73, Barry N1EU
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Posted 3 years ago
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however such mesurements are verys depends on the filters shape factor you know what was discussed ex. here: https://community.flexradio.com/flexradio/topics/cw_filter_shape_factors?topic-reply-list%5Bsettings%5D%5Bfilter_by%5D=all
i am not againts with you notes but necessary to have apple-to-apple compare
or we need to talk concerning introduction of the Shape Factor "tuning knob" into the F6000
P.S. personally i have no issue with Latency, usually my setup is CW 400Hz and 32WPM and higher
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SDR's have to take analog signals and digitize them to send them over a network or to process them. On the other end of the pipe, the computer or terminal (Maestro, etc.) has to convert the digital stream back to analog for our ears.
The TV in our living room was purchased in 1974, and has a "converter box" to receive OTA HDTV and present it on that old set. We also have a modern HDTV in another room. The latency between the two when you're standing halfway between them is on the order of FIVE SECONDS.
Yup! Latency is with us.
I've gone back to analog wires connecting my stuff together, and put away all the fibre gear.
Jim
K0UNX
Littleton, Colorado
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Andy K3UK
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This is nothing new. If you were to take a Flex User poll and ask them to pick between lower latency versus unlimited filter width, the unlimited filter width would win out. I myself have a K3 and also a Kenwood TS-990S.
The K3 has hardware filters and so does the Kenwood. And of course you can adjust the width of the filter with the limits of the firmware that is installed. Do you use your Flex for contesting?
The contest radio club I belong to was to have N4HY, who was one of the architects of Flex Radio at our club meeting tonight. But due to illness he is not able to make it. I was going to ask him some questions related to the Flex after the meeting. But that will have to wait for another time as they say.
I was going to purchase a Flex. I was very impressed with the hardware performance. But with all the issues that are software related, I purchased the 990S. I just see too many issues when it comes to software. That is why I was very apprehensive. Mark Griffin, KB3Z
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I'm under the impression that Flex is seriously going after the contester market, so I think this IS an issue.
Maybe the filter slopes need to be slightly shallower but that's not currently a configurable parameter.
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Lew
N4CO
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W7NGA dan
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Lew
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So, the issue would be when the transmitting station finishes calling CQ, you will not be able to know this until ~165ms after the fact (should we include transit times?). You hear him stop, your brain processes this fact and introduces its own latency, and your arm eventually presses the CW key to transmit his call.
Instead of buying a new radio, wouldn't one be almost better off to simply hone their reflexes? Reflex exercises. See the light, press the buzzer. Or maybe just move closer to the DX station(s) and buy yourself a millisecond? Hehehehe ....
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I was going to do a SO2R situation when I considered adding the flexradio. I had a Top Ten DX Doubler all ready to go. But after getting my 990S I have a main receiver as well as a sub receiver.
That is one option I did not have with my K3. So when I use my 990S with N1MM Plus for contesting I have the software set for S02R and I can see a bandmap not only for spots on the main receiver but also the Sub Receiver.
Currently my K3 is sitting on a couch. I have it as a backup rig just in case the 990S falls to pieces. And I hope that doesn't happen! I just used my 990S for the CQWW SSB and CW contests, and I prefer it over my K3.
Just personal preference I guess.
Hopefully this gives you some insight on how I operate when it comes to contests.
With day to day operating I will probably be on 40 meter CW which is what I have the main receiver on. The sub receiver I usually have on 40 meter SSB. I have 2 speakers so I can listen to both.
Mark Griffin, KB3Z
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You make an excellent point that neither Flex or Elecraft were at HRO. Elecraft is basically either a kit or assembled. And you pick the options that you want. Flexradio is pretty basic except for adding a GPS or Antenna Tuner on the 6300. Both Elecraft and Flexradio seem to be quite successful with their marketing strategy.
My first major radio was a TS-940 and I was going to reactivate that one. But decided to get the 990S instead. Plus the deal that HRO had where it was about 1500 dollars less was a major reason why I purchased it. It is a large, heavy rig, but with all the features I really like it. There is a learning curve, but that will happen with any piece of equipment you buy today.
Mark Griffin, KB3Z
Andreas Junge, Elmer
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are you measuring the delay at the speaker output in the back of the radio or are you using the "Remote" audio? I am sure the latency table from the manual is based on output at the speaker port of the radio.
Routing the audio through the "Remote" seems to add a considerable amount of latency.
73, Andreas, N6NU
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I suspect that the current 6K steep filter slopes is a double negative for cw contesting - it results in greater latency and it stops you from hearing off-frequency callers when you're running. Not-too-shallow, not-too-steep is what's needed - like the PowerSDR "1024 buffers" slope that matches the Orion slope:

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My opinion is that this latency is real but not having any effect on the ability to DX or Contest. I have been grinding away using SO2R and have not seen any negative effect in SSCW or ARRL 160. I can listen to my second harmonic and get a feel for the latency. I don't change my operating at all.
Being on the DXpedition side of things...some delay before calling is a GOOD thing. Almost everyone calls at the same time. The DX station is usually tuning away from the last station worked in a split and it takes a half second before he can hear the next call. Notice how many times in a phone pileup that the DX station will ask for the Echo Uniform or cw pileup EU? That is because you were the last station he heard.
If you are running on cw, two or three stations on the same freq is uncopyable but you will notice the last couple of letters and work that guy.
So far, other than knowing there is some latency, it has not had any impact on my operating. Should it be improved as much as possible? Yes, I would agree.
I was more concerned about turnaround time. The time it takes to go from TX to RX. In SO2R, I am very impressed how quickly the 6700 switches. The second I CQ on one slice, I am listening to the second slice. Once done CQing, I am now instantly listening to the first slice. Is there a real delay? Yes, but not perceptible or meaningful in real time operating.
You can actually listen full duplex in SO2R, so no actual noticed delay unless you are near your harmonic.
73, Craig K9CT
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I just ran some more experiments. Latency drops from 165msec to about 100msec when I increase to 422Hz bandwidth. I then ran some passband plots to look at the slopes and compared them with my Orion II (roofing filter plus dsp at their steepest setting of "199 taps"). Yes, the Flex filter slope is slightly shallower at 422Hz than 400Hz, accounting for the lower latency. BUT the Orion filter slope is MUCH shallower still than even the 422Hz filter slope. I would post some plots but the only software I have available produces logarithmic traces and they look a little strange.
This data seems to indicate that Flex has really skewed the filtering to extremely steep filter slopes without offering the option (yet?) of shallower slopes. Steep filter slopes are great when I'm tuning a crowded band or I have major QRM on the side when running. But otherwise, shallower filter slopes comparable to what's being provided in rigs like the Orion II and K3 will result in MUCH lower latency and would also allow me to hear off-frequency callers, which I generally want. On another note, when I'm just cw ragchewing, I really prefer the tone of a shallower sloped filter.
73, Barry N1EU
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Please do not take this the wrong way and I hope you do the same so you will agree. While working a contest pileup I go from loudest to weakest. I think it is just human nature to be lazy and work the easiest stations first.. Even if I get a quick prefix that is subsequently covered by a loud full call , I will default to the loud full call unless the prefix copied was a multiplier. I am not saying that your calls are not loud, at the worst I am just saying there may be louder stations calling at the same time and the station being called also goes from loudest to weakest as well.
At the same time, I think a leading edge technology machine like the flex SS rigs should be the envy of other manufacturers when it comes to measurements like this and am disappointed that they currently are not in this particular measurement. : (
Andreas Junge, Elmer
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thanks for measuring this! BTW, would it be possible to get the numbers for the "Remote" setting? To me it feels like it adds another 150 to 200ms.
73, Andreas, N6NU
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Look through my videos on Youtube. You'll see I get through pile ups usually in the first couple of calls. You'll also notice I repeat my callsign twice to ensure I'm tail end charlie. One of them, the one with the President Lincoln where I get through a pileup to AU3NIAR I'm only running 21W into a Hexbeam and manage to get through second call.
At the end of the day though the biggest delay is actually in the operator.
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The delay is irrelevant
It's irrelevant to YOU. Several cw contesters have contacted me off-line and told me it's not irrelevant to them.
73, Barry N1EU
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Here's how asinine the argument is and the that of claims your friends are making. At 20WPM a dit is 50ms. Being generous and assuming a 50WPM send rate then at most they're a dash behind the fastest person who gets their transmission out first. And that's at 50WPM. That is nowhere near a good enough difference to be the make or break between making a contact or not.
And if its so critical I assume you're all using CW keyers that are analysing the RX audio for the millisencond the last dit is sent so you're not wasting time with the 0.7 seconds of human reaction time so there isn't a single millisecond wasted more than is needed or are you wasting time reaching for the function key on the keyboard or the paddle/key?
Yours sincerely, someone who holds a first in world in class certificate for a CQ-WPX-RTTY contest and a bunch of first in class in England for contests including CQ-WW, CQWPX, IARU HF World Championship and ARRL International DX and who ranks consistently in the top 20% of all entries despite only running 100W, an inverted L and a Hexbeam at 36ft.
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The cw filter slopes can be softened a bit by going to slightly over 400hz BW and turning on APF10. But I suspect the APF might add even more latency.
Anyway, how did they get the latency down to 70msec on ANAN when they're even dealing with an ethernet roundtrip transport of the data since dsp is in the pc and not rig's FPGA? Sure seems like Flex should be beating ANAN.
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I am gonna have to side with M0GVZ on this. While I would definitely like to see Flex SS rigs have industry leading numbers wrt this issue, in the big scheme of things how big of a detriment are the current numbers wrt real world operating ? The only direct experience I have with this and I think it is noteworthy is operating the weekly NCCC cw sprint events. I think the bigger detriment for me is my ocf dipole at 35 feet, but that works out even better for this discussion. I mention the cw sprint events specifically because of their unique rules. A station can not sit on a freq and run stations. Once a qso is made they must qsy so if you do not get that station before another station does you are SOOL and must find someone else to work.
Ignorance can be bliss and I had no idea our rigs were so slow but not knowing this I operated them with the understanding that they were just as quick as the next rig. While my qso totals are about one half of the top scores in these events, I think this is more of a reflection of my antenna's performance and lack of experience in these events compared to the top scorers. In other words, I am not getting beat out consistently while answering a cq because my Flex SS is so slow. I am able to win my fair share of qsos by beating the other guy to this critical punch. Now if this is indeed an issue, I need to start playing my rig's handicap and should start transmitting as soon as I start to hear the last dah or 3 dits being sent by the station calling cq.
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Andreas Junge, Elmer
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I am also comparing a remote K3 with RemoteRig to the "Remote" audio setup of a Flex 6700 and the delay on the Flex is WAY higher than the RemoteRig. It feels like there is a 150 to 200 ms added on top of the necessary delay dictated by the filtering. I think there is room for improvement. RemoteRig can do it well....
73, Andreas, N6NU
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As I've said earlier the additional delay is a dash at 50WPM. Hardly world ending or contest losing and if you're blaming that for not making contacts in a contest then you're just another bad workman blaming their tools instead of their lack of ability.
Andreas Junge, Elmer
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Why does it matter? While you may not be able to tell a difference, at lot of us can and do. You should be happy with the performance you got. Let the rest of us help this fine company to make the Flex 6K line of radios the best in the market.
Why leave performance on the table if it can be improved? The hardware can do a lot, so I don't accept mediocre performance. They can and will do better than that. Not in this version, but maybe next. The Elecraft K3 would not be where it is today if it wasn't for all the user input and Elecraft's willingness to listen to them.
And yes, I do contest from a hill at 2000' with limited road access at times, so remote latency matters.
So please let's make this less personal and more about the data.
73, Andreas, N6NU
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Lew
N4CO
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https://community.flexradio.com/flexradio/topics/latency-1-4-improvement
73, Jay - NO5J
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But then given as CW ops seem to be the most vehement complainers (complain about people not sending uniform morse but then complain about perfectly spaced computer generated CW for example) it'll then be decided that this isn't good enough and you should have the same latency with the steep filters.
Actually thinking about it if you implement soft filters instead of a "anything outside of 14.030.00 to 14.030.400 will be completely ignored", that involves more maths and data processing than vertical skirts because you're then having to calculate different steps of attenuation at both decreasing and increasing increments.
In the linked thread K5UA makes a very important point and that is that having steep skirts is far more important in a contest than the extra delay. The only reason I bought a Flex for contesting is because the filtering of mechanical filters and DSP filtering implementation in conventional receivers is quite simply not good enough. The turnaround time is of no consequence to me until it starts to be measured in seconds. Far more time is wasted having to repeat information either way because a nearby station is overwhelming the station I'm in a QSO with than a 150ms latency will ever cause.
Would it be nice to have a lower latency? Probably if that is a thing that floats your boat. Are the vast majority of users likely to notice any difference? No. Only those more interested in numbers on a bit of paper rather than real world effect are going to be concerned.
I'll leave with this final point. It is interesting to note how many people were completely unaware of any issue until the QST review mentioned it, such is how little impact it has.
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One thing I would caution folks about. If someone says or implies their sense is that <such and such>, they are not wrong, it is a general feeling of how well something is to them. Sure, there may be things that aggravate or mitigate the effect as M0GVZ and Steve point out, but the 'take away' for an individual is not wrong, as that's how they feel about the subject. Devolving a thread into personalities and blame serve no useful purpose.
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A guide about better search terms would be nice.
73, Jay - NO5J
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TOR capable rigs are truly a delight to operate on CW using the examples for working DX that Barry presented earlier. Please do not throw away the "TOR" test/criteria just because *NONE* of the current rigs have that capability.
Latency is relevant to modern operation by operators who experienced the joy of true silky QSK in the past. When one is faced with spending $4K - $8K for a new rig, the Latency issue creates a truly major decision point. QSK is more of a necessity than just a preference for this operator.
thanks,
HNY de Ken N9VV
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Chris Tate - N6WM, Elmer
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I've been playing around with Faros from VE3NEA which monitors NCDXF beacons on 20 though 10 meters. I was hearing the signals but they weren't being recorded. After an email to VE3NEA I was told to adjust the delay correction so that recorded points cluster around the short path.
I did that with the filters set at their lowest latency and got a few points for each station. Then I move the filters to their sharpest setting and, roughly averaged, I was seeing about 156 ms of delay. The effect makes everything look like it is coming in on the long path.
Obscure. I know.
But here's my takeaway from this little experiment. It seems that, within reason of course, predictable latency through the filters (through the whole rig for that matter) is more important than low latency when it comes to measuring paths.
I'm not good enough to even consider 156 ms as impacting my ability to make a contact. More often it is fumbling with the key or living with a less-than-ideal antenna that keeps me at the back of the pack. But it is nice to finally figure out how latency can be important. Today I feel smart. Tomorrow it's back to being a pain in the neck.
73,
Kev K4VD
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settings just for knowing how they work and found that I can now use the slider for equal latency in all choosen bandwidth and modes. The numbers are +- 5mS.
The numbers: left is 0 - 1 - 2 - 3 and auto
In 0 : all modes and bandwidth 55 mS
In 1 : all modes and bandwidth 75 mS
In 2 : all modes and bandwidth 105 mS
in 3 : all modes and bandwidth 165 mS
In the -auto- position of the sliders there are different latencies for the bandwidth in CW and DIGI
from 55mS on 3-5KHz, 75mS on 1KHz, 105mS on 800Hz, and <400Hz 165mS. On SSB in auto there is always 165mS latency but you can choose from sliderposition 0 to 3 to change.
note: it is the receive latency when your partner sends a -did- and you can hear it on the 6500 after the delay in mS
best 73
Lee, Elmer
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73 W9OY
Ria - N2RJ, Elmer
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