TimBle

amen

xlr82v2

My Feedback: (1)

Multipath issues. Antenna Shadowing. Brown-outs. Lost bind. Slow reconnect times. Who-knows-what other problems remain to be uncovered (or should I say "identified"...). All these are virtually non-existant issues with 72Mhz, and you guys still tout 2.4GHz as "Superior"?

I'll let you guys revel in not having to use the frequency board... I'll go grab my frequency pin and go fly.

DougV

I have none of those issues with the 2.4 system I use (More than 4 years now).

I lost two airframes on 72Mhz because of people turning the radios on without checking the frequency board first. I'll never go back to 72Mhz.

JMO,
Doug.

TimBle

these problems you refer to exist in only brand

dirtybird

My Feedback: (5)

In 72MHZ we have long ago identified the problems so there are no surprises.
Since 2.4GHZ systems are now nearly 5 years old I don't think we will find any new problems. They are more sensitive to the power supply due to the receivers using a microprocessor. BTW did you know digital servos use a microprocessor too?
They are also more sensitive to multipath due to the shorter wavelength.
But on the other hand:
1. They require smaller antennas. No wire hanging out the tail of your AC and no fishing pole on your TX.
2. The receivers are more bulletproof. There are no IF cans and only one small rugged crystal.
3. The receivers can be made smaller and cheaper. See item 2.
4. They are immune to interference from other systems at the field. No frequency control is required.
5. They have much greater resistance to any kind of interference. This includes that generated within the aircraft.
6. Th RF portion in the transmitter uses quite a bit less power than the 72RF system.

Overall 2.4GHZ systems are a great improvement over 72MHZ systems.

aussiesteve

Didn't Multiplex have a "72 mhz" style of system that had pretty much all of the features that are now found on the 2.4 G systems? (such as model Id, fast data rates and a few other things). I can't for the life of me remember the name of it - it may have been the Royal.

No - just the same problems repeating themselves over and over again.

Yet the digital servos don't seem to have the "boot up" issues.

Would this come under the heading of "Bling" ?

Yet people still lose planes frmo apparent loss of signal with these "bullet proof" systems.

Yet we pay more for them

This is not 100% true - There are line of sight issues (I have seen this at a field where some buggies share the same land area) and with some of the "prepackaged" 2.4 Tx's that were released in some foamies in China a couple of years ago


I'll give you that one

I guess this is why I (and many others) needed to upgrade the power supplies in our JR 12X's (and others). I used eneloops in mine (before you ask) now it lasts for about an hour and a half of flying instead of the 25 minutes it lasted with the original pack.

Really? - apart from frequency control issues (perhaps). I don't se huge differences that couldn't also have been implemented to 72 MHz.

Yes, I do fly 2.4 and I do appreciate many of the advantages of the radios (programming, les hassle over aerials and a real good bling factor) but I am not totaly convinced that it is the "be all and end all" "Must Have" that many make it out to be.

But of course, that is my opinion - there are others

dirtybird

My Feedback: (5)

Other people must have a different opinion. The market for 72MHZ has practically disappeared in the US

nonstoprc

My Feedback: (90)

72mhz radios/receivers are not favored because RC pilots want a better way to protect the investment in airplanes, engines, air-boarn control systems etc. 2.4G equipment can meet the requirement to a great extent.

Rv7garage

My Feedback: (10)

All I know is from personal experience with a DX6i; that i was locked out twice for several seconds, these 2 lockouts occuring on different days- both times with fresh 3S lipos, BEC running @5.5V from a Castle Creations Phoenix 35 ESC, and the loss of link occuring @ the beginning half of the flight. No radical maneuvers, no high-drain situations... just unexpected lockout. In other words, I am 100% positive that the receiver setup and battery situation were good.

From my perspective, Spektrum products are good for foamies and nothing else. I have scale glow models that I have spent more than a year building, and would never in this lifetime use a Spektrum/JR radio in them.

Seems like people who bought into the Spectrum brand get pretty darn defensive when someone has the gall to criticize the brand. I guess I'd be a little embarassed too, if I purchased a needlessly complicated, less than reliable technology. I know, I know- the 10:1 crash ratio evidence is mostly anecdotal. But for my peace of mind, it's FHSS/FASST. Never had a problem, don't expect to.

Just my 2 cents; please feel free to keep all indignant responses to yourselves

wildnloose

The title of this should be Futuba vs JR.

Futuba uses fhss/dsss hybrid, JR does not use true dsss, so what is the point??

Oh and I agree with this:
In this case, why not just go to the best, Weatronic...

Riddle me this, in the past we used to hear about hits, now its replaced with lockouts. Most guys in this hobby have no clue on how to set up their power system. Heck I know guys who flew for 30 years but do not know about aileron differential. Now, I don't know anyone here, so I am not making accusations, nor am I trying to talk about anyone here. I am just stating the obvious (like many have mentioned in regards to their experience of Spektrum vs Futuba in the field).

I don't play brand war. I originally picked JR because it felt the best in my hands (I looked at Hitec, Futuba, Airtronic). I continue to fly JR/Spektrum because I want to. I could care less what anyone has to say, good or bad. Normally I would say that I will continue to fly JR/Spektrum until I have problems with it, but I must admit, the Weatronic system has my attention, and there is a good chance I will switch to it next year.

I just tell people to get away from me because they do not know what they are talking about. I have been in the RF field for the last 20 years, work for a company 15 years (as a RF Engineer) that built a "true dsss" system from the ground up (55+ million customers, I am personally responsible for about 2.5 million) and do not care to hear what someone googled (or Wikepedia if that is your preference) last night.

Last, be glad you have choices. I am, and I would like to keep it that way. There is no need to justify your choice, fly what makes you feel good.

Getting off my box now...

dirtybird

My Feedback: (5)

You cannot be 100% sure of your battery system if don't have a recording of the voltage during the flight. You also could have a mutipath situation at your field.
I don't have a Spectrum system but I don't think it is less reliable than FASST.

nonstoprc

My Feedback: (90)

Even Futaba combines fhss and dsss, its main scheme is fhss. dsss is used within each hopping frequency.

Weatronic is pure fhss? Is it better than hybrid fhss and dsss?

An interesting comparison of fhss and dsss can be found [link=http://rcmodelreviews.com/fhss_vs_dsss.shtml] here [/link]. To quote:

"What about large events such as SEFF and Joe Nall, where there can be dozens or even hundreds of people all trying to use the 2.4GHz band together? Which system provides the most protection against lockouts or getting shot down?

Well all-else being equal (which it's often not, thanks to sub-standard power systems, and poor installations), the FHSS system should have an edge over the DSSS system when it comes to retaining control of your model.

As my own tests have shown, when a DSSS system like the Spektrum encounters strong interference on its two operating channels, it loses link and control is lost. Sometimes, if you're unfortunate enough to have your system select two very closely spaced parts of the band, your system can fail, even though the other 80% of the band is completely free of interference.

By comparison, all of the FHSS systems I tested showed their ability to continue working even after 80% of the band was saturated with interference and only a small portion was free.

So, in theory and in practice, a good FHSS system will keep working long after many 2-frequency DSSS systems have locked out.

However, that's not the whole story.

Because the FHSS systems are using much (or all) of the band, there are situations where they can be badly affected while a DSSS system is not affected at all.

This can occur if the band is heavily congested except for a small portion and the DSSS system chooses that portion on which to operate. It's signals may be allocated to the clean part of the band and thus provide faultless communications, while the FHSS one loses a good percentage of its data to noise because it's hopping through interference.

Experience shows however that this scenario is far less likely than the converse one, where the DSSS systems shut down while the FHSS ones continue to provide a measure of control

If you look at the anecdotal evidence from large meets such as SEFF and Joe Nall it becomes apparent that there were far more "issues" and radio-related crashes associated with the Spektrum DSSS equipment than with FHSS systems of other brands. Now this will be at least in part due to the popularity of the DSM2 system and hence the more DSM2 radios in use, the more they'll be represented in the crash statistics.

However, it's still very clear that DSSS systems are less tolerant of very noisy environments than FHSS systems and lockouts are more common with Spektrum/JR than with FASST and other hoppers.

I'm sure that Horizon would say "there were hundreds of DSM2 systems at these meetings yet only a very few experienced radio issues" to which I would ask in reply "the DSM2 flaw I discovered only occurs with about the same regularity - could these crashes have been related to that problem?"

The Bottom Line
It strikes me that, as the 2.4GHz band becomes more congested with RC fliers, the number of problems being experienced by DSSS fliers seems to be also increasing disproportionately to the number of those systems in use.

Theory makes it clear that a constantly agile system (FHSS) should be more resilient to noise on the band and this seems to be born-out in practice.

If you've got a DSSS system and had no issues then don't rush out and swap it for FHSS just because of the small theoretical and practical extra level of insurance it may offer.

However, if you're looking to buy a new RC system, think carefully about the benefits FHSS might offer before committing to a system (DSSS) that is quickly losing favor in the RC marketplace (even JR is switching to FHSS elsewhere in the world)."

TimBle

People I know who have used Weatronic have run away from it and opted for F or H.

One fella said it was the most unreliable system he ever had the misfortune to own.

On paper its good but it needs a lot of bugs ironed out.

wildnloose

I am looking for this kind of info, care to give details...know where I can look to find it. So far, I cannot seem to find the complaints...

wildnloose

You still cannot classify it as only fhss. Nor can you specify Spektrum as dsss only. The systems I work with every day are not designed the same. A more accurate comparison is faast vs dsm2...

Did not say what is was, so what is your point?? Who cares, I don't. I said it was the best, reply to that.

Again, I don't care. I never pointed out to one vs the other, why are you still on this??

I never said anything about anyone being shot down for any reason, why are you bringing this up in response to me?? Let me say again, I don't care, I will continue to use my JR/Spektrum setup as long as it works. When it stops, I will lood for something else. I am still leaning towards Weatronic.


I still don't care.

In case you did not read me several times before, I don't care what your results are. No need to beat me down with it. As long as you are happy with your decision...

I hope you are glad to get that off your chest. Still, I don't care...bye bye now.

xlr82v2

My Feedback: (1)

Hehehehe!

All the while, 72Mhz remains quiet, rock solid, and getting more wide open. And, I have a nice long antenna to hang my wind flag from.

I think I'll stay right where I'm at, and let you guys continue to figure out by attrition "what's best".

TimBle

well its not written down anywhere but lets just say that someonesponsored a few guys with Weatronics to get it into a market. Those pilots then se the system and everything was great until some hardware issues cropped up that resulted in telemetry causing problems with radio link security and a few planes were lost. Maybe those bug have been ironed out by once bitten twice shy.

pilotpete2

Do you realllllly think all those "retired' 72 Mhz systems are being dropped off at the recycling center, or dumped in the trash???
Coming soon, to a park or school yard near you, or your field
It's happened at our field.
Pete

PlaneKrazee

My Feedback: (14)

We've had 2.4 shoved down our throats. There was no problem with 72mhz. In fact they could have made diversity 72 mhz or frequency hopping 72 mhz and or tx's that wouldn't transmit if the channel was busy. The fcc wants 72 mhz band and companies want to sell new equipment.

As far as DSM vs. Fast and other hopping, JR in Japan uses hopping NOT Horizon/Spectrum DSM! At the Noll there were several pilots that had to "rebind" the Spectrum equipment. Me guesses it's because thier two channels were busy.

slarty

That would be because the Japanese authorities do not recognise DSM2 as a hopping system and limit it to 10mW. DSMJ uses the same hardware as DSM2 but with different firmware loaded.

JR have released their own 2.4 GHz system called DMSS recently.

TimBle

have a look at www.rcmodelreviews.com

He demonstrates how JR FHSS is superior to their DSSS..

Zor

I encorage all readers to take time and read attentively this review.

There is a good clue of what I wrote about the possibility of a strong interfering signal being the cause of a random (freak) bind indicaton on a Spektrum receiver.

Note, please, I am no saying there is a bind. There may be one or there may not be one but there certainly was a bind "INDICATION" .

If such was the reason as discussed in the review, it is quite logical that it may never show up again in a long time or ever.

Of course some fellows may never experience the situation.
They might even think we are crazy, imaginative, dreamers and are inventing things which we (who reported the experience) are not.

I have seen postings indicating that the writer had not really followed the history of the reported malfunction and kind of ridiculed those who reported the malfunction.

Hey . . . gals and guys . . . is your chimney supersonic proof ?
Santas jet is being readied for take off at 07:00 AM EST ( 12:00 UTC ) on Friday the 24th.
From the date line in the Pacifc ocean he covers the whole earth in 24 hours, comes in all the chimneys of those who were good kids in 2010.

Enjoy whatever Santa puts in your stocking.

Zor.