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<DIV><FONT face=Arial size=2>OK, I set up an attenuator on the signal to get
results on a handful of servos. Jim O. already did this, but I think it
was with just one servo? I don't have his post anymore.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>This test was done with a 10K Bournes precision
pot, ground to one lead, signal out to servo the wiper, signal in from the
receiver to the other end. Aileron channel on the R921 used for signal
attenuation tests, rudder used to add a separate DS8611 servo load to induce
crosstalk. Added lead length of attenuator network about 1 foot of
extension wiring. Signal level measured about midway in the 1 foot of added
wiring. This would be rouighly equivilent to what's happening halfway
along an aileron extension in a Pattern bird. Also, I tried a couple of
old analog Futaba servos I had.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Results:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>DS8411A</FONT></DIV>
<DIV><FONT face=Arial size=2>Loads the test network by about 0.05V
drop</FONT></DIV>
<DIV><FONT face=Arial size=2>Below 1.2V, totally uncontrolled response or no
response.</FONT></DIV>
<DIV><FONT face=Arial size=2>1.2V - Very jumpy, not really controllable, even
when the 8611 was silent or disconnected. Significant crosstalk from 8611
when active. The lightest touch on the 8611 to try to move it would set
off the 8411 on the test channel. You would crash.</FONT></DIV>
<DIV><FONT face=Arial size=2>1.3V - Jittery, but controllable. Noticeable,
but improved crosstalk from 8611. You might make it in, but your shorts
may need laundering.</FONT></DIV>
<DIV><FONT face=Arial size=2>1.4V - Solid.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>DS9411A</FONT></DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>Loads the test network by about 0.05V
drop</FONT></DIV></FONT></DIV>
<DIV>0.1V better than the 8411, otherwise a carbon copy of it's performance,
just offset by +0.1V. The small difference is likely explained by
component tolerances and less noise injected on the power rails because the 9411
is a lower torque servo.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>DS8611</FONT></DIV>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>Loads the test network by about 0.05V
drop</FONT></DIV></FONT></DIV>
<DIV>0.1V worse than the 8411. It's a much higher torque servo and injects about
0.2V of noise on the ground lead every time the motor moves. The 8411
injects a little less noise, something like 0.5V less, but I can't measure
that accurately.</FONT></DIV></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>DS821</FONT></DIV>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>Loads the test network by about 0.2V
drop</FONT></DIV></FONT></DIV>0.85V - No response</FONT></DIV>
<DIV><FONT face=Arial size=2>0.9V - wild response (see 8411 notes above
about crashing at 1.2V)</FONT></DIV>
<DIV><FONT face=Arial size=2>0.95 - Just barely controllable, a lot of
crosstalk. You would still crash, but it might take a little
longer.</FONT></DIV>
<DIV><FONT face=Arial size=2>1.0V - A little jumpy, some crosstalk.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>NES-4131</FONT></DIV>
<DIV>Loads the test network by about 0.1V drop</DIV>
<DIV><FONT face=Arial size=2>1.3V - Very wild response, frequently drives to the
stops</FONT></DIV>
<DIV><FONT face=Arial size=2>1.35V - Slightly jittery, some
crosstalk</FONT></DIV>
<DIV><FONT face=Arial size=2>1.4V - Fairly solid, milder crosstalk</FONT></DIV>
<DIV><FONT face=Arial size=2>1.5V - Solid, very mild crosstalk</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Futaba S3101</FONT></DIV>
<DIV><FONT face=Arial size=2>Requires 1.5V to work solid</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Futaba S9602</FONT></DIV>
<DIV><FONT face=Arial size=2>Works well at 1.1V</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I also tried adding a 2nd DS series servo to the
test channel (added a 9411 to an 8411) while the 8411 was set to work at 1.3V
(controllable, but jittery). I deliberately did not adjust the signal
level to compensate for the additional load and observed that it became very
wild for both servos. This is to be expected, since the signal level was
already a what I would consider the minimum controllable level. The 9411 added
load knocked it down roughly another 0.5V, but also added more noise to the
equation.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>So to summarize, when you get out at longer lead
lengths, the effects of signal degration to to crosstalk, capacitive loading etc
becomes worse than in my test. In a pattern plane, not so bad, but in a
big IMAC thing, watch out. Double up on servos on an extension, worse
again. Add higher torque servos, worse again. These are intended as useful
guidelines and not absolutes. I still think the margins are uncomfortably
low with only a 2.7V receiver output, but maybe Futaba or JR has a different
view.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Ed</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=ed_alt@hotmail.com href="mailto:ed_alt@hotmail.com">Ed Alt</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">General pattern discussion</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, November 22, 2008 9:00
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Futaba
R6014FS Receivers</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>I don't know what their limit is, but I did just
scope the output of a Spektrum R921 and it's a 3.4V pulse on an unloaded
channel. A lot of this can depend on lead length and drive capability of
the channel output, so 3.4V from a R921 or 2.7V from a R6014S becomes
something less at the servo input. I still have an R955, but I can't
measure it since I no longer have a PCM Tx (it's for sale too -
cheap!).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Ed</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=jpavlick@idseng.com href="mailto:jpavlick@idseng.com">John
Pavlick</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">General pattern
discussion</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, November 22, 2008 1:36
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Futaba
R6014FS Receivers</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Ed,</FONT></DIV>
<DIV><FONT face=Arial size=2> What do the typical JR servos that we use
in Pattern planes (8411, 9411, etc.) like to see? I want to use them with my
Futaba 5114 (PCM - G3, 72 Mhz) receivers. I'll check the signal levels on
the receivers this weekend.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>John Pavlick<BR><A
href="http://www.idseng.com">http://www.idseng.com</A></FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=ed_alt@hotmail.com href="mailto:ed_alt@hotmail.com">Ed Alt</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=bob@toprudder.com
href="mailto:bob@toprudder.com">bob@toprudder.com</A> ; <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">General pattern
discussion</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, November 22, 2008
12:00 AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion]
Futaba R6014FS Receivers</DIV>
<DIV><BR></DIV>
<DIV>Aside from using a purpose built servo that matches logic families
with the receiver, the only real solution is to insert a level translater
in between; basically a simple buffer that allows you to take a lower
voltage ourput signal from one logic family in the receiver and boost the
signal level to work with a servo that requires higher levels for safe
operating margins. Personally, I would not fly other servos without
doing this, even if they seem to be working fine. Jim Oddino's
post used two very instructive words: "ragged
edge". </DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Ed</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=bob@toprudder.com href="mailto:bob@toprudder.com">Bob
Richards</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">General pattern
discussion</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, November 21, 2008
9:42 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion]
Futaba R6014FS Receivers</DIV>
<DIV><BR></DIV>
<TABLE cellSpacing=0 cellPadding=0 border=0>
<TBODY>
<TR>
<TD vAlign=top>
<DIV>I think I read somewhere that the R608FS receiver uses the
same chipset and has the same problem.</DIV>
<DIV> </DIV>
<DIV>So far I have not had any problems with the servos that I
use, but I was not able to check the pulse width out
of the higher channels with my Hitec programmer. I have to
wonder, however, exactly what is the logic level for the various
servos? Also, does the logic level of the servo change with a
different battery voltage? Does the output level from the rx
change with a different battery voltage?</DIV>
<DIV> </DIV>
<DIV>I guess this is a good reason to use some sort of output
conditioner (powerbox, etc) if mixing brands of receivers and
servos.<BR></DIV>
<DIV>Bob R.</DIV>
<DIV> </DIV>
<DIV><BR>--- On <B>Fri, 11/21/08, MKMSG
<I><mkmsg@cox.net></I></B> wrote:<BR></DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: rgb(16,16,255) 2px solid">From:
MKMSG <mkmsg@cox.net><BR>Subject: [NSRCA-discussion]
Futaba R6014FS Receivers<BR>To: "NSRCA Discussion List"
<nsrca-discussion@lists.nsrca.org><BR>Date: Friday,
November 21, 2008, 1:15 AM<BR><BR>
<DIV id=yiv1661051185>
<STYLE></STYLE>
<DIV><FONT face=Arial size=2>I was reading the FAQ section of
the Futaba website when a particular item caught my eye
regarding the R6014FS 2.4 receiver. The FAQ states that
<FONT face="Times New Roman" size=3>the use of non Futaba
digital servos with the R6014FS receiver may be problematic due
to the 6014's lower output voltage of 2.7 volts. Since I
do occasionally mix and match Futaba and JR servos and use the 8
channel 2.4 receiver, I wondered if this issue was common to all
Futaba 2.4 receivers. Here's Futaba's answer: "The FAQ
refers only to the R6014FS receiver, this is the only one that
has the lower voltage." Just thought I'd pass this along
in case someone experiences performance anomalies with the 6014
receivers using other than Futaba servos.</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2><FONT face="Times New Roman"
size=3></FONT></FONT> </DIV>
<DIV><FONT face=Arial size=2><FONT face="Times New Roman"
size=3><FONT face=Arial size=2>Mike</FONT></FONT></FONT></DIV>
<DIV><FONT face=Arial size=2><FONT face="Times New Roman"
size=3><FONT face=Arial size=2>NSRCA 35</FONT></DIV>
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