MFC-01 funny sound effect

[ncex888]

Hi, I am new to the site.

I have installed a new MFC on my R620. However, the sound effect does not work some how.

This is my problem:
Engine starts sound fine, idle sound is fine. But once I try to throttle up (not matter what level), it will give a high pitch tone. Even i turn the volume down to minimum. If I have the motor disconnected, there will be no high pitch tone. I seem if the motor is connect and starts to draw current, then the high pitch tone comes on.

Any Idea?

I am using Futaba 4YF 75MHz Radio and Futaba R168DF receiver.

Thanks in advance.

[McFig]

Couple of questions.

1. You are using the MFU for Tractor Trucks, or the MFU for Hi-Lifts?

This is the one you should be using: http://www.tamiyausa.com/product/item.php?product-id=56511

2. What motor do you have installed?

[ncex888]

Yes, this is the product I have for my R620 tractor truck.

The motor is just the stock motor 540.

The sound just come out when the build in ESC start to have loading. If I disconnect the motor, there is no problem, sound effects are good.


Thank for the help...

[McFig]

Ummmm. Did you get the MFU used or new?

[ncex888]

I get it new from ebay.

The funny thing is the high pitch tone also come from the MFC unit itself... even I have disconnect the speaker, NO SPEAKER at all.

I have managed to eliminate the high pitch tone on the speaker (adding a crossover, only allow low frequency signal to reach the speaker).

But the tone from the MFC, I have no idea where it comes from. I have a bit of electronic background, never see that before. Usually chip don't make noise!

I think more likely it is a defective unit.

[McFig]

Its starting to sound more and more like it is a bad unit, I'm sorry to say.

If the e-bay seller is a store, I would try and contact them and see if they will replace it. You can also try Tamiya. Not sure who you should call from Canada.

[janderson]

Sounds like a bad unit contact borgfedt of Canada or the purchase place for repair/replacement

[ncex888]

I am contacting the seller now ... and hope to resolve this soon...

Thanks

[Mouton]

While this may be resolved by now, I would say maybe there never was a fault in the first place.

I think that the high pitched sound ncex888 refers to is the normal sound most brushed ESCs generate during use. It fits the description perfectly and is called the drive frequency. How audible it is depends on ESC/motor combo, but I have heard if from all MFC-01 tractor trucks I have seen in real life over the years. It is not disturbing but audible with the speaker volume set low or off.

What did your dealer/distributor do to address your problem and has the noise dissapeared?

[ncex888]

Thanks for the reply. I did noticed it also happen on other tamiya esc, not only the MFC product. So, that I think it is normal. I just turn up the volume...