2.4GHz vs FM - Which is best

[h3li]

Hi Guys,

Any major considerations when choosing one over the other?

Whose running with the new Spektrum Tx and Rx combination, versus conventional FM, and the long retractable Tx antenna?

I've read of intermittent issues with the Spektrums, along the lines of sudden loss of signal between Tx and Rx!? This is more of an issue with Heli's - planes should just glide down with less chance of damage.

Also, am I right in saying that an FM outfit will provide further range (distance that the Tx and Rx can still communicate)?

On a down side, FM is more prone to interference....

All feedback appreciated

[Smoothound]

2.4Ghz

It dumps on FM of either flavour.

I've yet to have any issues with my Spektrum setups, no lockouts, no brownouts, no interference etc.

The only down side for me is that it is a bit of a pain to fit inside some smaller planes due to the size of the Rx's or carbon fuses

If you are buy a radio for the first time its a no brainer

[moyesboy]

The biggest advantage of 2.4Ghz is no need for frequency control. The transmitter looks for free frequencies to lock on to the rx - so you are not concerned with other people switching on within range of you - be they other pilots who haven't correctly followed pag board precedure, or some kid rond the corner with a rc model in his bedroom or garden.

I flew my 450 and 50 size helis with PCM 35mhz and never had a problem with any glitching on the larger heli. The smaller electric heli was a problem so I changed to 2.4Ghz spektrum DX7. Since then I have never had a problem with either. If you are considering a small electric then I strongly recommend 2.4Ghz - either futaba or spektrum, I only have experience with spektrum.

There have been a few problems with the trex500 mainly for some reason to do with static discharges (the belt charges up). It seems they have found a cure involving earth straps. For some reason this hasn't been reported on the smaller 450 or rthe larger 600 electrics despite similar mechanical construction.
Other problems with the spektrum have been lack of continuity in the receiver power supply. IF the power dips to the receiver then it takes a long time to reconnect with the transmitter. The newer spektrum receivers cured that with a quick reconnect software upgrade, so provided the power comes back to your receiver then it will pick up immediately. My recievers don't have the new software and I have yet to expeciance any issues with this.

Generally 35mhz receivers are not as susceptable to low voltage on the power supply - but of course all receivers will fail if the rx battery goes flat.

I have a UK spec spektrum. This is lower transmitter radiated power than a US spec. however there is no problem with range for flying a heli or any other model except perhaps a large glider as they tend to be flown the furthest distance away. Carbon fibre in the fus of large gliders is another problem as the samll 2.4Ghz antennas end up inside, while the 35 mhz antennas can be routed outside. Carbon is conductive and blocks the signal.
You never fly a heli very far away, even 90 size helis are only average fixed wing size and you need to be able to see what they are doing more precisely!
There has beena lot of talk about this lower power, but spektrum say that the range is still out of sight on the lower power, and there have been no reports that I have seen about even large models going out of range with the full range receivers with 4 antennas (or more).

If you have more than one model then the spektrums model match prevents you trying to fly the wrong model for the tx memory. another good safety feature.

I'll not be going back to 35Mhz.

[Ian]

no advantage to 35mHz unless you fly all carbon gliders. 2.4GHz is the way to go, spektrum is my prefered way, never had lock out, brown out, interfereence or anything! gets my vote any day

[h3li]

Thankyou for your feedback. Looking into the DX6i radio combo, being a long range Transmitter, plus the price is very reasonable too!

Another query - Currently, I have a 'basic' 5 channel Transmitter, that came as part of the package, with my Mini Titan.

I've read that using a 4 or 5 channel Transmitter, the Ace Gyro will use 'normal flight mode' on the cyclic / E-CCPM.

However when a 6+ channel Transmitter is being used, aerobatic/3D flight is then possible, as per a program on the Gyro / E-CCPM mixing.

So if I suddently start using the DX6i, will the Hei automatically 'switch' to 3D/aerobatic flight mode, or will I probably have to change a setting on the Gyro, so it "knows" what flight mode to use (dependant upon the Transmitter im using).
It's an AceRC TG6100M E-CCPM mixer Gyro.

If anyone has any experience with this, it would be appreciated.

Cheers.

[marktigere1]

Hi

The DX6i has two modes being Normal and Stunt (also known as Idle Up).

What this simply means is that you can have two different settings for Pitch and Throttle.

For example, normal mode has the throttle being at idle (glow Heli) or Off (Electric Heli) when the throttle stick is at it's lowest position, but when switched to Stunt mode, the Throttle would be 100% to enable 3D and aerobatics.

My DX6i for my Trex 450 has a linear Pitch range of 0 25 50 75 100% set for both Normal and Stunt mode and the throttle is set 0 25 50 75 100% for normal and for Stunt mode the throttle is 100 85 70 85 100%. This allows loops and rolls.

Some people set 100 100 100 100 100% throttle for stunt mode but I prefer a more progressive feel for my flying.

To answer your question, you select when you want 3D/aerobatics from the transmitter.

Hope this helps.

Cheers

Mark

[h3li]

Hi Mark,

Thankyou for your informative post. When it's written in that way it is clear and very understandable, makes alot of sense! Unfortunately I don't know of anyone else that flies Heli's near me, hence alot of my knowledge is either first hand, or from feedback on forums like this one!

Great - So it should just be a matter of swapping out my current Rx for the Spektrum one, connect it up, and it 'should' operate seamlessly, with my existing AceRC Gyro.

The Pitch settings that you confirm are a very useful reference - I'm making notes I will see a whole new side to the Mini Titan once I get the DX6i, as my Tx is very basic with no display, but does the job.

Again, many thanks!

[marktigere1]

No problem

[jboweruk]

Hi Mark,

Thankyou for your informative post. When it's written in that way it is clear and very understandable, makes alot of sense! Unfortunately I don't know of anyone else that flies Heli's near me, hence alot of my knowledge is either first hand, or from feedback on forums like this one!

Great - So it should just be a matter of swapping out my current Rx for the Spektrum one, connect it up, and it 'should' operate seamlessly, with my existing AceRC Gyro.

The Pitch settings that you confirm are a very useful reference - I'm making notes I will see a whole new side to the Mini Titan once I get the DX6i, as my Tx is very basic with no display, but does the job.

Again, many thanks!

Right, I have only Coax at the mo' and heck even then you see a whole new side to them with a dx6i. Honestly mate you can't go wrong. You may see a couple of my posts where I've had issues, but honestly don't let it put you off, I haven't come across a single post anywhere on the www for my issue, and only a couple (literally a couple out of the thousands they must have sold) for any issue at all, which says to me that the dx6i is a fine tx. Hence why mine's away and i will stick with it, even when I buy a new heli (blade 400 has one with that too).

[marktigere1]

I haven't come across a single post anywhere on the www for my issue, and only a couple (literally a couple out of the thousands they must have sold) for any issue at all, which says to me that the dx6i is a fine tx. Hence why mine's away and i will stick with it, even when I buy a new heli (blade 400 has one with that too).

Yep.

Sorry about your hassle with the DX6i. (Hope your getting a replacement?)

I have had no issues at all. Works great with both a Raptor 50 and a Trex 450S.

Cheers

Mark

[Mike W]

Went from 35mhx to 2.4ghz and not looked back since ... No glitches outages or nothing ....Just took a while to not trying to pull the ariel out lol ....

[scallybert]

I like Spektrum kit, but I've had a lot of problems with lockouts, etc. [This is at least partly due to my inexperience.]

I'm pretty sure these have been due to other electrical components having been marginal - such as motors overgeared, gyros &/or servos misbehaving.

Nonethless this has resulted in a fair number of small crashes, and some minor damage. Quite lucky in that respect, but one problem heli was out of action for months as I struggled to find the problem. I struggled an awful lot. (I literally swapped all the electrics.)

You defintely want QuickConnect firmware. Without it, a power glitch can leave you locked out for several seconds. The AR6200 that comes with a DX6i will probably have this. Other Rxs may not. It's a free (return to Horizon) upgrade.

You want to make sure your electircs are 100%. eg servo loading won't make the Rx power drop; components aren't putting spikes on the power; your ESC isn't going to upset its BEC if your motor goes overcurrent.

QuickConnect will help with the above, but isn't a fix-all. I've seen QC AR6200s lock-out, with the LED having a fit.

If your Rx LED is flashing when you land, you want to look at your electrics.

There's a Spektrun 'power protector' (4700uF capacitor across power rails) that can help.

I think the Spektrum stuff is great, but it's possible to have some 'hard to fix' problems. Even if you're an old-skool IT guy with an engineering degree...

[Luis Corales]

hi, i use spektrum dx6i... is brilliant so far...

greetings

[LaurenceGough]

Spektrum DX7, far better than FM/AM etc. No problems whatsoever! No glitches and a bullet proof link.

[scallybert]

I've just succesfully run 3 batteries through my 'problem heli' from a few posts back, so I'm well pleased. (DX7, AR6200(QC))

It's great I'm the only person here that seems to have had problems, but there's a reason that they implemented QC, and sell the big capacitor - and I'm sure it wasn't because no-one had lock-up problems.

Spektrum kit is great, you just have to be aware that it can be sensitive to some things.