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Old Feb 01, 2010, 07:10 PM
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Originally Posted by DougV View Post
You welcome Pete.

Kai_Shiden: Futaba FASST uses 36 channels from the band.

Doug.
Cool, thanks Doug, I like the sound of 36 channels. Especially since I'm doing demo flights at the NW Model Hobby Expo mid month. I figure my helis on Spektrum would have been a recipe for disaster in the show building (the indoor flying area and the vendors booths are all in the same building).

Unfortunatetly I wasn't a club member till this purchase (was long ago), but at least I still have enough stuff to buy that I'll make use of being a club member this year (still have quite a few more GY520's to buy , and RX's).

-Kai
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Old Feb 01, 2010, 07:15 PM
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Or you guys can pay 3 easy payment from tower, once u do the first payment they send you're radio.
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Old Feb 01, 2010, 07:21 PM
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The 8FG is a very nice radio, just this weekend we had 6 new 8FG's at the field.
I already transfered 8 different models from my 12FG to the 8FG, and I'm very happy with this radio.

Doug.
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Old Feb 01, 2010, 07:44 PM
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Originally Posted by Kai_Shiden View Post
Cool, thanks Doug, I like the sound of 36 channels. Especially since I'm doing demo flights at the NW Model Hobby Expo mid month. I figure my helis on Spektrum would have been a recipe for disaster in the show building (the indoor flying area and the vendors booths are all in the same building).

Unfortunatetly I wasn't a club member till this purchase (was long ago), but at least I still have enough stuff to buy that I'll make use of being a club member this year (still have quite a few more GY520's to buy , and RX's).

-Kai
__________________________________________________

You are dead wrong on the Spektrum performance but I hope you enjoy your 8FG.
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Old Feb 01, 2010, 07:55 PM
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Originally Posted by onewasp View Post
__________________________________________________

You are dead wrong on the Spektrum performance but I hope you enjoy your 8FG.
Backup your acusation then, tell me how I'm wrong.

I'm already getting lag and lockouts on spektrum (admittedly, on AR6100's, so it could be caused by RF frontend saturation) at my indoor club, which will have significantly active less radios than at the hobby show. It won't just be us flying, but also vendor booth demonstrations, wireless networks, battlebots, boats, cars, trucks, and god knows what else on 2.4ghz.

I see no reason to buy more RX's that I have zero faith in, my last purchase was an AR6110 that I put on a brand new heli, it failed intermittenly and kept cutting out, this was not a BEC issue (I run a YGE-18 with large switching BEC in it), I swapped to one of my older AR6100's and the cutout problem went away immediately (no other components swapped).

Straight up, DSM2 is more susceptible to interference than a frequency hopping protocol is, if you can argue that point go ahead and try.

-Kai
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Old Feb 01, 2010, 08:03 PM
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Originally Posted by Kai_Shiden View Post
Backup your acusation then, tell me how I'm wrong.

I'm already getting lag and lockouts on spektrum (admittedly, on AR6100's, so it could be caused by RF frontend saturation) at my indoor club, which will have significantly active less radios than at the hobby show. It won't just be us flying, but also vendor booth demonstrations, wireless networks, battlebots, boats, cars, trucks, and got knows what else on 2.4ghz.

I see no reason to buy more RX's that I have zero faith in, my last purchase was an AR6110 that I put on a brand new heli, it failed intermittenly and kept cutting out, this was not a BEC issue (I run a YGE-18 with large switching BEC in it), I swapped to one of my older AR6100's and the cutout problem went away immediately (no other components swapped).

Straight up, DSM2 is more susceptible to interference than a frequency hopping protocol is, if you can argue that point go ahead and try.

-Kai
Every body with spektrum at my club have issue and lock out, except not me and one of my flying body. Me and this guy never had issue with spektrum radios, but the rest of the club member with spektrum radio have issue. Spektrum have issues and they should recall them. Might be just the receivers, jr is dsm2 and i haven't heard any jr issue. I'm happy with my futaba 8fg.
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Old Feb 01, 2010, 08:44 PM
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Originally Posted by jcervantes11 View Post
Every body with spektrum at my club have issue and lock out, except not me and one of my flying body. Me and this guy never had issue with spektrum radios, but the rest of the club member with spektrum radio have issue. Spektrum have issues and they should recall them. Might be just the receivers, jr is dsm2 and i haven't heard any jr issue. I'm happy with my futaba 8fg.
The outdoor club I fly with is the same way I have far less issues than most of them do, the indoor club I'm the one of the few recognizing the issues so far (but I'm also one of the few that flys 3D helis down on the deck, most are plane guys).

At the both outdoor club I fly at it's in a valley with houses on the hills all around it, there are certain areas of the field that seem to be RF concentrations where all the lockout issues seem to happen. But they are on the far ends of the field, where I fly upclose most of the guys fly warbirds and use the entire field.

I'm quite religious about holding up my Spektrum TX's when I turn them on and try to fire up in a position where I can visibly see all the other Spektrum antennas, that way my radio sees them as well during it's scan. I also make sure to stand slightly turned to the side while flying so that there is a higher chance of those back behind the flightline turning on their TX's can "hear" mine during their scan. That works great outdoors, but indoors we're clustered much closer and there are more bodies that can absorb the signals.

What I've noticed is that the more variety of 2.4ghz TX's that we have at indoor (we're mostly Spektrum and a spattering of FASST and Assan), the slower the response gets on my DX7. There are varying levels of response I can deal with, I know that even frequency hopping will have a saturation limit that it's performance degrades past as well, I know there is no "magic bullet", I'm just of the opinion that decent frequency hopping will handle it better than being locked into just 2 frequencies.

The main time I have lockout issues is when I'm flying with the indoor car racing guys, which will have 20 TX's fired up at once (inside of a hangar with metal doors & roof and metal I-beam rafters, with all kinds of RF reflection, and most of those drivers standing shoulder to shoulder at the driving stand).

I'm also one of the more aggressive pilots, and will fly my helis with more aircraft in the air than the other helis guys (I'll also be the first to admit, that helis are much more susceptible to RF issues than planes, electronics are clustered tight and vibration is a fact of life ). Most of the other heli flyers wait until nearly the entire hangar is clear, where my first experiences with flying with others in a parking lot where I just learned to dodge planes from every direction or I wouldn't get any flying time .

-Kai

P.S. All of my aircraft also pass range tests with the motors running, from all the way across the hangar while piroetting on the ground with the range test button held (I know even going that far is still not perfect with multipath blocking issues, but that's the best I can do )
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Old Feb 01, 2010, 08:57 PM
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I have been doing a little research before purchasing a 2.4 system. It seems to me that FASST is superior since both FASST and DSM2 use DSSS modulation but DSM2 locks on to 2 channels but FASST shifts between 36 channels. I am not an expert by any means but in my simple little head FASST just seems more solid.

Tony
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Old Feb 01, 2010, 09:02 PM
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Originally Posted by HogCrewChief View Post
I have been doing a little research before purchasing a 2.4 system. It seems to me that FASST is superior since both FASST and DSM2 use DSSS modulation but DSM2 locks on to 2 channels but FASST shifts between 36 channels. I am not an expert by any means but in my simple little head FASST just seems more solid.

Tony
Get you're self a 7c or 8fg, you'll be happy with it.
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Old Feb 01, 2010, 09:04 PM
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Originally Posted by Kai_Shiden View Post
The outdoor club I fly with is the same way I have far less issues than most of them do, the indoor club I'm the one of the few recognizing the issues so far (but I'm also one of the few that flys 3D helis down on the deck, most are plane guys).

At the both outdoor club I fly at it's in a valley with houses on the hills all around it, there are certain areas of the field that seem to be RF concentrations where all the lockout issues seem to happen. But they are on the far ends of the field, where I fly upclose most of the guys fly warbirds and use the entire field.

I'm quite religious about holding up my Spektrum TX's when I turn them on and try to fire up in a position where I can visibly see all the other Spektrum antennas, that way my radio sees them as well during it's scan. I also make sure to stand slightly turned to the side while flying so that there is a higher chance of those back behind the flightline turning on their TX's can "hear" mine during their scan. That works great outdoors, but indoors we're clustered much closer and there are more bodies that can absorb the signals.

What I've noticed is that the more variety of 2.4ghz TX's that we have at indoor (we're mostly Spektrum and a spattering of FASST and Assan), the slower the response gets on my DX7. There are varying levels of response I can deal with, I know that even frequency hopping will have a saturation limit that it's performance degrades past as well, I know there is no "magic bullet", I'm just of the opinion that decent frequency hopping will handle it better than being locked into just 2 frequencies.

The main time I have lockout issues is when I'm flying with the indoor car racing guys, which will have 20 TX's fired up at once (inside of a hangar with metal doors & roof and metal I-beam rafters, with all kinds of RF reflection, and most of those drivers standing shoulder to shoulder at the driving stand).

I'm also one of the more aggressive pilots, and will fly my helis with more aircraft in the air than the other helis guys (I'll also be the first to admit, that helis are much more susceptible to RF issues than planes, electronics are clustered tight and vibration is a fact of life ). Most of the other heli flyers wait until nearly the entire hangar is clear, where my first experiences with flying with others in a parking lot where I just learned to dodge planes from every direction or I wouldn't get any flying time .

-Kai

P.S. All of my aircraft also pass range tests with the motors running, from all the way across the hangar while piroetting on the ground with the range test button held (I know even going that far is still not perfect with multipath blocking issues, but that's the best I can do )
Weired thing is that our club is in a active airport, we're on the far out run way which is for crop duster, the other runway is for people with private planes and such. Fm is being bang for sure and 2.4 theres not to much people with'em but yet those that do usually own spektrum and they have issue except one guy and me. I do would love a jr radio but i have this futaba 8fg and i really like it.
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Old Feb 01, 2010, 09:09 PM
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To be fair to Spektrum, they do have model match and servo sync exclusively due to their patents on those features. I know quite a few people that model match saved their butts (trying to take off with the wrong model loaded).

While model match is quite valuable to many, I question how much servo sync really helps. My concern with servo sync, is that sending signals to multiple servos at once in mixing modes, creates higher peak servo draw on BEC's (while the average stays the same, higher peaks can cause more heat buildup).

I came from 72mhz though without model match, so I'm quite diligent about loading the right model anyways (even though I have model match ).

And for those into flybarless helis, Spektrum remote RX's work directly with the Mikado Mini-Vbar, without a Spektrum RX (saves quite a bit of cableing mess).

-Kai
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Old Feb 01, 2010, 09:12 PM
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[QUOTE=Kai_Shiden;14

Straight up, DSM2 is more susceptible to interference than a frequency hopping protocol is, if you can argue that point go ahead and try.

-Kai[/QUOTE]

Only and I MEAN only on paper using a very simplistic approach..
I've talked with a number of RF engineers here and elsewhere and each of them has said that to produce any paper logically and factually supporting the superiority of one vs the other is sheer folly. I.E. DSM2 vs. FASST, FHSS, DSSS or any combination thereof.

I am NOT an RF engineer, simply a Gen Class HAM of 30 odd years who has been flying 2.4GHz SS since it first hit the market . I have flown RC Precision for 50+ so I am not a new kid on the block.
With all the diversities in play, sequence. temporal, antenna etc. etc. you are in a numbers game which cannot be won.
Witness at the Joe Nall this year and later at the IRCHA that 500+ in one and 700+ in the other were operating roughly simultaneousl, including the pits.

Example: you can operate two DSM2 sets (actually many more than simply two) simultaneously, on the self same frequencies. without a moments interference! One diversity example, temporal ,will accomplish this and you've many other combos to go.
The number of DSM2 sets which can be operated simultaneously is quite frankly an unknown number. Probably always will be.

Throw in FASST sets in the same environment and they too will work. They too are operative in startling numbers.

You seem to be viewing SS as if it were 27, 35, 40, 50, 53, 72, 75 MHz. which can be viewed as a flat plane. SS is anything but a flat plane.
SS is not limited in that manner.
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Old Feb 01, 2010, 09:28 PM
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Originally Posted by onewasp View Post
Only and I MEAN only on paper.
I can respect that, however I'm talking from my own firsthand experience with actual issues. When you can show me documented proof that so many radios were functioning at the same time I'll be glad to read it. That's like saying that you've heard of thousands of DSM2 radios being on around the world at once.

Spektrum has documented that the way it scans channels, if it see 39 radios in use, the 40th radio will not transmit until it sees 2 open channels free up (this is to limit overlap). So in your (flawed) examples of Joe Nall and IRCHA are rediculous (although it would be quite impressive looking if there really were 500 aircraft, or 700 helis in the air at once).

In the case of Spektrum (which is all I was referencing), yes it does happen to utilize 2.4ghz in the same way as our older TX's do, since it doesn't hop, it divides up the band into 80 "channels", and yes, 2 or more radios can overlap and still be fine (due to multipath). FASST using 36 frequency slots and hopping every 2ms acts more like a typical wireless 802.11* network does and has packet collision detection.

The above information is right on Spektrum's faq page: http://www.spektrumrc.com/DSM/FAQ.aspx

Those RF engineers you talked to were working from incomplete information (that you probably gave them, unless you gave them the patent or FCC information on how Spektrum DSM2 works AND gave them time to think it through), therefore their answers are not incorrect to the scope of the information they were given by you. Your questions were probably incorrectly formulated.

Your credentials mean nothing to me, I already read them in another thread you posted in. I'm talking indisputable facts, what your experience is has no bearing on the conversation until you post links to references.

-Kai
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Old Feb 01, 2010, 09:33 PM
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Great article.

http://www.rcmodelreviews.com/spreadspectrum01.shtml
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Old Feb 01, 2010, 09:38 PM
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Originally Posted by Kai_Shiden View Post
I can respect that, however I'm talking from my own firsthand experience with actual issues. When you can show me documented proof that so many radios were functioning at the same time I'll be glad to read it. That's like saying that you've heard of thousands of DSM2 radios being on around the world at once.

Spektrum has documented that the way it scans channels, if it see 39 radios in use, the 40th radio will not transmit until it sees 2 open channels free up (this is to limit overlap). So in your (flawed) examples of Joe Nall and IRCHA are rediculous (although it would be quite impressive looking if there really were 500 aircraft, or 700 helis in the air at once).

In the case of Spektrum (which is all I was referencing), yes it does happen to utilize 2.4ghz in the same way as our older TX's do, since it doesn't hop, it divides up the band into 80 "channels", and yes, 2 or more radios can overlap and still be fine (due to multipath). FASST using 36 frequency slots and hopping every 2ms acts more like a typical wireless 802.11* network does and has packet collision detection.

The above information is right on Spektrum's faq page: http://www.spektrumrc.com/DSM/FAQ.aspx

Those RF engineers you talked to were working from incomplete information (that you probably gave them, unless you gave them the patent or FCC information on how Spektrum DSM2 works AND gave them time to think it through), therefore their answers are not incorrect to the scope of the information they were given by you. Your questions were probably incorrectly formulated.

Your credentials mean nothing to me, I already read them in another thread you posted in. I'm talking indisputable facts, what your experience is has no bearing on the conversation until you post links to references.

-Kai
Well, spektrum failed in my field so spektrum is not in my interest anymore, i haven't seen any futaba fail. thumbs up to futaba and thumbs down for spektrum. I reconmend everyone the futaba 8fg. Oh one thing, has anybody went through looking up the wfly 2.4 radio? http://www.wflysz.com/en/ProductView...200&SortID=137
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