3905 Emaxx, with Neu setup bizarre reception problem
 

Hey guys I'm running a new setup that arrived this week that I was testing tonight. I'm running a 3905 Emaxx with a Neu 1521 1.5D and HV110 on 10S. The truck has insane amounts of power, but horrible reception. Everything is still stock as far as radio and reciever is concerned, and I'm running the Castle BEC. Here is my big problem. When I got the truck together with 4S my reception was great, then I moved up to 6S and the reception got shorter, then I jumped up to 10S and the reception is maybe 40-50ft max. Why is the reception getting less as the voltage goes up. Does the Castle BEC suck, or do I need a new ESC?? I tried seperating all wires away from each other, but that still doesn't explain the fact as the voltage climbs the reception shrinks. Does the BEC voltage need to be boosted up to 9V instead of the default??

Could it be the stock radio giving you trouble?


Promod

Why would the range drop dramatically as the voltage climbs? I swap back to 4S and the range is long distance again???

the ccbec is only good to 6s lipo. This may be some issue. Your factory am radio system may also be causing some problems.

Correct, but I'm running it off the series connector which only pulls the votlage from one side only. So its seeing only 5S max or 3S or 2S depending on the batteries I'm using.

could be a defective ubec, happens from time to time

Checked it a few mins ago and its putting out exactly 5.00 V's.

I'm sure this will get slapped. But what the... If you are providing more voltage available to the motor and esc. I thought I read that they will take as much as the battery will provide. So wouldn't that also mean that more voltage is going through the wires connecting the batteries esc etc. The insulation on the wires is the same but the voltage is increase so more harmful radiation is escaping into the atmoshper destroying the ozone. Seriously I don't know what is called. EMF or something like that. So more voltage, same wires, more emf as voltage increases creating more interference.

I'm confused. It has to be the am radio.

I just tested it by dissconnecting the ESC so the truck won't rocket off. But the steering starts to glitch at around 25ft with 10S lipo. If I step down to a single 2S lipo I can go 200 ft or more. My buddy was holding the truck as I got further away from it and he watched the servo. Also on 2S which is the lowest I have it outputs at 4.95V and at the maximum which is 10S it outputs at 5.05V's. Not sure that would matter though.

If you have a reciever pack try it using the reciever pack and the UBEC diconeected. If it still has the same problem then you eliminated the ubec as the issue. If it works with the Rx pack instead of the ubec then you know its the UBEC.

Yeah just tried the RX pack off an MGT and it works alot better, but the RX pack has limited distance, but its consistent no matter what batteries are attached to the ESC. So the question is what's next. What is the best solution....should I go RX pack, but is their a better one as the MGT one has limited range.

So you narrowed it down the the UBEC. I have heard of some having interference issues with the CC UBEC, but the higher voltage making it worse is a new one. I'm suspecting that the higher voltage into the BEC is causing the BEC to work harder and therefore creating more RF noise and more interference, but I don't really know enough to make sense of that. One of the electronics wizzes around here can probably explain why that would be.

But, to start working on eliminating the problem. I would start with moving the BEC as far away from the Rx as possible and see if that helps. If it doesn't, you might try wrapping the UBEC in a few layers of aluminum foil. this might help shield any noise that its generating from getting out to the Rx. Beyond that I would say stick to the Rx pack, or get another BEC or something.

Do you have the Castle Creations USB programing wire? I would bump that voltage up to 6V if it were me. You will get more out of you servos that way, and maybe the higher voltage will help with the interference issue too. I don't really know why it would, but it seems logical to me anyway... but its probably just me.:tongue:

I just thought of something else, I saw that someone had put a ferrite ring around the wire from the UBEC to the Rx. The ferrite ring helps surpress any noise that the UBEC might generate.

Something liek this might help.
http://cgi.ebay.com/ws/eBayISAPI.dll...m=290210641745

Not really sure if that particular one is the right size, but just to give you an idea of what I am talking about.

I have the BEC on the other side of the truck or rear and the RX is in the front. Still no luck. I just don't understand the higher voltage interference. Guess it does cause more noise in the BEC is all I can guess.

As for the USB, no I don't have it yet, but will be soon as CC is out of them right now.

With that amount to money invested in a motor, esc and batteries I'd look at 2.4 DSM - You could pick up a losi DSM complete system for $80...