RC Radios, Transmitters, Receivers, Servos, gyros Discussion all about rc radios, transmitters, receivers, servos, etc.

Servo extension wire?

Reply

Old 12-13-2004, 05:43 PM
  #1  
BBW Walt
Thread Starter
My Feedback: (11)
 
BBW Walt's Avatar
 
Join Date: Jan 2002
Location: NWest, IN
Posts: 962
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Servo extension wire?

I have been making my own extensions for myself and others for quite a while. I have used both braded and ribbon wire for all types of applications with no issues. Popular belief is that braded or twisted wire is less prone for interference and RF issues. Is there any information available to support this wifes tale or is that all it is. I would appreciate any of the electrical guru's chiming in on this issue..Thanks in advance Walt
Attached Thumbnails Click image for larger version

Name:	Wu60153.jpg
Views:	16
Size:	50.1 KB
ID:	202528  
BBW Walt is offline  
Reply With Quote
Old 12-13-2004, 11:43 PM
  #2  
dirtybird
My Feedback: (5)
 
Join Date: Jan 2002
Location: San Tan Valley, AZ
Posts: 5,768
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Twisting is used primarily by the telephone industry to reduce crosstalk between wires that run for miles in close contact. It is also used to minimise noise pick up in low level instrumentation cable. For low level instrumentation, it is used with balanced differential inputs to the amplifier. It has little benifit for the R/C operation.
If you have several high torque digital servos to drive and the wires to them are close together it might help to prevent cross coupling.
It is no help to prevent RF interference.
dirtybird is offline  
Reply With Quote
Old 12-14-2004, 02:02 PM
  #3  
Rodney
Senior Member
 
Join Date: Dec 2001
Location: FL
Posts: 7,769
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Dirtybird beat me to it and has pretty well said it all.
Rodney is offline  
Reply With Quote
Old 12-15-2004, 06:24 AM
  #4  
BBW Walt
Thread Starter
My Feedback: (11)
 
BBW Walt's Avatar
 
Join Date: Jan 2002
Location: NWest, IN
Posts: 962
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Thanks dirtybird...
BBW Walt is offline  
Reply With Quote
Old 12-15-2004, 05:21 PM
  #5  
Lynx
Senior Member
 
Join Date: Sep 2002
Location: Rochester, NY
Posts: 1,373
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Twisted wire has a downfall as well, that being that given identical wire sizes twisted wire is going to have a slightly higher resistance than straight wire due to the twists causing more wire to be used for actual inch of length.
Lynx is offline  
Reply With Quote
Old 12-15-2004, 08:18 PM
  #6  
JNorton
My Feedback: (2)
 
JNorton's Avatar
 
Join Date: Jan 2002
Location: Coopersville, MI
Posts: 4,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Good grief Lynx,
#24 guage has 27.3 ohms per 1000 foot = .0273 per foot so even if you are talking about a 24" extension actually having 36" of wire you are only talking about an extra .0273 ohms of resistance.

John

Actually a pretty good case to use #22 guage for twisted cables if your going to worry about it.
JNorton is offline  
Reply With Quote
Old 12-16-2004, 10:20 AM
  #7  
mglavin
My Feedback: (31)
 
Join Date: Nov 2001
Location: Elverta, CA
Posts: 5,295
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Info garnered from a respected RC modeler and Aerospace EE below:

As usual there are several points of view on the validity and or application of various techniques used to rig our models, below is another.

The main reasons OEM's do not use, let alone suggest twisted lead, is cost. The whole process of manufacturing anything made out of ribbon based electrical wire is cost. The whole process is automated, including the testing (if they are actually tested that is). Alas the suggestion (by an OEM) that twisted leads may enhance product performance leaves them open to litigation (this is a no-brainer).

Fact is, oodles and oodles of pilots are using none other than OEM-style (ribbon) cabling, and their systems are not (at least visually)exhibiting lack of control integrity as they merrily pirouette through blue yonder. The point is, as it always should be, is to apply those things that will increase RF operational headroom IN THE EVENT that it might come in handy! It may be the difference between landing your bird safely after that ignition GND strap is no longer grounded (but still creating one helluva spark), or looking for a trash bag.

Another fact. Control or signal integrity, better yet immunity to extraneous EMI/RFI is enhanced by allowing conductors to see that same extraneous noise equally. I have seen it, measured it, and applied it not only to our hobby/sport but on projects within the electronics industry. This is not rocket science.

Technically what occurs is that all the conductors are subject to energy that is associated with EMI/RFI. Because there are 2 vectors (90 degrees opposed) within EMI/RFI, or any electro-magnetic wave for that matter, twisting physically associates all 3 conductors to the same level of energy in both vectors, allowing energy to rise and fall equally. One or more twists per inch is adequate @ 72MHz.

What motivates me to respond are those who ignore the evidence, and wish to increase their own level of security by publicly stating that their systems have worked for years, THEREFORE, there can not be a problem. I think everybody should be given a pulse emission detector to just see how many times while you are painting the sky, your communications link fails...and you don't even know it let alone see it. It would probably cause a lot of you to re-think just how you fly.

Sorry everyone for getting antsy...but we are talking about relatively inexpensive 0.60-sized run-of-the-mill aircraft, but big, mean, and RF-noisy aerobats that cost big cabbage. It is simple things like this that everyone can do to enhance safety, not to mention the longevity of one your pride-and-joys.
mglavin is offline  
Reply With Quote
Old 12-16-2004, 12:20 PM
  #8  
JPMacG
My Feedback: (2)
 
Join Date: Jan 2002
Location: Ivyland, PA
Posts: 2,277
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Here is yet another opinion. I say this a professional engineer involved with antennas, transmission lines, and EMI/EMC.

Twisting has only a very slight advantage, if any, over flat ribbon. The advantage is in situations where the conductor pairs are in close proximity to other cables or metallic objects and coupling is capacitive or inductive. Twisting has no advantage over flat cable with regard to EM radiation from the cable, or pickup from a radiated EM field.

This may not be rocket science but it certainly not simple or obvious. Just making meaningful measurements is a real art. It is very easy to draw false conclusions.
JPMacG is offline  
Reply With Quote
Old 12-16-2004, 12:35 PM
  #9  
dirtybird
My Feedback: (5)
 
Join Date: Jan 2002
Location: San Tan Valley, AZ
Posts: 5,768
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

ORIGINAL: mglavin

As usual there are several points of view on the validity and or application of various techniques used to rig our models, below is another.

The main reasons OEM's do not use, let alone suggest twisted lead, is cost. The whole process of manufacturing anything made out of ribbon based electrical wire is cost. The whole process is automated, including the testing (if they are actually tested that is). Alas the suggestion (by an OEM) that twisted leads may enhance product performance leaves them open to litigation (this is a no-brainer).

Fact is, oodles and oodles of pilots are using none other than OEM-style (ribbon) cabling, and their systems are not (at least visually)exhibiting lack of control integrity as they merrily pirouette through blue yonder. The point is, as it always should be, is to apply those things that will increase RF operational headroom IN THE EVENT that it might come in handy! It may be the difference between landing your bird safely after that ignition GND strap is no longer grounded (but still creating one helluva spark), or looking for a trash bag.

Another fact. Control or signal integrity, better yet immunity to extraneous EMI/RFI is enhanced by allowing conductors to see that same extraneous noise equally. I have seen it, measured it, and applied it not only to our hobby/sport but on projects within the electronics industry. This is not rocket science.

Technically what occurs is that all the conductors are subject to energy that is associated with EMI/RFI. Because there are 2 vectors (90 degrees opposed) within EMI/RFI, or any electro-magnetic wave for that matter, twisting physically associates all 3 conductors to the same level of energy in both vectors, allowing energy to rise and fall equally. One or more twists per inch is adequate @ 72MHz.

What motivates me to respond are those who ignore the evidence, and wish to increase their own level of security by publicly stating that their systems have worked for years, THEREFORE, there can not be a problem. I think everybody should be given a pulse emission detector to just see how many times while you are painting the sky, your communications link fails...and you don't even know it let alone see it. It would probably cause a lot of you to re-think just how you fly.

Sorry everyone for getting antsy...but we are talking about relatively inexpensive 0.60-sized run-of-the-mill aircraft, but big, mean, and RF-noisy aerobats that cost big cabbage. It is simple things like this that everyone can do to enhance safety, not to mention the longevity of one your pride-and-joys.
Tell me - if two vectors are at 90 degrees how can they be opposed?
Twisting can help eliminate EMI(Electro magnetic induction) if the wires are running in parallel. But not if you twist all the cables the same.
Twisting can also help eliminate RFI(radio frequency interference) or noise on the line if we use balanced differential inputs to our amplifiers. The trouble is our inputs are single ended. An easier way is just to use bypass capacitors. Whch I am sure our receivers do.
If twisting makes you feel better go ahead and do it. It can't hurt. As someone else pointed out there is little increase in the resistance of the line.
dirtybird is offline  
Reply With Quote
Old 12-16-2004, 06:02 PM
  #10  
Lynx
Senior Member
 
Join Date: Sep 2002
Location: Rochester, NY
Posts: 1,373
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Norton, I think you overestimate the proper current carrying capacity of a given size of wire, just because the wire's big enough to carry the power and not overheat doesn't mean you should be using it.
Here's a few examples.

At 4.8volts, under a 300ma load (sounds about what a servo draws under worst case scenario)

AWG---Volts at load---Ma's wasted heating the wire
28---4.742---84
24---4.779---30
20---4.791---12
18---4.794---8

Keep in mind, power dissipated by the wire itself (considering it's length) can be harmonically magnified at the servo refresh rate of about 50hz due to the very low capacitance of a wire of that length you can be talking relativly large amounts of harmonic interaction across the length of the wire. Since it happens to be around the edge of the length of a 1/4 wavelength whip on the 72mhz spectrum that 'little bit' of resistance can cause some relativly strong feedback to form, both as distortions in the servo signal and possible short (virtually non detectable) spikes of EMF on the 72mhz spectrum. Every single last nano ohm counts to reducing possibilities of inductive reactance.
Lynx is offline  
Reply With Quote
Old 12-16-2004, 09:42 PM
  #11  
dirtybird
My Feedback: (5)
 
Join Date: Jan 2002
Location: San Tan Valley, AZ
Posts: 5,768
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

ORIGINAL: Lynx


Keep in mind, power dissipated by the wire itself (considering it's length) can be harmonically magnified at the servo refresh rate of about 50hz due to the very low capacitance of a wire of that length you can be talking relativly large amounts of harmonic interaction across the length of the wire. Since it happens to be around the edge of the length of a 1/4 wavelength whip on the 72mhz spectrum that 'little bit' of resistance can cause some relativly strong feedback to form, both as distortions in the servo signal and possible short (virtually non detectable) spikes of EMF on the 72mhz spectrum. Every single last nano ohm counts to reducing possibilities of inductive reactance.
This sure does not make any sense to me.
dirtybird is offline  
Reply With Quote
Old 12-16-2004, 10:21 PM
  #12  
lex2bits
Senior Member
My Feedback: (12)
 
lex2bits's Avatar
 
Join Date: Apr 2004
Location: ALBUQUERQUE, NM
Posts: 229
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Michael,

The Hitec servos (475HB's & 5645MG's) I bought recently have twisted leads that I need to extend. Can you tell me the ga. it is, how many strands and where I can get some?

Ray
lex2bits is offline  
Reply With Quote
Old 12-16-2004, 11:20 PM
  #13  
mglavin
My Feedback: (31)
 
Join Date: Nov 2001
Location: Elverta, CA
Posts: 5,295
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

DB, et all

Find below a response from the author I referenced above as "another view "


"90 degrees opposed" refers to the fact that both the electric and magnetic fields (in the form of sine waves) are in synch, but their peak energy force is opposed. This is what sustains it. A quick search through this illustration:

http://imagers.gsfc.nasa.gov/ems/waves2.html

As they occupy different planes, their energy is not seen simultaneously by leads located in the same plane (parallel for example).

Twisting all the leads "the same" (I will assume the same way - or direction) is irrelevant, you could twist in either direction, or braid. The net result is all leads are subject to the same increase or decrease in extraneous energy in such a configuration. This is fundamental physics of energy transfer.

All leads that are (adequately) twisted (1 revolution/2 inch minimum @ 72MHz) will see similar gains and losses in extraneous EMI/RFI (technically - at any given angle of energy transfer, there are only points where one could say they are actually the same). Obviously, similar is better than dissimilar.

All 3 leads benefit from this, not just the signal lead. In fact there can be enough EMI present from ignition systems to play havoc with DC at the RX itself. Also, one should not lose sight of the fact it is a square wave being sent to the servo to define pulse width. Start thinking about square waves, and their associated harmonics, now look at energy gain/loss from extraneous noise, too much to get into here.

Extraneous noise, no matter what form it takes, is seen equally by ALL the leads when ALL leads are physically exposed to that energy. Same principle applied to single source and differential inputs on data acquisition systems. Single-ended inputs are sensitive to noise errors. Noise (unwanted signal contamination) is added because signal wires act as aerials, picking up environmental electrical activity (eg: ignition sys). More importantly as the GND is common throughout, a change in energy seen by it OR the signal lead independently can exacerbate the issue (that being a reaction to a change in voltage/current which adversely effects RX operation, servo operation, or signal reception).

Capacitors are present but not that effective, which ignitions systems could care less, as the broadband energy (EMI/RFI - DC to GHz) is destructive on not just the signal lead, but all electrical aspects of the RX system. Reducing changes in energy as seen by individual leads (not wire or cable, but individual leads) reduces errors.

"It can't hurt" is true. Does it offer a performance gain, yes.

It has been measured and observed in countless situations I have solved for pilots, on paid projects during design and verification (board level changes right up through cable configuration changes etc on many projects), on RPV-based multiple communications protocol issues, electromagnetic bearing control, GPS/DGPS communications (specifically ignition and communications EMI/RFI on spray aircraft), I could go on
and on.

The bottom line is a measurable increase in headroom, which everyone can use these days. The justification for not doing it would be those who claim to not have a problem. To those I will rent an onboard pulse emission detector to record just how many times in any given flight they were not communicating with their aircraft. Then they can go and perform simple changes and see the results for themselves...
mglavin is offline  
Reply With Quote
Old 12-16-2004, 11:25 PM
  #14  
mglavin
My Feedback: (31)
 
Join Date: Nov 2001
Location: Elverta, CA
Posts: 5,295
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

lex

Custom Electonics offers twisted wire and I am sure others do as well. Hitec is going to offer HD twisted extensions in the future as well as the twisted wire in bulk in the future I am told.

The twisted wire on Hitec servos is 22awg as far as I know.
mglavin is offline  
Reply With Quote
Old 12-17-2004, 12:22 AM
  #15  
lex2bits
Senior Member
My Feedback: (12)
 
lex2bits's Avatar
 
Join Date: Apr 2004
Location: ALBUQUERQUE, NM
Posts: 229
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Thanks Michael,

I prefer soldered splices over plug-in extensions, so I'll try Custom Electronics for bulk wire.

Do you have a URL for them?.... all I get on google is music vendors.

I found Hitec flat ribbon 22ga in bulk @ Servo City, but no twisted wire.

Ray
lex2bits is offline  
Reply With Quote
Old 12-17-2004, 01:58 AM
  #16  
mglavin
My Feedback: (31)
 
Join Date: Nov 2001
Location: Elverta, CA
Posts: 5,295
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Ray

Try below. Hitec has the twisted extension slisted in their catalog, apparently not on the website. The twisted wire is down the road.

http://www.siriuselectronics.com/ind...4e18e6b81e4137

http://radicalrc.secure-mall.com/sho...64&cart=258561
mglavin is offline  
Reply With Quote
Old 12-17-2004, 02:36 AM
  #17  
Lynx
Senior Member
 
Join Date: Sep 2002
Location: Rochester, NY
Posts: 1,373
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

mglavin, I would be interested to see the difference in performance of twisted wire vs straight wire on paper. Make two sets of leads, twisted and straight. Put them on the same plane and then using your glitch counter show us on paper through a standardized set of test movements and positions where the advantage is.
Lynx is offline  
Reply With Quote
Old 12-17-2004, 07:41 AM
  #18  
JNorton
My Feedback: (2)
 
JNorton's Avatar
 
Join Date: Jan 2002
Location: Coopersville, MI
Posts: 4,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Lynx,
At 4.8volts, under a 300ma load (sounds about what a servo draws under worst case scenario)

AWG---Volts at load---Ma's wasted heating the wire
28---4.742---84
24---4.779---30
You've stated using a 4.8 volt source with a 300 mA load. The voltage measure across the load using 24 gauge wire is 4.779 volts. The wire is in series with the load. Therefore according to Kirchoff's law 300 mA flows from the battery thru the wire and the load returning to the battery. You cannot have 30 mA wasted heating the wire. The wire voltage loss is 4.8 - 4.779 or .021 volts. 300 mA is flowing thru the wire. Wattage is voltage times current so .021 * .3 is .0063 watts. This is the amount of power dissipated. Total power is 4.8 * .3 = 1.44 watt. Power delivered is 1.4337 watt. Efficiency is (1.44/1.4337)*100 = 99.5625 percent. Using 24 gauge wire in your example therefore has an inefficiency of .4375 or less than 1/2 percent.

Since it happens to be around the edge of the length of a 1/4 wavelength whip on the 72mhz spectrum that 'little bit' of resistance can cause some relativly strong feedback to form, both as distortions in the servo signal and possible short (virtually non detectable) spikes of EMF on the 72mhz spectrum.
ΒΌ wave is 39 inches. My servo connections are usually 24, 12 or 6 inch which are not a harmonic mutilple. If and when I get to giant size planes I'll use a ferrite bead to decouple any harmonic generated EMF.

John
JNorton is offline  
Reply With Quote
Old 12-17-2004, 10:57 AM
  #19  
JPMacG
My Feedback: (2)
 
Join Date: Jan 2002
Location: Ivyland, PA
Posts: 2,277
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

I'm sorry MGlavin, but in my opinion you are providing incorrect information. Twisting will not prevent a parallel transmission line from radiating or picking up energy from an incident EM field. Such a transmission line will pick up common mode energy and will reject difference mode energy, whether twisted or not.

Perhaps you are thinking of separate wires - not bonded together in a flat cable. In that case, twisting helps because it pulls the wires closer together. Or maybe you are thinking of signal pair in a bundle. In that case, yes, twisting certainly helps. But neither of these are done in RC.

RC planes are rather unique from an EMI/EMC stadpoint in that our cables do not run along conductive structures, as is common in instrumentation and computers. I suspect your experiences in other technologies are leading you to false conclusions.

BTW, RadicalRC sells twisted wire by the foot. I expect that if one wants, Dave will make up servo extension, adapters, etc using twisted wire. (This does not change my opinion. Suppliers are providing twisted wire to satisify the market, not because twisted wire is better.)
JPMacG is offline  
Reply With Quote
Old 12-17-2004, 11:40 AM
  #20  
dirtybird
My Feedback: (5)
 
Join Date: Jan 2002
Location: San Tan Valley, AZ
Posts: 5,768
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

ORIGINAL: mglavin


It has been measured and observed in countless situations I have solved for pilots, on paid projects during design and verification (board level changes right up through cable configuration changes etc on many projects), on RPV-based multiple communications protocol issues, electromagnetic bearing control, GPS/DGPS communications (specifically ignition and communications EMI/RFI on spray aircraft), I could go on
and on.

The bottom line is a measurable increase in headroom, which everyone can use these days. The justification for not doing it would be those who claim to not have a problem. To those I will rent an onboard pulse emission detector to record just how many times in any given flight they were not communicating with their aircraft. Then they can go and perform simple changes and see the results for themselves...
Just try to remember that we don't have sensitive communications equipment onboard our RC aircraft like RPV's and UAV's. The only thing we are worried about is EMC to the drive pulse of the servos.
dirtybird is offline  
Reply With Quote
Old 12-17-2004, 11:43 AM
  #21  
JNorton
My Feedback: (2)
 
JNorton's Avatar
 
Join Date: Jan 2002
Location: Coopersville, MI
Posts: 4,326
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

This is what I thought we were talking about. Individual twisted strands that make up a cable, not twisted flat cable.
http://www.nesail.com/detail.php?productID=1147
John

BTW, RadicalRC sells twisted wire by the foot. I expect that if one wants, Dave will make up servo extension, adapters, etc using twisted wire. (This does not change my opinion. Suppliers are providing twisted wire to satisify the market, not because twisted wire is better.)
That will teach me to post during lunch and not read the full post. Ah well another source for twisted cable.
Attached Thumbnails Click image for larger version

Name:	Zx71107.jpg
Views:	7
Size:	36.6 KB
ID:	203979  
JNorton is offline  
Reply With Quote
Old 12-17-2004, 12:17 PM
  #22  
JPMacG
My Feedback: (2)
 
Join Date: Jan 2002
Location: Ivyland, PA
Posts: 2,277
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Yes, that is what I am referring to as twisted wire - maybe I should have said twisted cable. RadicalRC sells the same stuff.
JPMacG is offline  
Reply With Quote
Old 12-17-2004, 01:07 PM
  #23  
lex2bits
Senior Member
My Feedback: (12)
 
lex2bits's Avatar
 
Join Date: Apr 2004
Location: ALBUQUERQUE, NM
Posts: 229
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Re: Servo Wire

Thank you gentlemen for the URL's, I can take it from here.

Ray
lex2bits is offline  
Reply With Quote
Old 12-20-2004, 12:29 AM
  #24  
Forgues Research
Senior Member
My Feedback: (7)
 
Forgues Research's Avatar
 
Join Date: Dec 2001
Location: Glen Robertson, ON, CANADA
Posts: 3,453
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

ORIGINAL: mglavin

As usual there are several points of view on the validity and or application of various techniques used to rig our models, below is another.

The main reasons OEM's do not use, let alone suggest twisted lead, is cost. The whole process of manufacturing anything made out of ribbon based electrical wire is cost. The whole process is automated, including the testing (if they are actually tested that is). Alas the suggestion (by an OEM) that twisted leads may enhance product performance leaves them open to litigation (this is a no-brainer).

Fact is, oodles and oodles of pilots are using none other than OEM-style (ribbon) cabling, and their systems are not (at least visually)exhibiting lack of control integrity as they merrily pirouette through blue yonder. The point is, as it always should be, is to apply those things that will increase RF operational headroom IN THE EVENT that it might come in handy! It may be the difference between landing your bird safely after that ignition GND strap is no longer grounded (but still creating one helluva spark), or looking for a trash bag.

Another fact. Control or signal integrity, better yet immunity to extraneous EMI/RFI is enhanced by allowing conductors to see that same extraneous noise equally. I have seen it, measured it, and applied it not only to our hobby/sport but on projects within the electronics industry. This is not rocket science.

Technically what occurs is that all the conductors are subject to energy that is associated with EMI/RFI. Because there are 2 vectors (90 degrees opposed) within EMI/RFI, or any electro-magnetic wave for that matter, twisting physically associates all 3 conductors to the same level of energy in both vectors, allowing energy to rise and fall equally. One or more twists per inch is adequate @ 72MHz.

What motivates me to respond are those who ignore the evidence, and wish to increase their own level of security by publicly stating that their systems have worked for years, THEREFORE, there can not be a problem. I think everybody should be given a pulse emission detector to just see how many times while you are painting the sky, your communications link fails...and you don't even know it let alone see it. It would probably cause a lot of you to re-think just how you fly.

Sorry everyone for getting antsy...but we are talking about relatively inexpensive 0.60-sized run-of-the-mill aircraft, but big, mean, and RF-noisy aerobats that cost big cabbage. It is simple things like this that everyone can do to enhance safety, not to mention the longevity of one your pride-and-joys.
Your right Michael, but no problems if you were to use Fiber Optic extensions , right???

Roger

Forgues Research
Forgues Research is offline  
Reply With Quote
Old 12-20-2004, 10:05 AM
  #25  
mglavin
My Feedback: (31)
 
Join Date: Nov 2001
Location: Elverta, CA
Posts: 5,295
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Servo extension wire?

Yes, The fiber optic extensions are another option which has proven to work well.
mglavin is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service