dado0099

Hi,
I just bought the above radio (new) to run an old tamiya hilux with electro-mechanical speed control.
The problem is this:
When the motor is stopped everything works fine.
When the motor runs all the three servos are moving randomly (glitching ?).
I thought that could be a noise suppression problem and I fitted three 1mF capacitors to the RS 540 motor,
but it is the same.
I tried also to move receiver and antenna around but with no success.
I tried to spray with cleaner all the contacts and again no success.
I have noticed that the receiver is very sensitive to any kind of interference,
for example if you touch with a metal part the power supply line both of the receiver and of the motor,
the servos starts glitching for a while.
Do you think I have a defective receiver ?
Or what else can I try ?

Thanks

MikeMayberry

My Feedback: (1)

It could be the ESC or the RX crystal.

Mike.

bogordoug

With the motor running you may be putting too much current drain through the receiver which will cause glitching. We have experienced this problem when combining an RMG Sailwinch with servos greater than the standard supplied with a radio. Changing your wiring so the power goes directly to the esc and motor with only signal connected to the receiver. You will also need to provide the receiver with power.

dado099

Thanks bogordoug,
but I already have the receiver powered separately from the ESC.
Thanks Mark,
I tried to bypass the esc connecting directly the battery to motor and as soon as the motor runs the glitching arise again.
I'm always suspecting a fault in the receiver (or transmitter ?).
What else can I check ?
I can tell you that I tried an old Futaba and Airtronics radio on 72.150 Mhz (AM) and with both, the servos are rock steady.
I'm worried to run the truck in this condition !

dado099

Hi Mike,
just a curiosity:
I noticed that the antenna wire on the receiver is very short compared to other brand's receivers, how much should be long (75Mhz) ?
Thank you.

dado099

Hi Mark,
I noticed that receiver's antenna is very short compared to other brands, how much should be long (75Mhz) ?
Thankyou.

MikeMayberry

My Feedback: (1)

23"

dado099

Thanks.
Another update:
I noticed that using nicd batteries instead of alkaline for the receiver slightly improove the number of interferences.
How can it be possible ?

Thanks

MikeMayberry

My Feedback: (1)

That should not affect the reception.

Mike.

dado099

Just to help other people:
I found a definitive solution:
I opened the receiver, soldered a tiny shielded cable in place of antenna wire, grounded the shield and ran the cable away from receiver. I soldered the original antenna to the end of the shielded cable.

IT worked GREAT !