[NSRCA-discussion] curious - Transmitter Specs...

[Atwood, Mark]

All of this seems very reminiscent of CD's first coming to the market.

New technology invariably brings a shift in the metrics and specs that we use to evaluate it.  So yes, Latency is the new holy grail, but that's probably accurate.

Quick rewind.  Prior to CDs, shopping for stereo equipment was all about reading the specs, Total harmonic distortion, Signal to Noise ratios, blah blah.  Good specs (for the most part) meant good sound.  And as with all multi component systems, quality depended on the lowest quality component in the system.  A great amp was only as good as the speakers it was driving...and so forth.

Then came Compact Discs, and initially, people were still looking at Signal to Noise ratios on CD players.  It took a few years before it set in that the signal to noise ratio was SO high (unlike a phono or tape deck) that even the crappiest CD players had Signal to Noise ratios that were far superior to anything the human ear could hear and THD that was for all purposes, zero.   On the other hand, new specs DID add value.  Sampling rate, digital to analog conversion rates, etc, became the new measures by which to purchase.    As these have evolved, even those became meaningless to all but the extreme audiophile as again, even the cheapest players had specs that exceeded our ability to hear the difference.

We have the same phenomenon occurring in our hobby.    Latency is a new measure for all intents and purposes, since in there was little variability in the PPM and AM days.

I would argue to all that resolutions above 512, and certainly above 1024, are no longer the weakest component in the system.  Slop in our servo gears and  control linkages, even the best ball bearing ones, still exceed that of a single point of resolution at 1024.    That's good news.   Just like with CD's, it means even the less expensive radios now have resolution that exceeds our needs.

Latency has become a concern only because the early versions of 2.4 had some high latency.  I can NOT knock pioneers who pave the way for the rest to follow and improve on.   We only have faster systems because they brought the first "slow" ones to market and gave us a starting point.

But we're quickly approaching the point where IMHO, latency will be just as irrelevant as resolution in that all the systems will be faster than we're able to perceive and discern any difference.

Yeah, there will always be those that purchase on the technical superiority of a product, but practically speaking, they'll be equals.

Ok, that's my $0.02

I think I'll go play an album...

Mark Atwood
Paragon Consulting, Inc.  |  President
5885 Landerbrook Drive Suite 130, Cleveland Ohio, 44124
Phone: 440.684.3101 x102  |  Fax: 440.684.3102
mark.atwood at paragon-inc.com<mailto:mark.atwood at paragon-inc.com>  |  www.paragon-inc.com<http://www.paragon-inc.com/>

From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Bill's Email
Sent: Tuesday, March 23, 2010 12:45 PM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] curious

Andrew Jesky wrote:
I'm with you on this one Mark, I could notice the latency a little bit in some systems but the servo grouping is nothing that I can tell. I think the guys that really see this are the heli guys. I have talked to many of them and they do tend to tell me they can "feel" the difference. They are using much more servo throw all the time between positive and negative collective as well as cyclic.

Andrew



Andrew is right, this all got started with the heli guys who flew CCPM. On a big plane grouping is noce just to minimize servo stress and current draw, but it is not something you are going to feel while flying. And in a glider the only thing I ever work hard on matching is that the flap throw is matched through the entire range of movement.

Like I said, a couple of years ago nobody even heard of latency, now it is the Holy Grail.




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