I'm having a problem with the subject receiver and I wanted to hear
some opinions. I'm using the above receiver with my JR radio and on a
parkflyer. First of all the servos (all GWS brand) jitter when I turn
on the Radio with the antenna collapsed & the radio next to the plane.
This goes away when I extend the antenna. However, when I start flying
I get sporadic servo jitters and this has happened when the plane has
been as far as 50 feet away at two different fields. Is this a common
problem or is my receiver bad? For whatever difference this may make, I
have used my JR radio with full size JR brand FM and PCM receivers and
I have never had any problems. Thanks in advance,
Matt
I have two different electrics I fly with GWS Receivers, one 4-channel Pico
and 1 6-channel Naro. The Pico flies with GWS Pico servos while the Naro
flies with Hitec HS-55s. I fly both with my Futaba 7C transmitter and I've
never suffered from radio interference with either setup. I fly both
indoors and outdoors with both planes.
Is it possible that you have a negative shift GWS receiver and that's why
it's not working well with your positive shift JR transmitter? GWS does
make two different versions of each receiver - one for JR/Airtronic and one
for Futaba/Hitec. If that isn't the problem, you probably just have a bad
receiver.
I haven't heard too many folks praise GWS receivers, but my experiences over
many months of flying have all been good.
I had a similar problem which narrowed down to a loose fit of the crystal
pins in the crystal holder. I solved it by soldering the crystal in place.
Range is good for as far away as I fly the fomie.
What ESC are you using, how many servo's and what battery are you using.
Dad was having a similar problem due to using a 3s (11.1v) lipo and 4
(micro) servos and he would get jitters after 20ft, all due to exceeding the
servo count for his ESC/Battery voltage combo.
Either get a better ESC or a seperate UBEC.
Cheers.
Gerrit.
| Is it possible that you have a negative shift GWS receiver and
| that's why it's not working well with your positive shift JR
| transmitter?
Unlikely. If that were the case, it wouldn't work at all.
| If that isn't the problem, you probably just have a bad receiver.
Could be. Could also be that the fields in question just have too
much RF noise and they'll need a better quality receiver.
| I haven't heard too many folks praise GWS receivers
They're very inexpensive.
They're small.
They're better than the Hitec Feather.
That's praise, sort of :)
But there's some bad things too --
They are not good at rejecting interference.
They have very limited range (which was probably done deliberately
in order to reduce the amount of interfence they pick up.)
| > First of all the servos (all GWS brand)
The servos or their brands are unlikely to be a factor.
| > jitter when I turn on the Radio with the antenna collapsed & the
| > radio next to the plane. This goes away when I extend the
| > antenna. However, when I start flying I get sporadic servo jitters
| > and this has happened when the plane has been as far as 50 feet
| > away at two different fields. Is this a common problem or is my
| > receiver bad?
The cheap single-conversion receivers don't reject interference well.
There are good single conversion receivers, like those by JR and Berg,
but the GWS receivers do not fit into this category.
It could be that your RX is defective, or it could be that it's
picking up some noise from somewhere and so you'd need a better RX.
It's also possible that the noise is so strong and so close that even
a better RX won't fix the problem, but that's not really likely.
| > For whatever difference this may make, I have used my JR radio
| > with full size JR brand FM and PCM receivers and I have never had
| > any problems.
PCM RX's should never glitch under any conditions. You still lose
control under the same conditions, but when you do, the servos either
stay still or go to the failsafe position. But they should not glitch.
Of course, this also means that a range test with a PCM RX where
you're looking for glitches is useless. Instead, you need to look for
the servos moving to failsafe positions, or make sure they keep moving
(if you can have somebody wiggle the sticks for you, or you can wiggle
the sticks as you walk with the TX away from the plane.)
Are you saying two pilots can fly at the same field on the same channel so
long as one is flying JR/Airtronic and the other is flying Futaba/Hitec?
"Doug McLaren" wrote in message
I do not get any jitters while I'm next to my planes with the antenna
collapsed. My radio system exhibits no interference with either of my GWS
receivers.
I am using a 10A Brushed ESC by Green Models with the two HS55 servos on my
Colorful Butterfly. It came with a 650ma 8-cell NiCad pack. I am using an
Electrifly C-12 Brushed ESC with the three GWS Pico servos on my Thunder
Tiger Christen Eagle EP Profile. I use 3S 640ma Electrify LiPo packs with
the TT Christen Eagle.
| Are you saying two pilots can fly at the same field on the same channel so
| long as one is flying JR/Airtronic and the other is flying Futaba/Hitec?
No. I'm saying that using a negative shift TX with a positive shift
RX or vice versa generally doesn't work at all -- either the servos
just sit there unmoving, or glitch like mad. It usually won't
manifest as working only at short range, or just glitching a little
bit -- it's typically an all or nothing thing.
Two pilots can't use the same channel in the same place, not even if
they have different shifts, or AM vs FM, or PPM vs PCM, and not even
with the new fangled DSP receivers that `lock' onto your signal and
will only respond to your TX.
(In that last case, it may not respond to the other TX, but unless it
can pick up your TX's signal, it's not going to work properly.)
Spread spectrum, take us away!
| "Doug McLaren" wrote in message
| > | Is it possible that you have a negative shift GWS receiver and
| > | that's why it's not working well with your positive shift JR
| > | transmitter?
| >
| > Unlikely. If that were the case, it wouldn't work at all.
Thanks for everyone that has responded.
I'm using the said receiver with four GWS servos and a Hacker X20 ESC
and a Hacker A20-20L motor. I will play with the crystall to see
whether that is the culprit.
Matt
Thanks for the clarification, Doug. I've never seen what happens when you
try using a negative shift receiver with a positive shift transmitter or
visa versa. I was curious what the effect would actually be. ahdofu's
original discription sounded like it might be attributable to such a
mismatch, but you seem confident such a mismatch would result in more severe
symptoms.
I had a similar problem that turned out to be my motor (different receiver,
though). I put new capacitors on it, but that didn't help. Replacing it
solved the problem. The motor had been crashed once.
My 4 channel GWS receiver will glitch with the Tx off, but is fine with the
Tx on.
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