- 568 Posts
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Posted 5 years ago
George Molnar, KF2T, Elmer
- 1681 Posts
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There are several contest ops here, and I believe the consensus is that the abilities the rig provides more than outweigh an imaginary fault.
.
- 452 Posts
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simply listen to your signal on an external receiver ... you might be surprised.
73's
dan W7NGA
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- 568 Posts
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I thought maybe that maybe with ver 1.4, moving some of the cpu work to the 6000 might change the turn time?
- 320 Posts
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The last thing we need is another contester than can hear stations that the Flex users can hear. :)
- 452 Posts
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latency - it's enough that you cannot realistically monitor and assess your signal real-time on an external receiver, and I suspect it could be an issue for the consummate contester.
dan W7NGA
- 4239 Posts
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One can press the PTT a split second before the other station finishes his "QRZ" and be right there on top of everyone else. In fact, I often see stations begin transmitting several seconds before the DX ends his transmission, presumably on order to get the drop on the competition. (I often wonder if they know that the other station cannot hear them until the DX station stops transmitting....)
Yes, timing is often more important than raw power, and articulation is often better than compression, but much of that timing is in the footswitch or VOX, or even more..in the operator's mind.
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- 568 Posts
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- 568 Posts
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The Flex-6700 turnaround time = 140ms
Per QST reviews
We went from one of the fastest to by far the slowest.
- 281 Posts
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So far down the list that it never crossed my kind and now that I know I hope it never crosses my mind again. The ability to hear thing and weed them out is far more important then 1/10th of a second
Mike
N9DFD
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Steve - N5AC, VP Engineering / CTO
- 1057 Posts
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Our read when we designed the signal chain for sideband was that a little latency was less important than good filtering. So we "maxed out" the filtering capabilities for sideband. The filter dynamically changes width in DIGx modes and in CW. If you would like to try out a shorter latency with reduced filtering capabilities, try running in DIGU instead of USB and set your filter width to greater than 2kHz. The latency will go down to what we consider to be a very minimal level.
The ARRL and others are not used to measuring radios that have complete flexibility in how things like this are controlled and so they put the radio in a given position and took a measurement. The measurement is accurate for that one setting, but is not a complete picture of what the radio can do (and in this case doesn't explain the tradeoff that we made). I'm sure I would have done just what they did. As you guys probably know by now, if you provide a compelling case for making a change in the radio there are very few things we cannot change. You can try using DIGU and let us know if you prefer it like this. There is actually a table in the owners manual with this information along with a description of how it works (see 29.6.4 on page 140).
George Molnar, KF2T, Elmer
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KY6LA - Howard, Elmer
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- 568 Posts
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Thanks for the informative reply and I now understand. So to answer our contesting friends concerns we need to explain to them that excellent filtering is more important than longer delay.
I guess a "contest mode" would be a nice marketing tool. :*)
72
K6OZY, Elmer
- 542 Posts
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Steve - N5AC, VP Engineering / CTO
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Tim - W4TME, Customer Experience Manager
- 9199 Posts
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Yes, but sharper filters result in greater signal propagation delays.
Chris Tate - N6WM, Elmer
- 976 Posts
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KY6LA - Howard, Elmer
- 3794 Posts
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All you need to do is to route your TX and RX audio via a DAX Channel.. and then have your device (speaker and mike) listen to those channels..
I could provide your friend with screen shots as to how to do it as that is how I do it with iPad Remoting via DAX..before Remote was available in 1.4
BTW,,, at times I get hit with the contesting bug and I can be a serious contestor... I have won my ARRL section using SDR's and have placed 2nd in World and #1 NA in a JIDX SSB Contest... so I can speak with some authority about contesting.....
It always helps to have a contesting station.. I have a 6700. SPE 2K-FA and a SteppIR MonstIR @85' located 600'ASL 1KM from the Pacific Ocean.. so by definition I will always do well in an Asia Pacific Contest without trying too hard.
So what is the difference between #2 in the world and #10 in the world when I was not trying too hard......
Basically its the operator's skill...
that 100ms latency is a mental factor.. if no one had pointed it out there is absolutely not doubt that it would not be an issue..as a great operator can win with even a lowly ICOM IC-756 Pro3...
- 64 Posts
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Could you give us some data that compares latency to filter skirts? While I'm not the contester that I used to be in my younger days, with the call WB4PDQ, I think this is worth further discussion. On CW a difference of 100 ms is very noticeable at 40 wpm contest speed.
- 824 Posts
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I have done hundreds of SSB contests both with and without the Flex and there is no difference that would ever make a difference in my score. If he really knew contesting and it was a pile up, it isn't about being first in, but being heard when there are less people calling.
I also contest with a remote base with about 100ms latency (and I have been for almost 10 years) and I have never noticed a difference where it would make an impact on my score.
It is 100% operator skill and nothing to do with the change over time. va3mw
- 495 Posts
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Barry N1EU
Steve - N5AC, VP Engineering / CTO
- 1057 Posts
- 1099 Reply Likes
https://community.flexradio.com/flexradio/topics/cw_filter_shape_factors?topic-reply-list%5Bsettings...
The same filters used in CW are also used in sideband so the same numbers apply.
- 64 Posts
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Excellent read, thanks. I didn't see any numbers for the associated latency of each bandwidth, however. Based on what Howard says below, I agree that latency will only matter to the average contester who does a lot of S&P. Hmmm...I think this means it is a spec that could be significant to a number of us average Joe's. I would propose, as someone else suggested, either having a contest latency switch, or make it prominently visible in the documentation how to choose low latency.
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Latency is a trade-off with filter slope steepness. To throw out a number, perhaps a 2:1 minimum filter slope is needed for serious ssb contesting when the least amount of latency is desired (i.e., sacrificing filter slope steepness for less latency).
Barry N1EU
- 625 Posts
- 283 Reply Likes
This reminds me of the guys who speed the "5nn" up to 65 WPM in a CW response - how much time did they really save and did it make a difference?
Whatever latency may be characteristic of the Flex is much outweighed by the various advantages that a Flex offers to contesters. I wouldn't be surprised if they didn't come out with a SDR-assisted category to level the playing field.
KY6LA - Howard, Elmer
- 3794 Posts
- 1640 Reply Likes
I can see where 100 ms might slow u down in S&P But As I said you are not running high rates in S&P. Even then a BIg Station will easily dominate most everyone else who beat you to the 100MS punch.
So I can only surmise that the Latency issue is. Not an issue for Big contest winning stations but might be an issue for someone in the middle of the oack.
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KY6LA - Howard, Elmer
- 3794 Posts
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Americans speak at 5-7 syllables per second - so 100ms is perhaps 1/2 a Syllable lost...So if they are saying Kilo Yankee Six Lima Alpha.. the lost sound would be half of Ki syllable.. something one easily correctly integrates back in your head..
Non Native English speakers talk at much slower rates so you likely would not even miss that first 1/2 syllable.
- 4239 Posts
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BTW... There are many other factors to reduced rate. For example, running to FAST on CW requires more repeats because you are sending over the heads of the majority of contesters. I have seen many articles that recommend speeds between 28-32 WPM, and no more than 35 WPM in a contest, especially if your call or report has lots of "dits" in it, (because they are the ones most prone to copying errors). I cannot fathom why some people see the need to send at 40, 45 or 50 WPM in a contest. They have gone well past the point of diminishing returns in the CW exchange game.
When rag chewing with friends or handling traffic with experienced operators, I can understand the advantage of very high speeds. But in contest style exchanges with operators of various skill levels, I think excessive speed is counter-productive. If nothing else, it wastes other people's time as they try to copy your call and decide if you are fair-game or a dupe. Frankly, I think that is kind of rude.
Ken - NM9P
- 64 Posts
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- 4239 Posts
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I run S&P all the time because I don't have enough antenna or power to RUN a frequency.
If that is the case, my best chance is often not to be the first syllable anyway, because I will likely get stomped by the stronger stations. Sometimes my best chance is to be the first of the second wave calls. "Timing" doesn't always mean being first, but often it means being the "smartest."
- 64 Posts
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FWIW, you are absolutely 100% spot on when working a DX pileup while not in a contest.
BTW, I am a CW contester. ;-)
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Tim - W4TME, Customer Experience Manager
- 9199 Posts
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- 79 Posts
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This means on average, the latency might result the other party getting a 1/2 syllable head start, given equal human response times.
It would be interesting to set up a double-blind test with variable Rx latency (radios not required) and see if unprepared subjects can even detect 100 mS, or if others can truly leverage that to their advantage. Until that is investigated I don't see pulling limited resources off higher priority tasks to implement something with unproven benefit, based on an allegation with multiple possible causes besides latency.
- 495 Posts
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Barry N1EU
- 79 Posts
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This is especially so since changing to lower latency would involve losing other filtering advantages. Any hypothetical advantage from reducing the 100 mS latency might be offset by worse filter performance. If poorer filtering caused just 1 in 20 QSOs to require a single 3 sec retransmit due to unintelligibility, overall contest performance would ironically be worse by using faster latency.
- 21 Posts
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