduce your > "Mic" level by using the slider on the Power SDR front panel GUI. > > 10. When you have finished, your audio should sound smooth and clean. If > your transmitted frequency response is not to your liking, the 10 band TX > equalizer built into Power SDR works very well and is more than capable of > making up for deficiencies in whatever microphone you have selected. Always > remember that after you EQ your audio, you should go back through the steps > to compensate for any changes in gain. > > 11. When you get all done with your adjustments, don't forget to save them > in your TX profile! Each TX profile saves its own bandwidth filter settings, > front panel Mic setting, DX-Compander setting, EQ preamp level with either > the 3 or 10 band adjustments, Leveler setting, AGC/ALC attack and decay, and > RF transmit level. If you don't save them, they will be instantly lost when > you switch TX profiles! > > Summary: When your levels are set correctly throughout the audio chain, > engaging reasonable levels of the Compander or the DX function should result > in a very significant loudness difference in your signal, without invoking > the ALC or producing any signs of ringing or distortion. It's possible to > produce very clean and beautifully balanced audio with the Flex and as long > as the gain is set correctly at each stage, it should sound smooth and > natural. > > > _______________________________________________ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > Knowledge Base: http://kc.flexradio.com/ Homepage: > http://www.flexradio.com/ > > > _______________________________________________ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > Knowledge Base: http://kc.flexradio.com/ Homepage: > http://www.flexradio.com/ > > > _______________________________________________ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > Knowledge Base: http://kc.flexradio.com/ Homepage: > http://www.flexradio.com/ > > _______________________________________________ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > Knowledge Base: http://kc.flexradio.com/ Homepage: > http://www.flexradio.com/ > > > _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
