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All Forums >> Radios, Batteries, Clubhouse and more >> RC Radios, Transmitters, Receivers, Servos, gyros >> Re: Servo jitter
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Re: Servo jitter - 8/31/2003 8:05:11 AM   
mr_matt



Posts: 6866
Joined: 12/7/2001
From: Oak Park, CA,
Status: online 		[QUOTE]Originally posted by Thud_Driver
blkbird68

I've often wondered if that sero problem on 6V has to do with signal levels from the receiver. I haven't done the research but I think some receives are sending a "TTL like" pulse of ~3.3v to the servo which is fine on 4.8v but on 6v, maybe the servo electronics are looking more for a "CMOS like" signal needs to be significantly more than half the total volage on the system. I've never seen any of this problem on Airtonics equipment but I think they use something close to full system voltage for the servo outputs. Thoughts?? [/QUOTE]

That is exactly what happens using Futaba receivers with JR servos.

The futaba regulates the output signal ( tot he servo) down to about 3.3 volts (I think, not sure of the exact voltage). The JR servos compare the input signal to the voltage rail

So if the supply voltage is up near 6 volts, the JR servo will be comparing the 3.3 volt input signal to the supply rail. Very iffy. That is why I run 5.2V regulators.

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       Post #: 26

Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:06:04 AM   
Extra_230-RCU



Posts: 354
Joined: 9/24/2002
From: Hays, KS, USA
Status: offline 		It's a biological fact that humans cannot give birth to kittens. But the point is clearly taken.

Quite honestly, I have NO idea what you're talking about installing a external power buss. But that's okay. I'll learn.

As far as my posts being dooseys, a guy could say the EXACT same thing about you.
Clint

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       Post #: 27

Jerry - 8/31/2003 8:09:08 AM   
Thud_Driver



Posts: 1015
Joined: 12/29/2001
From: Victorville, CA,
Status: offline 		Well, if Jerry says everything is ok then I guess you're good to go.

blkbird68 - sounds like fun with electricity. Probably necessary as multiple digital rudder servo's take tons of power. I haven't gone to regulators or the like as I don't care for the extra equipment and I'm not ganging servos, but like most of the jet guys, I carry 2 Rx batteries ranging from 1600mah to 2000mah each depending on the plane.

(in reply to NeoGenesis)
       Post #: 28

Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:10:24 AM   
blkbird68


 

Posts: 639
Joined: 4/4/2002
From: Henderson, KY, USA
Status: offline 		[QUOTE]AM and FM send out different radio signals. It's just like your stereo, FM sounds better because the wavelengths are closer together and so you get a clearer sound. Same with AM and FM radios. AM's wavelengths are farer apart and thus creating the possible situations of having more glitches. Thanks. [/QUOTE]

lol...man that one has me speechless....


I guess Mr_Matt had the best reply for that one.

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       Post #: 29

Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:14:40 AM   
Extra_230-RCU



Posts: 354
Joined: 9/24/2002
From: Hays, KS, USA
Status: offline 		Okay. I'm done. I really am. I don't have to take this abuse. You guys obviously don't believe me and you sure as heck don't believe Jerry. And he has more than 130 GOOOOOD karmas on here. That has to be the most on here than anyone else. So whatever. Do what you want. I could really care less. I'm fed up with you guys. And I tell you one more thing: I don't want any of you guys posting on any of my threads and I don't want to sell any of you people anything because your true character has just come forth.
Clint

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HI Clint - 8/31/2003 8:17:15 AM   
mr_matt



Posts: 6866
Joined: 12/7/2001
From: Oak Park, CA,
Status: online 		I am just having some fun with you.

Many people post some real errors, especially here in this forum. Most people let them go, but every once in awhile people call someone on a post.

Maybe your friend Jerry has things right and you just heard wrong, who knows.

My Mom has been driving cars for 60 years, butshe could not tell you how the gas makes the car go. You can have a cursory understanding of something and really get tripped up on the details.

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Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:18:47 AM   
blkbird68


 

Posts: 639
Joined: 4/4/2002
From: Henderson, KY, USA
Status: offline 		[QUOTE]blkbird68 - sounds like fun with electricity. Probably necessary as multiple digital rudder servo's take tons of power. I haven't gone to regulators or the like as I don't care for the extra equipment and I'm not ganging servos, but like most of the jet guys, I carry 2 Rx batteries ranging from 1600mah to 2000mah each depending on the plane.[/QUOTE]

the buss is something I am doing for some friends of mine....we were playing around with some servos and measuring current draw under load...and we stumbled on the fact that at 3 amps draw the standard plugs on our equipment were showing a voltage drop of 1.75V that was across 1 plug. So anyway....i built a little buss and changed out connectors for 3 pin deans which I pulled 5 amps across one and only had .03V drop. I figured I should use it in my plane as well (don't want them thinking I built them something I wouldn't use myself). And the 7 cell pack ( I guess I could have just stuck some lithiums in there but I haven't jumped on the li-ion bandwagon yet) was to insure for my experiment that even under max load I never reached drop-out on the regs.

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Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:22:02 AM  1 votes
Extra_230-RCU



Posts: 354
Joined: 9/24/2002
From: Hays, KS, USA
Status: offline 		I just called him. He says I'm right and that I have all the facts right. However, I did not ask him about the AM and FM radio signals. That one I'm a little unsure of. But I'm pretty sure that's right. I at least know that Am came out first and Fm followed as an update. And we all know that updates are always better. Therefore, FM has fewer problems than AM, and I think HAM radios are even better yet.

But I know that I'm right about these batteries and their voltages. Thanks.
Clint

I might reconsider you guys on my threads. I haven't decided yet. I'm about ready to throw future deals with you guys (if any) in the crappper.

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Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:24:17 AM   
mr_matt



Posts: 6866
Joined: 12/7/2001
From: Oak Park, CA,
Status: online 		[QUOTE]Originally posted by Extra_230

I might reconsider you guys on my threads. I haven't decided yet. I'm about ready to throw future deals with you guys (if any) in the crappper. [/QUOTE]

I want you to know from this day forward, I am 100% commited to winning your trust back!!

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Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:24:28 AM   
blkbird68


 

Posts: 639
Joined: 4/4/2002
From: Henderson, KY, USA
Status: offline 		[QUOTE]because your true character has just come forth[/QUOTE]

excuse me???

I think you need to calm down and take a good look in the mirror.

There are many people on here that are not going to stand-by and let someone feed worthless info. to a newbie or anyone else that needs a question answered. Jerry may know what he is talking about, but I would suggest maybe taking better notes.

And you keep mentioning KARMA ratings... what does selling something to someone and actually delivering what they bought have anything to do with the credibility of your information???

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       Post #: 35

Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:24:53 AM   
Extra_230-RCU



Posts: 354
Joined: 9/24/2002
From: Hays, KS, USA
Status: offline 		So, what's the external buss thing do?
Clint

it actually sounds kinda cool.

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Oh I almost forgot - 8/31/2003 8:25:37 AM   
mr_matt



Posts: 6866
Joined: 12/7/2001
From: Oak Park, CA,
Status: online 		"Okay. I'm done. I really am. "

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Well, I can't resist this..... - 8/31/2003 8:28:42 AM   
Thud_Driver



Posts: 1015
Joined: 12/29/2001
From: Victorville, CA,
Status: offline 		Clint,

I was at McConnell AFB in in Wichita, '71/'72, before I headed off to SEA. I practiced doing nuke attack against the Hays RBS site. For us fighter guys, low level blind radar attack was still an art then, but, well, close counts in nukes and hand grenades. Looks like Hays survived, that site still there????

BTW, I flew AM in snow storms, rain storms, lighting storms, and high winds back then at the Beech model airplane park. I survived, so did the planes, but then, I was still young and foolish.

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Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:29:20 AM   
blkbird68


 

Posts: 639
Joined: 4/4/2002
From: Henderson, KY, USA
Status: offline 		[QUOTE]But I know that I'm right about these batteries and their voltages. Thanks. [/QUOTE]

you are right that all cells reach a point during discharge at which the cell voltage drops rapidly under load...you have however misinterpreted the information you have been given.


[QUOTE] Therefore, FM has fewer problems than AM, and I think HAM radios are even better yet.
[/QUOTE]

the only ham equipment I have is AM so I guess that puts a kink in you r theory.

(in reply to NeoGenesis)
       Post #: 39

Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:30:42 AM   
Extra_230-RCU



Posts: 354
Joined: 9/24/2002
From: Hays, KS, USA
Status: offline 		Just ask Jerry. He's got more experience than all of us that has posted on here so far. Then quote back what he says. If you do, I KNOW you guys will owe me an apology. It'll be good practice for ya. Go ahead and ask him.
Clint

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Airtronics at 6.0 Volt? Ok or not? - 8/31/2003 8:31:37 AM