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Old Aug 20, 2009, 05:41 PM
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USA
Joined Sep 2003
967 Posts
Thank you.

You've done more to define your lack of understanding of the SS 2.4GHz process(es) than I could ever have elicited. Whether it be DSSS or FHSS.
No further comments from me will be necessary.

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Release after release after release after release. All to address shortcomings in product line that was rushed into production to maintain market leader status.

Bind & Fly? Another 'reason' to choose Horizon product. Just disposable trash that makes a killing on margin.

Watch JR defect and Horizon / Spectrum spin the news any way possible to keep customers calm...

JR has developed a Freq-hopping 2.4 protocol and WILL go that way; just watch. Sure they'll say it's for a 'foreign market' or some other damage control BS but it'll happen.

Why?!?!

Because Spektrum air DSS was always a half-baked product that was not ready for primetime.

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Old Aug 20, 2009, 06:27 PM
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richard hanson's Avatar
United States, UT, Salt Lake City
Joined Oct 2007
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Quote:
Originally Posted by FrogChief
Good post Adrian:



Seems he'll latch onto anything that confirms his views...

Doesn't matter that us sailplane guys regularly range out further than most and need 110% performance from our gear. We're HARD on our gear and find weakness very quickly.

One good reason why Spektrum released the 'carbon fuselage' AR6250 Rx, because they were caught with their pants down.

Release after release after release after release. All to address shortcomings in product line that was rushed into production to maintain market leader status.

Bind & Fly? Another 'reason' to choose Horizon product. Just disposable trash that makes a killing on margin.

Watch JR defect and Horizon / Spectrum spin the news any way possible to keep customers calm...

JR has developed a Freq-hopping 2.4 protocol and WILL go that way; just watch. Sure they'll say it's for a 'foreign market' or some other damage control BS but it'll happen.

Why?!?!

Because Spektrum air DSS was always a half-baked product that was not ready for primetime.

At least thats the way some see it...
Spoken like a true expert on being half baked.
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Old Aug 20, 2009, 06:40 PM
Registered User
USA, CA, Merced
Joined Dec 2007
504 Posts
jebus guys, can you all tone down the vitriol a notch or 5?
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Old Sep 06, 2009, 04:28 PM
petrol head
queensland australia
Joined Sep 2007
32 Posts
howdy same post as another thread

as you know my faser punched in due to lock out not bad air or pilot error, but it could have been anything else eg switch, battery, rx position, im going with the faser on rx orientation, i now know it was a bit Sus in that plane, my fault >

it was cramped in and i wasn't real happy with the way i positioned the aerials, it was a AR7000, i have now bought a AR9300 and will buy another one for my xperience pro.

i have had a few lockouts with my foamies, 4 cell eneloop batteries, good switch system, but there is better to which i might change to, but i think the main reason for lock outs with my foamies is the aerial is all on one plane in the wing, AR500.

i have never and i say never , touch wood had a lock out with any of my electric planes ;D ;D, may be because it's lipo?????
or a better connection for the power????? constant voltage?????
my electric use AR7000

when my skua was doing thermal turns all on its own at about 200 feet(lock out) i turned the tx off and it then immediately went into a dive and punched in, why did it respond to no tx but wouldn't respond to my tx imputs???????????? :-/

im not here for a debate i just want to tell you what has happend to me

regards nick
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Old Sep 06, 2009, 05:27 PM
The reviewer
XJet's Avatar
Tokoroa
Joined Mar 2004
3,827 Posts
Quote:
Originally Posted by bluezuki
i have had a few lockouts with my foamies, 4 cell eneloop batteries, good switch system,
It is *not* good practice to use 4-cells with *any* 2.4GHz radio, especially Spektrum, which has a higher reboot voltage than most.

You really should use 5-cells or a 2S A123.
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Old Sep 06, 2009, 06:08 PM
slow but inefficient
Ron Williams's Avatar
Riverhead NY USA
Joined Dec 2000
3,097 Posts
On the matter of JR/Spektrum vs. Futaba, here's a story involving a very well known RC modeler who had discouraging experiences with both. First, in late August at a funfly, attempting to launch a plane with Spektrum, the plane failed to respond on two successive occasions. When it was picked up after each attempt the radio worked fine.

This modeler's reaction was to switch to the Futaba system for a large twin engined scale model (24+ lbs.) and set the Spektrum aside. On its second or third outing FSSS went South and the plane went East crashing such that it was beyond repair. The modeler goes unnamed here because I don't want to name him without his approval. He's one of the most knowledgeable regarding RC and electric flight that I know.

Needless to say, there is a lot of disappointment with both systems and confusion as to how to handle the situation of neither system being completely satisfactory and reliable.
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Old Sep 06, 2009, 06:32 PM
petrol head
queensland australia
Joined Sep 2007
32 Posts
thanks Xjet
You are right, and i will be putting five cell in ALL my planes from now on

regards nick
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Old Sep 07, 2009, 08:56 AM
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Joined Aug 2008
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I use 4 cell nimh rated at 2000 mah, and not a single problem. These packs can probably fly for hours, but I usually charge up often. My question is: what is the maximum drain the battery can have on a spektrum 2.4 ghz system if there are 4 std servos? If I knew this, I could set my discharger at that rate and test my batteries for the worst.
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Old Sep 07, 2009, 09:41 AM
60 years of RC flying
Daedalus66's Avatar
Canada, ON, Ottawa
Joined Feb 2006
16,507 Posts
Quote:
Originally Posted by lucasavaitor
I use 4 cell nimh rated at 2000 mah, and not a single problem. These packs can probably fly for hours, but I usually charge up often. My question is: what is the maximum drain the battery can have on a spektrum 2.4 ghz system if there are 4 std servos? If I knew this, I could set my discharger at that rate and test my batteries for the worst.
You're not going to get a simple answer to that question. It's the momentary spikes of current that cause the voltage drops that kill the receiver, and they are hard to measure reliably. The best one can do is to note from general experience that while 4-cells usually works OK (I've flown that way lots of times without any problems) 5-cells gives an extra margin of safety.

My own plan is to use 5-cells from here on (or 2s 123 with regulator).
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Old Sep 07, 2009, 09:45 AM
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pilotpete2's Avatar
The Northeast Kingdom, Vermont
Joined Jun 2004
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Why mess up the best battery you can use with a regulator
A 5 cell Nixx is hotter off charge than a 2S A123
Pete
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Old Sep 07, 2009, 09:47 AM
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Joined Aug 2008
1,015 Posts
I definitely see the point here, had I known more about rc when I purchased those batteries, I would have got 5 cell. I'm guessing 2.5 amp absolute maximum draw (worst case situation) for 4 standard servos. In my experience, 4 cells not only works, it works well.
Quote:
Originally Posted by Daedalus66
You're not going to get a simple answer to that question. It's the momentary spikes of current that cause the voltage drops that kill the receiver, and they are hard to measure reliably. The best one can do is to note from general experience that while 4-cells usually works OK (I've flown that way lots of times without any problems) 5-cells gives an extra margin of safety.

My own plan is to use 5-cells from here on (or 2s 123 with regulator).
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Old Sep 07, 2009, 09:54 AM
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Julez's Avatar
Germany
Joined Dec 2003
5,331 Posts
Quote:
Originally Posted by XJet
It is *not* good practice to use 4-cells with *any* 2.4GHz radio, especially Spektrum, which has a higher reboot voltage than most.

You really should use 5-cells or a 2S A123.
Why not?

Systems like Fasst or Jeti would even work with 3 cells, so why not use 4 cells?
Heck, I even fly light planes on a single LiIon cell.
Just because Spektrum and XPS have a high reboot voltage, and synchronize the servo load, it does not mean that all 2.4 systems work that way.

http://www.rcgroups.com/forums/showt...8#post12913918
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Old Sep 07, 2009, 05:11 PM
The reviewer
XJet's Avatar
Tokoroa
Joined Mar 2004
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Quote:
Originally Posted by Julez
Why not?

Systems like Fasst or Jeti would even work with 3 cells, so why not use 4 cells?
Heck, I even fly light planes on a single LiIon cell.
Just because Spektrum and XPS have a high reboot voltage, and synchronize the servo load, it does not mean that all 2.4 systems work that way.

http://www.rcgroups.com/forums/showt...8#post12913918
Yes, under ideal conditions 4-cell will work fine, especially with the many receivers that will work down to around 3.2V or so (Corona, FD, FlySky, FASST, etc) -- but what happens when things go wrong?

What if you have a servo failure that places a heavy load on your battery (blowing both sides of a H-bridge FET output will do that) or if you get a jammed rudder servo due to flutter stripping the teeth?

Suddenly you have a sustained heavy load that can cause significant voltage drop due to the battery's internal resistance, switch resistance and even the resistance in the battery leads/connectors.

A 4.8V pack (even on a low-voltage receiver) may have a couple of volts of headroom -- but a 6V pack will have 50% more.

Then there are the failure-modes for battery packs -- sometimes a cell will go short-circuit. With a 4-cell pack, that brings you down to a nominal voltage of 3.6V -- only .4V above the reboot voltage of many receivers and down to a point where your servos are suffering from greatly reduced torque and speed.

I recommend 2S LiFePO4 packs (a solid 6.4V for 85% of the discharge cycle) or a 5-cell NiMH pack simply because they buy you some extra insurance that you may never need but you will certainly appreciate if it saves a model (one day).
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Old Sep 08, 2009, 04:44 AM
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Julez's Avatar
Germany
Joined Dec 2003
5,331 Posts
Well, if one has a shorted servo, the current it draws depends on the voltage supplied.
A 5 cell pack will have a higher voltage, but that also means a higher short circuit current in return. And a higher current means more voltage drop across the several resistances you mentioned. So I doubt there will be a real advantage with more cells.

Concerning the shorted cell:
http://www.rcgroups.com/forums/showp...8&postcount=77

Nevertheless, all your arguments are valid. But I do not see the reason why they particularly concern 2.4GHz systems.

Well-designed 2.4GHz systems do not have more problems with low voltage than MHz systems.

If you say, that it is generally a good idea to equip RC planes with 5 cell batterys, I would be the first to agree.

But I do not agree with the generalisation that 2.4GHz systems are more prone to problems relating to low supply voltage compared with MHz systems.
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Old Sep 10, 2009, 08:16 PM
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USA, GA, Holly Springs
Joined Feb 2007
108 Posts
Still Flying 72Mhz!

I have been flying for over 30 years and still fly 72mhz. I have never had a problem (ie. CRASH!!!) I could not contribute to my own stupidity! Of coarse dumb thumbs plays a large part but I have had a radio failure or two! Once I was flying a Super sportster 40 straight and level. Suddenly it snapped and went in from about 40 feet. After careful inspection of the wreckage we discovered the receiver switch had disintegrated from the inside. It turns out the smaller mini switches most radios come with can not handle too much vibration. Of coarse I had mounted the switch in the side of the plane for easy access. This I attest I will never do again. I have also had a fellow flier switch on his radio without checking the frequency board. A new-be and we have all done this at least once. This is the type of error that can not happen with 2.4Ghz radios. Essentially they have made the radio a lot more stupid proof!
This is progress and fine with me, but I have a lot invested in my radios and although they do not owe me anything (my Galaxy 8 is almost 25 years old) I love the feel of them. I am still flying helis with the Galaxy and my planes with an 8103DT. My son and I take our pins early in the morning and rarely have to give them up all day. Thank you to 2.4Ghz. We will bay a Spektrum soon but for now we will fly on 72!

Causality is the Root of all Life!
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