SEVERE RADIO Glitching problem, Any ideas??

[jcboof]

Hey guys, I've just finished building a sportsman rig for my wife to use and I had it set up with my Futaba 3PK operating on the FASST system. I decided to get a cheap radio so she could have her own. I got a JR XR2I 2channel 75mhz AM radio and receiver from another member here on RCC. I only paid 20 bucks for it so I figured it was a good deal. Simple radio, Simple price.

Now. The crawler operated perfectly fine on the Futaba radio, When I hooked things up today with the JR radio, the crawler started twitching and glitching like CRAZY!!!!!!!!! This seems to be a RANGE sensitive problem too. When the mast on the radio is down, even standing 1 foot away from the crawler, it glitches and twitches around like crazy. When I extend the mast, everything is fine. I can drive the crawler around about 2-3 feet away from me and then it starts to glitch and twitch again. I've remounted the receiver away from my esc and routed the antenna wire through an antenna straw up about 1 ft and it still glitches. I can get a max of 4-5 feet away from the crawler then it starts to glitch!

Any ideas?? Bad radio?? bad receiver?? Interference??? POS???

[Jkelley]

Well I would hope it isnt the radio or receiver because I've trusted Jr for a while now with my Radio's. But you never know what kind of things the other person put it through. I would maybe consider trying a new crystal in the radio and reciever maybe. Just an idea. Have you tried swapping crystals. I dont think it matters on AM radios but hey thats what trouble shooting is about, eliminating possiblities.

[Jkelley]

I do know on am radio the antenna length DOES matter. Does it show any signs up being maybe cut off shorter or anything.

[jcboof]

I have 3 other sets of crystals I've tried, No difference. The antenna seems the correct length, The insulator on the antenna wire is cut in a few places, bare wire showing, I've heat shrinked the exposed wires, and no difference.

[squatch71]

yeah, mine has to be up all the way even if I'm 5 feet away. I like the JR radios...seem to work well for being "cheap"

[Jkelley]

I would guess either the rx or the tx is bad then. I dont know how you would figure out which one with out either a spare receiver or spare radio. I've never delt specifically with JR am radios I've only had FM or spektrum radios. Sounds to me like something isnt right with one or the other.


Have you maybe taken the radio or receiver apart to see if maybe a wire maybe pulled out of the board. Just a thought.

[jcboof]

Kinda what i'm thinking, Maybe the RX is the culprit. I remember back in the day when I'd run my REVO through the mud and I'd wash it off afterwards, Getting some water in the receiver box would cause it to act almost the same, Glitching like crazy and not working right. After I dried things off, it was all ok!

I pulled the rx apart and noticed some corrosion on the board, apparently was wet at one time, I cleaned the board up with some electrical cleaner and no change yet. I just wish I had a spare RX to try.

[BLKXJ 96]

I have a Futaba Magnum (old 75mhz) radio and it would do the same thing you are talking about. If I mounted the RX on end (standing up) the radio would work fine.

[Reflection]

Something to try,might be a slim chance.

I've seen trim adjustments do weird things,glitches being one of them.

Are the trim settings on the new radio set at zero when you hooked it all up?

[jcboof]

huh, weird, I'll give that a try!

[jcboof]

Originally Posted by Reflection

Something to try,might be a slim chance.

I've seen trim adjustments do weird things,glitches being one of them.

Are the trim settings on the new radio set at zero when you hooked it all up?

Seeing that this seems to be more of a "RANGE" problem, I'm not sure that it would cause that problem. The settings were all at 0 before I hooked everything up.

It works perfectly fine if I am within 2 feet or so of the receiver, but once I try to drive the truck away from me, it starts to glitch once its about 4-5 feet away.

[Reflection]

Originally Posted by jcboof

Seeing that this seems to be more of a "RANGE" problem, I'm not sure that it would cause that problem. The settings were all at 0 before I hooked everything up.

It works perfectly fine if I am within 2 feet or so of the receiver, but once I try to drive the truck away from me, it starts to glitch once its about 4-5 feet away.

Just an idea.

It's a good habit to get into to double check trims and set them at zero before hooking stuff up. Not doing that in the past,has caused me allot of weird issues.

[jcboof]

Cool, Thanks for the ideas though! Much appreciated, I'm likely going to reset the radio again, then remount the receiver and try it again!

[indiana mudcat]

i had the same issue's until i went 2.4, tried everything under the sun, i could minimize it but never could stop it. what ESC are you using, i've saw alot of people on here try to run a goat on AM (myself also) have this issue and i've heard FXR's don't like AM either. IMO there's just to much metal on these for AM.

[rmdesignworks]

what kind of servo are you running,,digital or analog?,,

do you have a spare out of car servo,,if so remove the rX from the rig and power it with batteries seperate,,plug in the spare servo and see if it still does it,,you may be getting a cross interferrence form the other electronics in the rig,,too much interferrence for the rx to handle and filter,,it dosnt sound like bad equipment but a neew set of crystlas might help but i think youll find it work if it isnt hooked up to everything else