Re: [Flexradio] Cw Latency Problem Solved?
Hi Jimmy, We have beaten this horse black and blue on the reflector and the prior Forum over the last three years. This is nothing new for discussion. What is new is that latency has improved and can be improved further. Most of the improvement can come through higher sampling rates (96k and 192k) and proper setup of the sound card and buffers. We intend to publish an application note soon that details how to do the setup and optimization. Faster PCs will help in reducing latency because they will be better able to handle the interrupt load of smaller buffers. This is the identical issue faced in the professional recording industry, which has now moved mostly to PC based systems. Stay tuned for more on this subject from FlexRadio soon. 73, Gerald Gerald Youngblood, K5SDR FlexRadio Systems Ph: 512-535-5266 Fax: 512-233-5143 Email: [EMAIL PROTECTED] Web: www.flex-radio.com > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Jimmy Jones > Sent: Tuesday, May 23, 2006 7:50 PM > To: FlexRadio@flex-radio.biz > Subject: [Flexradio] Cw Latency Problem Solved? > > Thanks Man, > I knew it had to be a serious problem because none of the > gurus ever want to talk about. > "It's better to look good than to feel good." > Monitoring what the circuit is actually doing is the reason I monitor. > I still love the machine though and just can't seem to get > off of it and go back to my kenwood. > How does kenwood do it in the 870? There isn't any noticeable > latency in that rig. That's one monitor circuit that's nearly perfect. > Jimmy > - Original Message - > From: James Courtier-Dutton > To: Frank Brickle > Cc: Jimmy Jones ; FlexRadio@flex-radio.biz > Sent: Tuesday, May 23, 2006 10:24 AM > Subject: Re: [Flexradio] Cw Latency Problem Solved? > > > Frank Brickle wrote: > > If you want to monitor anything passing through the audio > subsystem -- > > note, some sound cards provide a hard bypass, but that's > looping around > > the subsystem -- you can't ever get around a minimum of 1 > buffer latency. > > > > 256 sample buffers / 192000 samples per sec = 1.3 ms latency. > > > > There will probably always be a way to patch signal > around the audio > > subsystem so as to eliminate latency entirely. If you > want to monitor > > what the audio subsystem and signal processing are doing, > however, then > > some latency is always going to be there. > > > > You could provide a secondary digital path through the > host computer > > that used, say, 64 sample buffers. 300 usec isn't bad. > But you don't > > want to use those same 64 sample buffers for your > filters, probably. So > > with minimum latency you won't be actually monitoring the > processing, > > just your input. FireWire systems can likely get the > absolute minimum > > down to around 10 samples. They still won't have passed > through the > > processing in that case either, however. > > > > As long as the audio systems use buffered IO, the latency > will never be > > completely eliminated. As long as you use FFT-based > convolution for > > efficient filtering, the true latency will never be less > than the length > > of the primary filters. > > > > 73 > > Frank > > AB2KT > > > Most sound PCI sound cards use a PCI transaction to > transfer a block of > bytes across the PCI bus. > On most sound cards this is 64bytes. So, with 16bit stereo > output, this > equals 16 samples per PCI transaction. > The sensible values for an application to use are some multiple of > 64bytes for the chunk/period of the entire audio buffer. > For low latency > one would have 2 periods per buffer. > Your 256 samples above seems a sensible enough size for a > period, with > the entire ring buffer being 512 samples. > With a bit of clever tweaking, (i.e. in Linux) one could > pick a 64byte > boundary within the period and start outputting samples, > and they will > reach the speakers, thus not having to wait for the period > to end. It > would be a sort of buffer TX cut in feature. > > The FFT issue has nothing to do with sound card > capabilities, but there > is no reason why the FFT window should have to be in sync with audio > buffer periods. > I don't understand why or if FFT is used for CW TX anyway. > I would have > thought that FFT would only be needed on CW RX. > > James > > > > > -- > No virus found in this incoming m
Re: [Flexradio] Cw Latency Problem Solved?
At 08:24 AM 5/23/2006, James Courtier-Dutton wrote: >F > >The FFT issue has nothing to do with sound card capabilities, but there >is no reason why the FFT window should have to be in sync with audio >buffer periods. >I don't understand why or if FFT is used for CW TX anyway. I would have >thought that FFT would only be needed on CW RX. One does still need to do I/Q balancing on the TX side, and given that the mangitude and phase imbalances are not flat across the band, some sort of frequency domain filtering might be the best way. Or not. There's been some measurements of the Receive side using the onboard impulse generator, but I don't know that comparable measurements have been made on the transmit side. Since the only thing shared between sides is the "digital" local oscillator derived from the DDS, it's not clear that a measurement on the receive side can take out ALL of the imbalance on the transmit side. As Frank has pointed out, for today, we live with the heritage of the dsp chain being half duplex, and using the same buffering strategy for Tx and Rx. Jim ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] Cw Latency Problem Solved?
Thanks Man, I knew it had to be a serious problem because none of the gurus ever want to talk about. "It's better to look good than to feel good." Monitoring what the circuit is actually doing is the reason I monitor. I still love the machine though and just can't seem to get off of it and go back to my kenwood. How does kenwood do it in the 870? There isn't any noticeable latency in that rig. That's one monitor circuit that's nearly perfect. Jimmy - Original Message - From: James Courtier-Dutton To: Frank Brickle Cc: Jimmy Jones ; FlexRadio@flex-radio.biz Sent: Tuesday, May 23, 2006 10:24 AM Subject: Re: [Flexradio] Cw Latency Problem Solved? Frank Brickle wrote: > If you want to monitor anything passing through the audio subsystem -- > note, some sound cards provide a hard bypass, but that's looping around > the subsystem -- you can't ever get around a minimum of 1 buffer latency. > > 256 sample buffers / 192000 samples per sec = 1.3 ms latency. > > There will probably always be a way to patch signal around the audio > subsystem so as to eliminate latency entirely. If you want to monitor > what the audio subsystem and signal processing are doing, however, then > some latency is always going to be there. > > You could provide a secondary digital path through the host computer > that used, say, 64 sample buffers. 300 usec isn't bad. But you don't > want to use those same 64 sample buffers for your filters, probably. So > with minimum latency you won't be actually monitoring the processing, > just your input. FireWire systems can likely get the absolute minimum > down to around 10 samples. They still won't have passed through the > processing in that case either, however. > > As long as the audio systems use buffered IO, the latency will never be > completely eliminated. As long as you use FFT-based convolution for > efficient filtering, the true latency will never be less than the length > of the primary filters. > > 73 > Frank > AB2KT > Most sound PCI sound cards use a PCI transaction to transfer a block of bytes across the PCI bus. On most sound cards this is 64bytes. So, with 16bit stereo output, this equals 16 samples per PCI transaction. The sensible values for an application to use are some multiple of 64bytes for the chunk/period of the entire audio buffer. For low latency one would have 2 periods per buffer. Your 256 samples above seems a sensible enough size for a period, with the entire ring buffer being 512 samples. With a bit of clever tweaking, (i.e. in Linux) one could pick a 64byte boundary within the period and start outputting samples, and they will reach the speakers, thus not having to wait for the period to end. It would be a sort of buffer TX cut in feature. The FFT issue has nothing to do with sound card capabilities, but there is no reason why the FFT window should have to be in sync with audio buffer periods. I don't understand why or if FFT is used for CW TX anyway. I would have thought that FFT would only be needed on CW RX. James -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.392 / Virus Database: 268.7.0/345 - Release Date: 5/22/2006 -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20060523/6cd0d946/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
James Courtier-Dutton wrote: > With a bit of clever tweaking, (i.e. in Linux) one could pick a 64byte > boundary within the period and start outputting samples, and they will > reach the speakers, thus not having to wait for the period to end. It > would be a sort of buffer TX cut in feature. Again, if you have hardware loopback, you can have effectively zero delay. That's not the issue in general. The question is, do you want to monitor input to the radio, or do you want to monitor from someplace within the signal processing chain? If the latter, you have no choice but to go along with the DSP buffering size. > The FFT issue has nothing to do with sound card capabilities, but there > is no reason why the FFT window should have to be in sync with audio > buffer periods. It isn't, even now. > I don't understand why or if FFT is used for CW TX anyway. I would have > thought that FFT would only be needed on CW RX. As presently set up the same DSP buffer configurations are used for RX *and* for generation of the CW signal in the audio passband. That's because the audio subsystem doesn't know from TX or RX. It's just moving sample buffers around. The only way that would change would be to run separate RX and TX processes, which is the way things are headed. For the time being, however, since the SDR-1000 is half-duplex, the DSP software is also. FWIW, the latency issue is somewhat minimized under Linux since the keyer (and CW tone generation) live in a separate process from the DSP, and the sidetone is routed directly to the output without delay, while the actual transmitted tone is routed *through* the DSP. The buffer sizes are still consistent, but the sidetone arrives one buffer earlier than the transmitted CW. 73 Frank AB2KT ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
Frank Brickle wrote: > If you want to monitor anything passing through the audio subsystem -- > note, some sound cards provide a hard bypass, but that's looping around > the subsystem -- you can't ever get around a minimum of 1 buffer latency. > > 256 sample buffers / 192000 samples per sec = 1.3 ms latency. > > There will probably always be a way to patch signal around the audio > subsystem so as to eliminate latency entirely. If you want to monitor > what the audio subsystem and signal processing are doing, however, then > some latency is always going to be there. > > You could provide a secondary digital path through the host computer > that used, say, 64 sample buffers. 300 usec isn't bad. But you don't > want to use those same 64 sample buffers for your filters, probably. So > with minimum latency you won't be actually monitoring the processing, > just your input. FireWire systems can likely get the absolute minimum > down to around 10 samples. They still won't have passed through the > processing in that case either, however. > > As long as the audio systems use buffered IO, the latency will never be > completely eliminated. As long as you use FFT-based convolution for > efficient filtering, the true latency will never be less than the length > of the primary filters. > > 73 > Frank > AB2KT > Most sound PCI sound cards use a PCI transaction to transfer a block of bytes across the PCI bus. On most sound cards this is 64bytes. So, with 16bit stereo output, this equals 16 samples per PCI transaction. The sensible values for an application to use are some multiple of 64bytes for the chunk/period of the entire audio buffer. For low latency one would have 2 periods per buffer. Your 256 samples above seems a sensible enough size for a period, with the entire ring buffer being 512 samples. With a bit of clever tweaking, (i.e. in Linux) one could pick a 64byte boundary within the period and start outputting samples, and they will reach the speakers, thus not having to wait for the period to end. It would be a sort of buffer TX cut in feature. The FFT issue has nothing to do with sound card capabilities, but there is no reason why the FFT window should have to be in sync with audio buffer periods. I don't understand why or if FFT is used for CW TX anyway. I would have thought that FFT would only be needed on CW RX. James ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
As well, if your running with an amp and have the X2-7 delay set too high (long delay), you will in effect, self-flagellate (is that a word?) yourself trying to run high-speed cw with fast break-in. Using either the internal or external keyer with semi-break-in enabled, the first character will be truncated by the amount set in x2-7. This shortening of the first transmitted symbol occurs between the time the radio sets up in transmit-mode and when rf output appears at the antenna port. The more t/r switching occurring, the more noticeable the shortening is at the higher keying speeds (>30 wpm). Now, this is assuming your monitoring via the radio sidetone [MON] and have x2-7 set to some snail-like change-over duration (worst case/stone/age/amp). Typically here, I have x2-7 set to 5ms and its a non-issue running fast break-in. Alternatively, if you are running an external keyer which generates it own side-tone and provides keying compensation, the x2-7 delay becomes completely irrelevant to this discussion. For people forced to run with loong sequencing durations on x2-7, perhaps we could add a first symbol compensation feature to the new-keyer module, Bob? Kirb - VE6IV -- Robert McGwier wrote: > I completely concur. The external keyer, with PTT controlled by the > keyer and internal delay of dot/dash without delay on sidetone and > with PowerSDR semi-breakin turned off, is optimal for this radio. > Thanks to Kirb's input on a bug which was fixed before the last > release, I think we pretty much have this licked. > > Bob > > > > root [knesbitt] wrote: >> Eric, >> this is old news when running the Firebox :-) >> Actually 0-latency operation is not dependent on running at 96 khz. I >> am running my system at 48 khz sampling using the stock Firebox >> firmware and new keyer code (external keyer not required). With the >> PreSonus set to 512 buffers and *2.5ms* latency there is absolutely >> *NO* delay! I can go as low as 2.0 ms latency while running the same >> buffer settings on this system without incurring ANY receive >> artifacts (3.2 Ghz P4-HT). The radio sidetone/monitor is perfectly in >> sync with the keyer sidetone and paddle actuation. >> Saying that however, there are advantages to using an ext keyer to >> more precisely control the break-in action of the radio (for fast >> break-in operation), and first character attack and delay through the >> use of the PTT line. >> >> Kirb - VE6IV >> --- >> >> >> > -- ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
Experience from use of existing radios... The FT1000MP for CW has a bucket brigade delay for CW that can be set to "x" milliseconds between 0 and 30. When the key is hit, if assert transmit state to the amplifier is not already on, it is asserted immediately. The actual CW power is delayed for x milliseconds. The MP has a normal internal delay of several milliseconds from key down to RF out, and the bucket brigade is added to that. The delay is intended to allow time for RX/TX transitions to complete so that there is no hot switching, which can destroy expensive parts in QRO amplifiers. This is not clipped off the beginning of the cw, but smoothly applied to the entire CW transmission after the fashion of an audio delay line. The monitor tone can be either set to the key input, or to the signal as sent, including the x delay. Listening to the signal as sent, with the delay set to 30ms, is for me well into unmanageable because the key closure does produce sound quickly enough. My brain interprets it as malfunction of the paddle and I start pushing it harder to "make it work right". Trying to do 35 wpm with a keyer paddle and that delay sent to 30 is out of the question. This is even though the delay is smooth and uniform. To have that occur *randomly* while trying to send with a paddle, at even half that delay, would be maddening. We had random latency problems in a contest computer like which surfaced after the contest had started. I finally had to shut it down and trouble-shoot it. This even though most of the sent text was computer generated. A local op who heard that signal later said it sounded "like a drunk man was sending." The trouble turned out to be a *latency problem* in the logging program, accidentally introduced with a quick fix of another bug distributed just before the contest. We run with about 6-8 ms total fixed delay of CW text. A little more than needed, but QRO CW contesting is a harsh environment for amps, one where an amp can be run continuously at a 40 percent duty cycle for 48 hours straight. A smooth 5 ms latency mentioned elsewhere, where the assert RX/TX for switching external devices is sent immediately via a hardware bypass, would work. Some irregularity in the disappearance/reappearance of the received signal from the antenna would not be noticed. Irregularity in the audio feedback to the operator from key paddle closure and character formation is maddening. Irregularity in the transmitted characters will be reported by other operators who will question which extremity is being used to send and make snide remarks about apparent blood alcohol levels. 73, Guy. - Original Message - From: "Jim Lux" <[EMAIL PROTECTED]> > > I should think it's more PowerSDR *and* Windows specific. The > processing > chains in PowerSDR (at least as of a couple months ago) assume that > transitions between Tx and Rx occur only on buffer boundaries, so > the > PowerSDR program and the dttsp code included in it are essentially > "half > duplex". Using tiny buffers, fast sample rates, and a fast > computer can > make the latency in the changeover very small. > > Eric's setup has buffers that are about 5 milliseconds long (512 > samples * > 10 microseconds/sample) > > A setup where you have 2048 sample buffers running at 48 ksps will > have > buffers that are about 40 milliseconds long. 40 milliseconds is a > lot of > delay, and if it actually stacks up with two buffers through the > chain, > it's getting up towards the particularly bad delay range around 100 > milliseconds which is particularly annoying (as anyone who has had > poor > echo suppression on a transoceanic phone call can attest to). > > > There is also the fact that the SDR1000 hardware itself is > inherently half > duplex, but the changeover speed for that should be very fast (the > QSD/QSE > should enable/disable in sub-microseconds, and there's probably a > few > tens/hundreds of microseconds to just talk to the parallel port). I > think > there's also a relay, which is the dominant speed limeter. > > The actual management of the audio interface within the Windows > context is > done by another program called portaudio (someone correct me if I'm > wrong > here) which manages the Windows MultiMediaExtensions API calls and > just > shoves/removes buffers into the dttsp input/output queues. > > As you say, there is more than enough hardware horsepower to do full > duplex > with low latency with a much slower processor/data rate. It's the > overall > combination of PowerSDR/dttsp/portaudio/Windows that makes it a > coding > challenge to get full duplex with deterministic delay times. > > And, for what it's worth, I suspect that from a usability standpoint > (not > being a CW op myself, I can only surmise) the important thing is not > low > latency, per se, but a very consistent latency. After all, having > the > speaker 2 feet away introduces a 2 millisecond
Re: [Flexradio] Cw Latency Problem Solved?
I completely concur. The external keyer, with PTT controlled by the keyer and internal delay of dot/dash without delay on sidetone and with PowerSDR semi-breakin turned off, is optimal for this radio. Thanks to Kirb's input on a bug which was fixed before the last release, I think we pretty much have this licked. Bob root [knesbitt] wrote: > Eric, > this is old news when running the Firebox :-) > Actually 0-latency operation is not dependent on running at 96 khz. I am > running my system at 48 khz sampling using the stock Firebox firmware > and new keyer code (external keyer not required). With the PreSonus set > to 512 buffers and *2.5ms* latency there is absolutely *NO* delay! I can > go as low as 2.0 ms latency while running the same buffer settings on > this system without incurring ANY receive artifacts (3.2 Ghz P4-HT). The > radio sidetone/monitor is perfectly in sync with the keyer sidetone and > paddle actuation. > Saying that however, there are advantages to using an ext keyer to more > precisely control the break-in action of the radio (for fast break-in > operation), and first character attack and delay through the use of the > PTT line. > > Kirb - VE6IV > --- > > > -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman Laziness is the number one inspiration for ingenuity. Guilty as charged! ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
If you want to monitor anything passing through the audio subsystem -- note, some sound cards provide a hard bypass, but that's looping around the subsystem -- you can't ever get around a minimum of 1 buffer latency. 256 sample buffers / 192000 samples per sec = 1.3 ms latency. There will probably always be a way to patch signal around the audio subsystem so as to eliminate latency entirely. If you want to monitor what the audio subsystem and signal processing are doing, however, then some latency is always going to be there. You could provide a secondary digital path through the host computer that used, say, 64 sample buffers. 300 usec isn't bad. But you don't want to use those same 64 sample buffers for your filters, probably. So with minimum latency you won't be actually monitoring the processing, just your input. FireWire systems can likely get the absolute minimum down to around 10 samples. They still won't have passed through the processing in that case either, however. As long as the audio systems use buffered IO, the latency will never be completely eliminated. As long as you use FFT-based convolution for efficient filtering, the true latency will never be less than the length of the primary filters. 73 Frank AB2KT Jimmy Jones wrote: > Ya Ya > > I'm able to setup everything for speed as far as I can tell and the ssb > monitor is still terrible. > > Firebox @ 1.5ms > Firbox CPU on High > Audio and dsp set at 256 > and the program runs in realtime mode. > There are no skips on transmit or recieve. > I know a few people that wont buy the flex just because of that. What a shame. > I guess there will be a few cw geeks...uh freaks that won't buy the radio for > the same reasons.(latency) > From: Frank Brickle > To: FlexRadio@flex-radio.biz > Sent: Sunday, May 21, 2006 10:28 PM > Subject: Re: [Flexradio] Cw Latency Problem Solved? > > > Jimmy Jones wrote: > > I wish some of brain - o's could solve the monitor latency problem. > > Well, according to Science Today magazine this week, some string > theorists are speculating that time travel may actually be feasible. > > With that solved the monitor latency problem won't be far behind. Till > then, unfortunately, the only other solution is ESP. > > 73 > Frank > AB2KT > > ___ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.392 / Virus Database: 268.6.1/344 - Release Date: 5/19/2006 > > -- next part -- > An HTML attachment was scrubbed... > URL: > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20060522/78089863/attachment.html > ___ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > > ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] Cw Latency Problem Solved?
Ya Ya I'm able to setup everything for speed as far as I can tell and the ssb monitor is still terrible. Firebox @ 1.5ms Firbox CPU on High Audio and dsp set at 256 and the program runs in realtime mode. There are no skips on transmit or recieve. I know a few people that wont buy the flex just because of that. What a shame. I guess there will be a few cw geeks...uh freaks that won't buy the radio for the same reasons.(latency) From: Frank Brickle To: FlexRadio@flex-radio.biz Sent: Sunday, May 21, 2006 10:28 PM Subject: Re: [Flexradio] Cw Latency Problem Solved? Jimmy Jones wrote: > I wish some of brain - o's could solve the monitor latency problem. Well, according to Science Today magazine this week, some string theorists are speculating that time travel may actually be feasible. With that solved the monitor latency problem won't be far behind. Till then, unfortunately, the only other solution is ESP. 73 Frank AB2KT ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.392 / Virus Database: 268.6.1/344 - Release Date: 5/19/2006 -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20060522/78089863/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
Alberto I2PHD wrote: > James Courtier-Dutton wrote: >> Just out of curiosity, what is the real reason for the latency? >> I use Linux, and users can get high quality, reliable 2ms latency on a >> very modest PC. That 2ms latency is with a Linux application called >> Ardour, that users use for real time audio capture, effects and >> playback. The same latency should be able to be achieved with any Linux >> application. >> > I know almost nothing about Linux, but a friend of mine who does, once told > me that the Linux kernel has some long paths > in the disk I/O management area that run with interrupts disabled. I wonder > how this could allow to have a "guarantee" > of 2ms latency. But, as said, my knowledge of Linux is nil. > > 73 Alberto I2PHD > One has to be careful in order to get the 2ms latency. For example use "ck" kernels. These are latency tuned kernels that remove "the long paths in the disk I/O management" that you mention. "ck" kernels also place some restrictions on which modules one can load, so the "ck" just don't include the modules that adversely influence latency. For example, use ext2/ext3 and not reiserfs. Low latency has trade offs though. In order to get low latency, one has to slightly reduce the overall CPU and I/O processing power of the system as a whole. E.g. One gets the low latency, but it will take just slightly longer to compile a kernel. James ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] Cw Latency Problem Solved?
Eric, this is old news when running the Firebox :-) Actually 0-latency operation is not dependent on running at 96 khz. I am running my system at 48 khz sampling using the stock Firebox firmware and new keyer code (external keyer not required). With the PreSonus set to 512 buffers and *2.5ms* latency there is absolutely *NO* delay! I can go as low as 2.0 ms latency while running the same buffer settings on this system without incurring ANY receive artifacts (3.2 Ghz P4-HT). The radio sidetone/monitor is perfectly in sync with the keyer sidetone and paddle actuation. Saying that however, there are advantages to using an ext keyer to more precisely control the break-in action of the radio (for fast break-in operation), and first character attack and delay through the use of the PTT line. Kirb - VE6IV --- Eric Wachsmann wrote: > > Let me give you the skinny right from the horses mouth. Here's what I did: I was using a laptop (P4 ~2GHz) with a >FireBox. I set the FireBox to 6ms on the FireBox control panel. This could probably go lower on a more powerful >machine. I then set the PowerSDR buffers to 512 for the Audio and DSP. I set the FireBox and PowerSDR to use >96kHz sampling rate. At this speed, our prospective customer was able to send 50WPM using the soundcard >monitor (not an external keyer). This is the first time that we have tried this experiment at high speed since we >added 96kHz support. Previous attempts at this speed all led to us directing our customers to use external keyers >for high speed CW. The long and short of this is that with the right setup (small buffers, low latency, fast PC, etc), >high speed semi-break in CW is possible with the SDR-1000 TODAY! > > >Eric Wachsmann FlexRadio Systems -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20060522/a3b0e02c/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
At 02:03 PM 5/22/2006, James Courtier-Dutton wrote: >Eric Wachsmann - FlexRadio wrote: > > Let me give you the skinny right from the horses mouth. Here's what I > > did: > > > > Eric Wachsmann > > FlexRadio Systems > > > >Just out of curiosity, what is the real reason for the latency? >I use Linux, and users can get high quality, reliable 2ms latency on a >very modest PC. That 2ms latency is with a Linux application called >Ardour, that users use for real time audio capture, effects and >playback. The same latency should be able to be achieved with any Linux >application. > >So, is this latency problem windows specific? I should think it's more PowerSDR *and* Windows specific. The processing chains in PowerSDR (at least as of a couple months ago) assume that transitions between Tx and Rx occur only on buffer boundaries, so the PowerSDR program and the dttsp code included in it are essentially "half duplex". Using tiny buffers, fast sample rates, and a fast computer can make the latency in the changeover very small. Eric's setup has buffers that are about 5 milliseconds long (512 samples * 10 microseconds/sample) A setup where you have 2048 sample buffers running at 48 ksps will have buffers that are about 40 milliseconds long. 40 milliseconds is a lot of delay, and if it actually stacks up with two buffers through the chain, it's getting up towards the particularly bad delay range around 100 milliseconds which is particularly annoying (as anyone who has had poor echo suppression on a transoceanic phone call can attest to). There is also the fact that the SDR1000 hardware itself is inherently half duplex, but the changeover speed for that should be very fast (the QSD/QSE should enable/disable in sub-microseconds, and there's probably a few tens/hundreds of microseconds to just talk to the parallel port). I think there's also a relay, which is the dominant speed limeter. The actual management of the audio interface within the Windows context is done by another program called portaudio (someone correct me if I'm wrong here) which manages the Windows MultiMediaExtensions API calls and just shoves/removes buffers into the dttsp input/output queues. As you say, there is more than enough hardware horsepower to do full duplex with low latency with a much slower processor/data rate. It's the overall combination of PowerSDR/dttsp/portaudio/Windows that makes it a coding challenge to get full duplex with deterministic delay times. And, for what it's worth, I suspect that from a usability standpoint (not being a CW op myself, I can only surmise) the important thing is not low latency, per se, but a very consistent latency. After all, having the speaker 2 feet away introduces a 2 millisecond delay. It's that rhythm thing that's important, and that's very sensitive to random changes in latencies. I suspect that most ops could handle a fixed 50 or more millisecond delay, if it was truly fixed. The problem in the PowerSDR software is that the changeover occurs on buffer boundaries, regardless of when you actually stop sending, so there's essentially a random delay of somewhere between one buffer and two buffer lengths introduced (depending on the relative phase of your QSO back and forth and the buffers going in and out of the dsp chain). It's like trying to play a musical instrument in a band where the drummer can't keep time. (50 milliseconds is about like a 1/32nd note at 120 beats/minute) Jim ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
James Courtier-Dutton wrote: > > Just out of curiosity, what is the real reason for the latency? > I use Linux, and users can get high quality, reliable 2ms latency on a > very modest PC. That 2ms latency is with a Linux application called > Ardour, that users use for real time audio capture, effects and > playback. The same latency should be able to be achieved with any Linux > application. > I know almost nothing about Linux, but a friend of mine who does, once told me that the Linux kernel has some long paths in the disk I/O management area that run with interrupts disabled. I wonder how this could allow to have a "guarantee" of 2ms latency. But, as said, my knowledge of Linux is nil. 73 Alberto I2PHD ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
Eric Wachsmann - FlexRadio wrote: > Let me give you the skinny right from the horses mouth. Here's what I > did: > > I was using a laptop (P4 ~2GHz) with a FireBox. I set the FireBox to > 6ms on the FireBox control panel. This could probably go lower on a > more powerful machine. I then set the PowerSDR buffers to 512 for the > Audio and DSP. I set the FireBox and PowerSDR to use 96kHz sampling > rate. At this speed, our prospective customer was able to send 50WPM > using the soundcard monitor (not an external keyer). > > This is the first time that we have tried this experiment at high speed > since we added 96kHz support. Previous attempts at this speed all led > to us directing our customers to use external keyers for high speed CW. > The long and short of this is that with the right setup (small buffers, > low latency, fast PC, etc), high speed semi-break in CW is possible with > the SDR-1000 TODAY! > > > Eric Wachsmann > FlexRadio Systems > Just out of curiosity, what is the real reason for the latency? I use Linux, and users can get high quality, reliable 2ms latency on a very modest PC. That 2ms latency is with a Linux application called Ardour, that users use for real time audio capture, effects and playback. The same latency should be able to be achieved with any Linux application. So, is this latency problem windows specific? Kind Regards James ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
Let me give you the skinny right from the horses mouth. Here's what I did: I was using a laptop (P4 ~2GHz) with a FireBox. I set the FireBox to 6ms on the FireBox control panel. This could probably go lower on a more powerful machine. I then set the PowerSDR buffers to 512 for the Audio and DSP. I set the FireBox and PowerSDR to use 96kHz sampling rate. At this speed, our prospective customer was able to send 50WPM using the soundcard monitor (not an external keyer). This is the first time that we have tried this experiment at high speed since we added 96kHz support. Previous attempts at this speed all led to us directing our customers to use external keyers for high speed CW. The long and short of this is that with the right setup (small buffers, low latency, fast PC, etc), high speed semi-break in CW is possible with the SDR-1000 TODAY! Eric Wachsmann FlexRadio Systems > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > radio.biz] On Behalf Of Toby Pennington > Sent: Sunday, May 21, 2006 2:02 PM > To: Flex > Cc: Ron Hinton > Subject: [Flexradio] Cw Latency Problem Solved? > > I was just told by someone that Gerald made the comment on Teamspeak last > night that the cw latency problem had been solved. Someone is already > able to send cw at 60 wpm QSK with no latency and has found a way to do > this. > > Does anyone else know about this and in particular how is this > achieved. by a software change or hardware addition. Also does anyone > know about the timeline for this improvement to the SDR 1K. > > Toby W4CAK > -- next part -- > An HTML attachment was scrubbed... > URL: http://mail.flex-radio.biz/pipermail/flexradio_flex- > radio.biz/attachments/20060521/d293d1ed/attachment.html > ___ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex- > radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
Let me qualify that by saying there is no latency in the monitor audio when you use and external keyer. What goes out over the air is still a few milliseconds behind what you hear. It's also worth noting that the truth is that the SDR-1000 is not (and never will be without hardware changes) a QSK radio. Having said that, it can make one darn good semi break in rig. :) Eric Wachsmann FlexRadio Systems > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > radio.biz] On Behalf Of Gerald Youngblood > Sent: Monday, May 22, 2006 11:06 AM > To: 'N3EVL'; 'Ken N9VV'; 'Christopher T. Day' > Cc: 'Ron Hinton'; 'Flex' > Subject: Re: [Flexradio] Cw Latency Problem Solved? > --snip-- > > Let me reiterate that there is NO latency today on CW when you use an > external keyer with built in monitor. > > 73, > Gerald > > Gerald Youngblood, K5SDR > FlexRadio Systems //www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
Hello Flexers, Let me clarify. Eric1 set up our laptop demo in the Dayton booth for NA9F, who sent at up to 50 WPM per his email to me this morning. Eric set the Firebox to 96 KHz sampling and 6 ms latency. The report from Ron was that he "noticed some latency but not a showstopper for me." Running this configuration on a high performance desktop should give better results than the laptop demo did. With 192 KHz sound cards, latency will be cut in half again. PowerSDR software already supports 192 KHz sampling rates. We expect to qualify sound cards or sound card replacements such as "Janus" over the coming months that will support 192 KHz. Further, FlexRadio may choose to manufacture and market Janus or its equivalent as an add on option for the SDR-1000. Janus is essentially conceived to be a high performance sound card with a built in keyer. Let me reiterate that there is NO latency today on CW when you use an external keyer with built in monitor. 73, Gerald Gerald Youngblood, K5SDR FlexRadio Systems Ph: 512-535-5266 Fax: 512-233-5143 Email: [EMAIL PROTECTED] Web: www.flex-radio.com > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of N3EVL > Sent: Sunday, May 21, 2006 6:47 PM > To: 'Ken N9VV'; 'Christopher T. Day' > Cc: 'Flex'; 'Ron Hinton' > Subject: Re: [Flexradio] Cw Latency Problem Solved? > > I seem to remember mention of a solution found right there at > Dayton - some tweak to the soundcard config, perhaps, > resulting in successful semi-breakin capability at speeds > around 60wpm, but not full QSK. I guess we need Bob or > Gerald to spell out the details. > > Pete > > > -Original Message- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Ken N9VV > > Sent: Sunday, May 21, 2006 11:15 PM > > To: Christopher T. Day > > Cc: Ron Hinton; Flex > > Subject: Re: [Flexradio] Cw Latency Problem Solved? > > > > I have listened to that part of the recording again today (now on > > teamspeak) and he clearly said that "the current problem and > > limitation is the SOUNDCARD and not the SDR-1000 hardware". > > So I guess that means that the HPSDR Janus board is a LIFE > SAVER and > > may mean some super CW performance from the current SDR-1000 hw? > > bk de ken > > > > > > Christopher T. Day wrote: > > > Toby, > > > > > > I'm not certain, but I suspect this was a comment about the > > SDR-X, not > > > the SDR-1000. I doubt that there is a simple full-QSK > solution with > > > the latter given its half-duplex design. > > > > > > > > > Chris - AE6VK > > > > > > > > > -Original Message- > > > From: Toby Pennington [mailto:[EMAIL PROTECTED] > > > Sent: Sunday, May 21, 2006 12:02 PM > > > To: Flex > > > Cc: Ron Hinton > > > Subject: [Flexradio] Cw Latency Problem Solved? > > > > > > I was just told by someone that Gerald made the comment on > > Teamspeak > > > last night that the cw latency problem had been solved. > Someone is > > > already able to send cw at 60 wpm QSK with no latency and > > has found a > > > way to do this. > > > > > > Does anyone else know about this and in particular how is this > > > achieved. by a software change or hardware addition. > Also does > > > anyone know about the timeline for this improvement to the > > SDR 1K. > > > > > > Toby W4CAK > > > -- next part -- An HTML attachment was > > > scrubbed... > > > URL: > > > > > > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachme > > > nt > > > s/20060521/d293d1ed/attachment.html > > > ___ > > > FlexRadio mailing list > > > FlexRadio@flex-radio.biz > > > > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > > > Archive Link: > > > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > > > FlexRadio Homepage: http://www.flex-radio.com > > > > > > > > > ___ > > > FlexRadio mailing list > > > FlexRadio@flex-radio.biz > > > > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > > > Archive Link: > > > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > > > FlexRadio Homepage: http://www.flex-radio.com > &
Re: [Flexradio] Cw Latency Problem Solved?
Jimmy Jones wrote: > I wish some of brain - o's could solve the monitor latency problem. Well, according to Science Today magazine this week, some string theorists are speculating that time travel may actually be feasible. With that solved the monitor latency problem won't be far behind. Till then, unfortunately, the only other solution is ESP. 73 Frank AB2KT ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
I wish some of brain - o's could solve the monitor latency problem. - Original Message - From: Christopher T. Day To: Toby Pennington ; Flex Cc: Ron Hinton Sent: Sunday, May 21, 2006 4:42 PM Subject: Re: [Flexradio] Cw Latency Problem Solved? Toby, I'm not certain, but I suspect this was a comment about the SDR-X, not the SDR-1000. I doubt that there is a simple full-QSK solution with the latter given its half-duplex design. Chris - AE6VK -Original Message- From: Toby Pennington [mailto:[EMAIL PROTECTED] Sent: Sunday, May 21, 2006 12:02 PM To: Flex Cc: Ron Hinton Subject: [Flexradio] Cw Latency Problem Solved? I was just told by someone that Gerald made the comment on Teamspeak last night that the cw latency problem had been solved. Someone is already able to send cw at 60 wpm QSK with no latency and has found a way to do this. Does anyone else know about this and in particular how is this achieved. by a software change or hardware addition. Also does anyone know about the timeline for this improvement to the SDR 1K. Toby W4CAK -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachment s/20060521/d293d1ed/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.392 / Virus Database: 268.6.1/344 - Release Date: 5/19/2006 -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20060521/90899f18/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] CW Latency Problem Solved?
Is the Firefox card on the approved lost to enable warranty guarantees? Or are you talking about the Firebox Firewire which is approved? Toby - Original Message - From: "Mel Whitten" <[EMAIL PROTECTED]> To: "Toby Pennington" <[EMAIL PROTECTED]> Sent: Sunday, May 21, 2006 7:03 PM Subject: Re: [Flexradio] Cw Latency Problem Solved? > HI Tony > I was there when the "annoucement" was made. Seems they (not sure besides > Eric who found this out) were able to remove the latency in the Firefox > Soundcard by make some adjustment the card has available. I dont own the > card, but that is "all they did" becuase Bob N4HY says the latency problem > had already been confirmed was caused by the sound card, not the PC/sdr > console. So if you have a Firefox card (evidently this is the only card > that this adjustment can be made on) then this may be the answer. You may > want to "get more info on this" to confirm what I am saying. :-) > Mel > k0pfx > -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20060521/c459d4e8/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
At 08:15 PM 5/21/2006, Ken N9VV wrote: >I have listened to that part of the recording again today (now on >teamspeak) and he clearly said that "the current problem and >limitation is the SOUNDCARD and not the SDR-1000 hardware". This is incorrect. Many, many high performance gaming applications run on the Windows platform and achieve sub=millisecond timing. There are also realtime conferencing type applications that run in the Windows environment with full duplex audio processing. For that matter, successfully playing high rate streaming video/audio requires careful alignment of the streams. It's more a matter of the huge software development effort required to do this within the Windows framework. Devoting a work-year of effort ($100K-250K) to learning to effectively work in the Windows environment may be a reasonable matter to a game developer expecting million unit sales or to a high end video conferencing application developer. However, that scale of labor is not generally available to the folks at Flex. I would imagine that, by and large, the PowerSDR development folk are not Windows multimedia extension devotees, nor do they wish to devote their lives to such an activity. In fact, PowerSDR depends on portaudio to encapsulate and hide most of the mm ickyness, and it would appear that the portaudio developers aren't interested in this either. Or, if some ham who also happens to be a game developer gets interested, we could be in luck. > So I >guess that means that the HPSDR Janus board is a LIFE SAVER and may >mean some super CW performance from the current SDR-1000 hw? >bk de ken or, just buy a second SDR as a receiver. Jim ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
At 03:22 PM 5/21/2006, Mike Naruta wrote: >And if you gotta have QSK, when the new software >comes out, just buy another SDR-1000 receiver >and you can run full duplex.:) That is a fairly straightforward approach to the "full duplex" need. And, it pushes the cost onto just those who want the capability (you could clearly use a 1Watt version for the "receiver" side, too). However, it should be pointed out that there is no inherent reason why the existing SDR1000 hardware and a PC cannot do microsecond scale QSK (depending on how fast the relays are, more than anything). It's mostly a matter of spending the (huge) amount of work involved in making a full duplex windows audio application that interacts with the hardware. Considering the amount of work involved in doing the latter, and the limited software development resources available, it's probably not a good investment of those resources. Personally, I'd rather see a push to a better separation between DSP and user interface in the Windows environment (as in running as separate tasks/processes), which would be of more general applicability than high performance QSK. For example, having a control and audio interface that was sufficiently decoupled from the PowerSDR UI would allow third party digital modes software to work without things like VAC, the use of dual sound cards, or serial port emulators. That was one of the high priority things discussed a year or so ago, but which has languished as other issues have been attacked. Jim ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
I seem to remember mention of a solution found right there at Dayton - some tweak to the soundcard config, perhaps, resulting in successful semi-breakin capability at speeds around 60wpm, but not full QSK. I guess we need Bob or Gerald to spell out the details. Pete > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Ken N9VV > Sent: Sunday, May 21, 2006 11:15 PM > To: Christopher T. Day > Cc: Ron Hinton; Flex > Subject: Re: [Flexradio] Cw Latency Problem Solved? > > I have listened to that part of the recording again today (now on > teamspeak) and he clearly said that "the current problem and > limitation is the SOUNDCARD and not the SDR-1000 hardware". > So I guess that means that the HPSDR Janus board is a LIFE > SAVER and may mean some super CW performance from the current > SDR-1000 hw? > bk de ken > > > Christopher T. Day wrote: > > Toby, > > > > I'm not certain, but I suspect this was a comment about the > SDR-X, not > > the SDR-1000. I doubt that there is a simple full-QSK solution with > > the latter given its half-duplex design. > > > > > > Chris - AE6VK > > > > > > -Original Message- > > From: Toby Pennington [mailto:[EMAIL PROTECTED] > > Sent: Sunday, May 21, 2006 12:02 PM > > To: Flex > > Cc: Ron Hinton > > Subject: [Flexradio] Cw Latency Problem Solved? > > > > I was just told by someone that Gerald made the comment on > Teamspeak > > last night that the cw latency problem had been solved. Someone is > > already able to send cw at 60 wpm QSK with no latency and > has found a > > way to do this. > > > > Does anyone else know about this and in particular how is this > > achieved. by a software change or hardware addition. Also does > > anyone know about the timeline for this improvement to the > SDR 1K. > > > > Toby W4CAK > > -- next part -- An HTML attachment was > > scrubbed... > > URL: > > > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachme > > nt > > s/20060521/d293d1ed/attachment.html > > ___ > > FlexRadio mailing list > > FlexRadio@flex-radio.biz > > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > > Archive Link: > > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > > FlexRadio Homepage: http://www.flex-radio.com > > > > > > ___ > > FlexRadio mailing list > > FlexRadio@flex-radio.biz > > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > > Archive Link: > > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > > FlexRadio Homepage: http://www.flex-radio.com > > > > ___ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
And if you gotta have QSK, when the new software comes out, just buy another SDR-1000 receiver and you can run full duplex.:) Mike - AA8K Ken N9VV wrote: > I have listened to that part of the recording again today (now on > teamspeak) and he clearly said that "the current problem and > limitation is the SOUNDCARD and not the SDR-1000 hardware". So I > guess that means that the HPSDR Janus board is a LIFE SAVER and may > mean some super CW performance from the current SDR-1000 hw? > bk de ken > > > Christopher T. Day wrote: >> Toby, >> >> I'm not certain, but I suspect this was a comment about the SDR-X, not >> the SDR-1000. I doubt that there is a simple full-QSK solution with the >> latter given its half-duplex design. >> >> >> Chris - AE6VK ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
Ok, I misremembered. I'll have to review the recording. Chris - AE6VK -Original Message- From: Ken N9VV [mailto:[EMAIL PROTECTED] Sent: Sunday, May 21, 2006 8:15 PM To: Christopher T. Day Cc: Toby Pennington; Flex; Ron Hinton Subject: Re: [Flexradio] Cw Latency Problem Solved? I have listened to that part of the recording again today (now on teamspeak) and he clearly said that "the current problem and limitation is the SOUNDCARD and not the SDR-1000 hardware". So I guess that means that the HPSDR Janus board is a LIFE SAVER and may mean some super CW performance from the current SDR-1000 hw? bk de ken Christopher T. Day wrote: > Toby, > > I'm not certain, but I suspect this was a comment about the SDR-X, not > the SDR-1000. I doubt that there is a simple full-QSK solution with the > latter given its half-duplex design. > > > Chris - AE6VK > > > -Original Message- > From: Toby Pennington [mailto:[EMAIL PROTECTED] > Sent: Sunday, May 21, 2006 12:02 PM > To: Flex > Cc: Ron Hinton > Subject: [Flexradio] Cw Latency Problem Solved? > > I was just told by someone that Gerald made the comment on Teamspeak > last night that the cw latency problem had been solved. Someone is > already able to send cw at 60 wpm QSK with no latency and has found a > way to do this. > > Does anyone else know about this and in particular how is this > achieved. by a software change or hardware addition. Also does > anyone know about the timeline for this improvement to the SDR 1K. > > Toby W4CAK > -- next part -- > An HTML attachment was scrubbed... > URL: > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachment > s/20060521/d293d1ed/attachment.html > ___ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > > > ___ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
I have listened to that part of the recording again today (now on teamspeak) and he clearly said that "the current problem and limitation is the SOUNDCARD and not the SDR-1000 hardware". So I guess that means that the HPSDR Janus board is a LIFE SAVER and may mean some super CW performance from the current SDR-1000 hw? bk de ken Christopher T. Day wrote: > Toby, > > I'm not certain, but I suspect this was a comment about the SDR-X, not > the SDR-1000. I doubt that there is a simple full-QSK solution with the > latter given its half-duplex design. > > > Chris - AE6VK > > > -Original Message- > From: Toby Pennington [mailto:[EMAIL PROTECTED] > Sent: Sunday, May 21, 2006 12:02 PM > To: Flex > Cc: Ron Hinton > Subject: [Flexradio] Cw Latency Problem Solved? > > I was just told by someone that Gerald made the comment on Teamspeak > last night that the cw latency problem had been solved. Someone is > already able to send cw at 60 wpm QSK with no latency and has found a > way to do this. > > Does anyone else know about this and in particular how is this > achieved. by a software change or hardware addition. Also does > anyone know about the timeline for this improvement to the SDR 1K. > > Toby W4CAK > -- next part -- > An HTML attachment was scrubbed... > URL: > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachment > s/20060521/d293d1ed/attachment.html > ___ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: > http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > > > ___ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ > FlexRadio Homepage: http://www.flex-radio.com > ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Cw Latency Problem Solved?
Toby, I'm not certain, but I suspect this was a comment about the SDR-X, not the SDR-1000. I doubt that there is a simple full-QSK solution with the latter given its half-duplex design. Chris - AE6VK -Original Message- From: Toby Pennington [mailto:[EMAIL PROTECTED] Sent: Sunday, May 21, 2006 12:02 PM To: Flex Cc: Ron Hinton Subject: [Flexradio] Cw Latency Problem Solved? I was just told by someone that Gerald made the comment on Teamspeak last night that the cw latency problem had been solved. Someone is already able to send cw at 60 wpm QSK with no latency and has found a way to do this. Does anyone else know about this and in particular how is this achieved. by a software change or hardware addition. Also does anyone know about the timeline for this improvement to the SDR 1K. Toby W4CAK -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachment s/20060521/d293d1ed/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] Cw Latency Problem Solved?
I was just told by someone that Gerald made the comment on Teamspeak last night that the cw latency problem had been solved. Someone is already able to send cw at 60 wpm QSK with no latency and has found a way to do this. Does anyone else know about this and in particular how is this achieved. by a software change or hardware addition. Also does anyone know about the timeline for this improvement to the SDR 1K. Toby W4CAK -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20060521/d293d1ed/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
