One Possible CP glitch solution

[Warren]

Came across this

http://www.rcgroups.com/forums/showthread.php?t=570417&page=2&pp=15

go down to the bottom of the page - he refers to this

http://www.horizonhobby.com/Products/Default.aspx?ProdID=RVO1010

which he claims solved his probs :)

gonna try it - nothing to lose ( except that damn glitch )

[Warren]

f.y.i.

I used a variation of the straw technique mentioned in the previous article link - I have a plastic tube that runs out the back of my superskids - I ran the antenna wire straight down to the tube - straight back until it was behind the rear skid mount, and then wound it around the tube all the way out to the back of the tube with about 2 inches hanging free -

I used small plastic "quick ties" to hold it as I went along the skid and tube - since I have done this ( gotten the majority of the antenna away from the electronics ) there have been no servo twitches - no heli glitches period...... I have had about 3 days ( between rain ) to test it out - seems to have cured the prob :)

[cgroves]

Yeah, the antennas we use really like being as straight as possible and away from any RF noise, metal, carbon fibre, etc.. Thats why on my Nitro birds I run the antenna straight from the nose to the tail via the skids (but not right against the skids). Never had a range problem with that setup. With your antenna the way it is now what are your range checks at? How long were they before?

[Warren]

my skids are ( I think ) some alloy based material, the braces are carbon, or carbon like - anyhow this is why I wasn't too concerned running the antenna down beside them - I have located some rfi copper shielding tape if all else fails - how do you keep the antenna away from the skids ?

as far as the range goes ( I don't see how it would be worse than having the antenna wrapped around the skid assembly ) - I don't really know - I'm still a beginner, so 15 or twenty feet ( in any direction including up ) is good for me :)

[Warren]

Don't know what I was thinking - the antenna tube runs bout half way up the skid platform - not along the skids - :)

One other thing that I did, was wrap the antenna from the 3 in 1 down to the tube in "tin foil" - I figure way up there it isn't actually piking anything up just transferring it - and as I mentioned - no twitches, no glitches -

next step - base loaded antenna :D

[cgroves]

Range checks are really handy, even if you are always flying well within your max range you can tell if a change is making things worse, or better. It also may warn you if your crystal or Rx is going bad on you before it costs you the chopper. It may also tell you that someone else is turned on on your frequency nearby, but is not a substitute for a frequency board. Just try collapsing the Tx antenna and see how many paces away you can get before the heli twitches. I don't fly my Nitro birds unless I can get to 100 paces and my micro electrics 50 paces. I suggest disconnecting one of the motor leads so it doesn't jump into the air on you. All radio manufacturers include range checking proceedures in their manuals.

There are two things you are fighting:
1 carbon, metal, etc reflecting and distorting radio waves from your transmitter so you want to keep your antenna out of their radio shadow. Shielding doesn't help with this, it makes it worse.

2 Antenna picking up RF noise from metal-on-metal vibration and power electronics. This can be helped with the use of shielding, ferrite rings, and placement. Things like having a setup similair to Nitro choppers which have a hot and a cold side (Exhaust and header on one side, fuel, and electronics on the other), run the antenna down the side opposite the esc and away from the motor since those are your two biggest sources. Wrap the ESC->Rx lead around a ferrite ring to prevent RF noise from arriving at the RX from the ESC. It is usually better to shield the source rather than the antenna since shielding the antenna makes problem 1 worse. Antennas have a *much* higher gain when their exposed length is straight and close to roughly 1/4 of the radio signal wavelength.

[Warren]

Thanks for the good info - any chance you could expand on this - -

"Wrap the ESC->Rx lead around a ferrite ring to prevent RF noise from arriving at the RX from the ESC. It is usually better to shield the source rather than the antenna since shielding the antenna makes problem 1 worse. "

Specifically - Wrap the ESC->Rx lead around a ferrite ring - sorry 'bout this - are we talking the antenna into the ESC unit on the heli
( I guess we must be )
- it's the "ferrite ring" bit that I am unclear on......

is this not some form of magnet ( is this a doityourself piece of hardware, or something that can be purchased maybe ) - I didn't think that magnets and electronics got along to well.............

I'll pound my head abit, and see if becomes clearer :)

thanks for the tips - ( like to tinker )

Warren

[Warren]

Thanks again for the idea - I found one here


http://www.tech-mp.com/trex_acc.php

Desc:

Use this Ferrite ring to eliminate glitches caused by your ESC. Just wrap your "ESC to Rx" lead 5 to 6 times around the ring

new one on me - will give it a spin