G3 5014 Receiver - 35Mhz, Is there a "fix"?

[MrMel]

Hi,

I tried a G3 on my Logo, it was not good (using ferrite rings and all possible help already tested), range was (without antenna) about 9 feet, with antenna but folded, about 15 meter.

Ive later found out that the combo Jazz ESC + Orbit motor + G3 just dont work, and I replaced the G3 with a RDP149 regular PCM receiver and instantly I got super range again.

I have two G3's, tested them both, same result.

Apperently, on my Logo 10 which uses Jazz but another motor (Tango), this problem does not exist, so it must something with the shielding in the motor, or something.

However, Ive seen about cutting the antenna for 72Mhz, but is there something to get the G3 working on 35Mhz? Or is it just something that wont work?

Why is the G3 so sensitive when all other PCM receivers are not?

- Fredrik

[MrMel]

I found a "solution", wrap the receiver in aluminium foil and you will get good range.

Its simply that the G3 is too sensitve for RF noise.

Ive submitted this to Futaba, hope they comes up with a more permanent solution.

[tchavei]

Hi

The G3 Reciever appears to be more sensitive than other Futaba Recievers. I havn't been having any range problems with them but I fly nitro so RF noise is less than on a electric bird.

There is one thing that is probably worth investigating. Robbe (Europe's Futaba Oficial Dealer) made a recall for all 35Mhz G3 Recievers for "reprogramming". As I have one original Robbe/futaba G3 reciever and another "non Robbe" I sent both in (praying they would service them both) but only the robbe one was serviced - I got a note stating it was reprogrammed to the latest flash. The truth is that now the range on the robbe one is better than on the other one despite using the same location on both birds and the same base loaded antennas.

Wierd but worth to check out no?

Tony

[MrMel]

Just an update to this for anyone searching here in the future.

G3 + UBEC's are bad combination, with a RX battery its OK.
I can replicate it without a heli, just power the receiver with a UBEC and watch servo movement, range is lowered about 80%...

Tested both UBEC and Medusa BEC (both 5.1 and 6.0 volts)

So, if you are going to run a G3 on 35Mhz on a electric heli, use a RX battery.

[WillJames]

Thanks for the follow-up MrMel!!

[EricLarson]

Good info:

I have used a Medusa BEC on 72mhz with a G3 no issues. This was with the Kontronik 55 and many different motors.

[Raptor Rulezzz]

MrMel,

What kind of amps are you pulling on the T-600? Are you into hard 3D or something else...

The reason I'm asking this is because someone was telling me that I should be worried about using the R5014DPS (I use the 149DP for know) because I'm pulling such high amps. Peaks of 116amps, averages like 75 amps when I'm really going at it :mrgreen:

Cheers,

Richard

[MrMel]

Do you mean with UBEC or RX battery?

Shouldnt matter what amps you are pulling of you use RX battery.
(Danny Szabo used a G3 in the T600 at 3D Masters, at least so Ive been told by futaba..)

[Raptor Rulezzz]

I mean with the RX-battery, but I guess I just have to mount the G3 receiver and find out... I'm certain it will work, but all the bad talk about it kinda scares me.. :roll:

Cheers,

Richard

[EricLarson]

? I have no idea what amp draw would have to do with the receiver.

I am running a 12S, Actro 32-3, 2000 watt average setup with the Medusa 6V bec powering 9451 Futaba servo's and a GY611 and using a G3 with no issues at all.

I have like 500 flights on my 600 mm Razor with the Medusa BEC, and many different motors with the G3 and no issues.

This is with Kontronic and Castle Creations speed controls. Also in all carbon fiber heli's.

This is 72mhz and STOCK antenna, no whip.

Eric

[MrMel]

This is 72mhz


Yep, I think that is the key :)
as far as I can tell, this issue only applies to 35Mhz systems.

[EricLarson]

Sounds like that is the key.

[MrMel]

As a person that really love solving problems, is there something I can do you think?

Ive tried different UBEC's, different Medusa BEC's, all of them gives the same problem.

I dont need a heli to replicate the problem, so I know thats not an issue.

When connecting the Vstabi and the Computer to the VStabi it gave the same problem, which I been told was due to noisy grounding in the computer.

This gave me an idea, could it be the ESC in conjuncture with the BEC perhaps?
I gonna make a test-rig (already have one that I can use) where I gonna replicate the problem with the Jazz controller, then I gonna replace it with a CC 85HV to see if it helps.

Any other tips I can try, is there anyway to "clean" the power from the BEC?
Ive tried running BEC -> Duralite Regulator -> receiver, that didnt help.

[EricLarson]

I recently had an RF issue on a CC110HV control I found that mounting it in different locations helped quite a lot. I have no issue with it mounted by the motor in front of the heli, but on the bottom about 3" from the RX I could not range test certain directions. I crashed the heli doing an inverted hurricane due to that issue. It was not really the controls fault as I range tested in my standard way, but did not check different angles. I know now.

So far we have been able to nearly mount the Jazz on the RX :)

RF is very much black magic to me. Try the CC, maybe it will be much better in your application.

[MrMel]

Mmm, Ive tried putting the esc far from the ubec and both far away from the receiver, even using extension cables so its REALLY far away (over half a meter).

As soon as I run it from the UBEC the issue occur regardless, seems to be "dirty" power in the UBEC.

Gonna do some testing this weekend.

If only XPS could be done with their 2.4ghz modules, I will buy them in a wim :glasses2:

[DavidH]

Mmm, Ive tried putting the esc far from the ubec and both far away from the receiver, even using extension cables so its REALLY far away (over half a meter).

Extensions will make any kind of RF problem usually worse. The longer extensions just make another antenna to receive RF. If you put any extensions in place I would make sure they have an RF choke installed in them.

David

[MrMel]

It was just for testing on the bench, didnt even have the items placed on a heli, just to test if its related to distance between components.

As soon as I replace the UBEC with a RX battery the issue went away, even if the UBEC still was attached and powered, just not running the receiver on that power.

So I belive the noise is carried inside the cable, in the power.

Ive tried with Ferrite Rings without luck, is there any filters out there where connect in one end, and out in the other?

[andersnorlin]

It was just for testing on the bench, didnt even have the items placed on a heli, just to test if its related to distance between components.

As soon as I replace the UBEC with a RX battery the issue went away, even if the UBEC still was attached and powered, just not running the receiver on that power.

So I belive the noise is carried inside the cable, in the power.

Ive tried with Ferrite Rings without luck, is there any filters out there where connect in one end, and out in the other?

Medusa research has opto isolators
http://www.medusaproducts.com/Other/opto001.htm

[MrMel]

Thanks!

Gonna order one and try to see if that helps.

[MrMel]

I think I have found the "cause".

It has to do with the proximity to the Servo's.

If the receiver runs on UBEC the receiver must be further away from the servo's then if I run it from RX battery.

On the Logo 14 with the VStabi I dont have that much of an option where to place the stuff, so Im "screwed" I guess.
But thats also why it works for me with RX and not UBEC.

Wrapping the RX in alu foil worked, but thats no good solution, specially on a electric carbon heli :)

Thats why I experience it, while others might not.

Any takers on a possible fix?

[my64]

I think I have found the "cause".

It has to do with the proximity to the Servo's.

If the receiver runs on UBEC the receiver must be further away from the servo's then if I run it from RX battery.
....


Hello,
Have yo tried to put a ferrite ring between the UBEC and the receiver ?
Olivier

[MrMel]

Yep, even tried two, no dice.

[MrMel]

Futaba 9650