Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Strobe wiring

Matronics Email Lists Forum Index -> Europa-List

View previous topic :: View next topic

Author Message

TELEDYNMCS(at)aol.com
Guest

Posted: Fri Feb 20, 2009 6:10 am Post subject: Strobe wiring

In a message dated 2/20/2009 3:02:52 A.M. Eastern Standard Time,  europa-list(at)matronics.com writes:

  	  Quote: 	
		  >>>>>I know that this may be a little late for those of    you who have already 

bought their strobe power units, but my installation    works well without 

any interference. I have Whelen equipment and I mounted    an HTS power 

supply at each wing tip. They are mounted on removable panels    on the 

bottom surface. There is a weight penalty of about 1 pound compared    to a 

single HDA power supply in the fuselage but all the high voltage    cables 

are short and at the tip. No  problems.<<<< 	
  

 Hey John and all,

  

 Follwing the K.I.S.S. principle, I used a single Whelen  strobe power supply mounted to one of the vertical baggage bay  support members under the port side of the baggage bay and my install  does not cause any audio interference whatsoever. Access to the power  supply is through the port access cover in the baggage bay floor. The  power supply fires strobes on the wing tips with the cables routed from the  power supply along the bottom side of the baggage bay, then along  the sides of the baggage bay in the cockpit in fiberglass raceways which  extend from the baggage bay bulkhead forward to the rear of the door  sill. I installed these raceways along and over the fuselage  seams on the sides of the baggage bay, covering the seam, as well as providing a  conduit for wiring. The wires then pass down into the backrest and out the  side of the fuselage through grommeted holes in the fuselage  sides just behind the spar opening in the side of the fuselage. The  raceways I made were molded over a piece of 1.5" PVC pipe  cut lengthways to produce a 1/3rd round shape. Then with the PVC taped to a  piece of plywood, 3 layers of 'bid were used to make the molding. A 1/2" flange  was left either side of the rounded part to leave a bonding  flange for bonding to the inside side of the fuselage. 

  

 My system is quiet as a mouse without the faintest hint of strobe tick.  The secret to keeping your strobes quiet first and foremost is how you  ground the shield wires on the strobe high tension feeder cabling. The shield  wires should be grounded only on the power supply end. I crimped, then  soldered a ring terminal to the shield wire at the power supply end of the  strobe wires, then landed the ring terminal under one of the mounting  screws for the power supply so that the shield wire has continuity with the  power supply case (which is grounded). Do not ground the other end of the shield  wire at the light. If you do, you will create a loop antenna and a host of  problems will follow. 

  

 I used six pin Molex plugs and sockets at the wing roots and  fuselage sides so that I would be able to disconnect the strobe and Nav  light wiring when the wings are removed. The shield wire must also be  carried through at this point. At the light end, I simply cut the shield  wire off even with the cable jacket and stuck a piece of heat shrink tubing  on the strobe cable to make it look pretty, allowing the strobe  feeder wires to carry through a few inches beyond the cable jacket. The strobe  feeder wires exit the end of the heat shrink, along with the NAV wires which are  routed on the outside of the strobe cable, taped to the strobe cabling  about every 6" along the length of the strobe cable and then carry  on to the NAV light. I also installed 6 pin Molex plugs at the  light to make for easy removal of the light if and when it fails, but the shield  does not need to be included here. The plug/socket on the light end makes  for easy removal of the light fixture for replacement of the strobe and NAV  bulbs when the time comes or replacement of the fixture should it become  damaged, but this step could be omitted. Another thing that is very  important is to not route any other wiring with your radio and  intercom audio wires, especially the strobe feeds and the trim motor  wiring. Keep all other wiring separated from your audio wires by at least a few  inches.

  

 I've installed Whelen strobe/Nav combo lights, grounding the shield in  this manner, in 3 different airplanes thus far and all three are/were quiet  as a mouse. 

  

 Hope it helps!

  

 Regards,

  

 John  Lawton

Whitwell, TN (TN89)

N245E -  Flying

 A Good Credit Sco22736x1201267884/aol?redir=http:%2F%2Fwww.freecreditreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D668072%26hmpgID%3D62%26bcd%3DfebemailfooterNO62"> See yours in just 2 easy steps!

  [quote][b]

rparigor(at)suffolk.lib.n
Guest

Posted: Fri Feb 20, 2009 10:14 am Post subject: Strobe wiring

Hi John"The secret to keeping your strobes quiet first and foremost is how you  ground the shield wires on the strobe high tension feeder cabling."I HATE YOU!!! Buying a Whelen power supply that dosen't exhaust noise form anywhere and everywhere. What sort of homebuilder are you? Not wanting to spend weeks tangling with noise.From what I now understand, first and foremost is choosing a power supply that is quiet. Believe it or not on the Kunzleman, the quietiest thing about it is the high voltage output! I am not saying that if you don't ground the high voltage shield to box ground you won't get a little noise, but it is nothing compared to what comes out of the box, or what gets onto the power lines and radiates into the antenna and will get right into the cable if the cable is paralleled to power lines.One thing we found out, is shielded cable is a much better antenna than twisted pair for the supply line!We ended getting two Kuntzleman power supplies and are mounting them at wingtips. Makes no difference BTW if i use 12" or 25 feet of the wire supplied by Kuntzleman for high voltage, just that if you don't ground it, it makes a little noise and if battery runs down a little, will stop double flashing quicker with longer high voltage run.Fooling last night got box to stop breaking squelch with antenna at about 4 feet, so that is fine with power supplies mounted by wingtips.Fooling with various chokes and capacitors, got twisted pair going to battery to only break squelch if antenna is about 12" away. We also found that connecting the scope probe that is not connected to the scope completly eliminates all noise in radio! Art fooled on line a bit to figure out what is in probe, will get some more stuff to fool with.Don't have proper torroids or capacitors, but thus far looks like will be able to lick RF jumping off power lines.Bob N. from Aeroelectric sent out some filters to try out as well. Gut feeling is they will do the trick (at) 2.9 oz each.Local IA swears by Whelen in TC, said he has noise problems with all others. I am gonna have to grab a plane taxing by and throw scope on it just to see, the Kuntzleman has hash and sharp peaks. Choke we tried eliminates all hash, sharp peaks need just a little more work.Ron Parigoris   [quote][b]

rampil

Joined: 04 May 2007
Posts: 870

Posted: Fri Feb 20, 2009 1:18 pm Post subject: Re: Strobe wiring

Come now Ron,



Don't you remember the total lack of noise on my radios also?

I have a Whelan comet flash too.

_________________
Ira N224XS

jrgowing(at)bigpond.net.a
Guest

Posted: Sat Feb 21, 2009 10:56 am Post subject: Strobe wiring

John

  

 I am pleased to hear your system goes so well as I have put mine in the  same way except that I used auto connectors for the wires.

  

 I remember your nice set-up well since my visit with my daughter some many  years back!

  

 However I am still slugging away at building!

 Rotax 912 UL S arrived during the week.

  

 JR (Bob) Gowing UK Kit 327 in Oz

 [quote]   ---

frans(at)paardnatuurlijk.
Guest

Posted: Sun Feb 22, 2009 8:38 am Post subject: Strobe wiring

rampil wrote:

 	  Quote: 	
		   

 

 Come now Ron,

 

 Don't you remember the total lack of noise on my radios also?

 I have a Whelan comet flash too.


	


Because of the discussion about strobe noise, I got slightly worried so

I decided to test my setup, which was just finished. I was particularly

worried since I have a high power strobe, with one strobe bulb on the

fin, just a short distance away from the antenna...

So, today was strobe testing day.



I have an AVI-PAK strobe power supply, probably the most powerfull

strobe unit available (51.5 joules / 70 Watts).

Mounted under the ceiling just behind the D-panel.

I have three strobes: one on the fin, and two at the wingtips. The one

on the fin gets the most power, it alternates with the wingtip strobes

which share the power together.



Radio is a Garmin (Apollo) SL-30, plus a Vertex handheld.

Antenna is home-built, mounted in the fin, quite similar to the

Europa-antenna, but just a little bit more broadband.



The wiring for the strobes: From the strobe power supply directly via

the top to the fin. For the wingtips, the wiring goes via the back of

the doors to the rear wing pin, where I have installed a connector.

The rest of the cables of the airplane (including coax) are located on

the bottom.



Results:

Strobes at full power did not break the squelch. Neither on the Garmin

SL-30, neither on the Vertex handheld radio.

Next test was with squelch open. Strobe system was not audible at all.

NAV system (VOR and glidescope) could not be tested as there is no VOR

within receiving distance.

So far I'm happy with the result. 



I think the key of all this is:

1) Proper shielding of the cables. All strobe lines are shielded at the

housing of the strobe power supply, and nowhere else (also not at the

end near the strobe bulbs).

2) Keeping the setup symmetrical (hence the location underneath the

center of the top).

3) Keep coax and strobe cables as far as possible separated.

4) Ground and power leads for the strobe are not shared with anything

else. Even the navigation lamps (same housing as strobes) have their own

power leads, which follow a different routing than the strobe cables.

5) Make sure the antenna is tuned properly, and the coax cable properly

RF-decoupled.



About the latter: I have the coax cable run through torroids near the

antenna, and near the rear bulkhead I have some of the cable tightly

coiled up (ten turns) on a lightweight 5cm plastic tube. This to block

any RF travelling on the outer part of the coax. This blocks radiation

inside the airplane, and also reduces sensitivity for noise generated

inside the airplane. I think decoupling near the antenna is not enough,

as the coax will pick up RF again just behind the torroids because of

its close distance to the antenna. Hence the additional coil near the

rear bulkhead.



-- 

Frans Veldman

Rowland_Carson

Joined: 04 Jul 2008
Posts: 155
Location: Cheltenham, England

Posted: Sun Feb 22, 2009 9:03 am Post subject: Strobe wiring

At 2009-02-22 17:36 +0100 Frans Veldman wrote:



 	  Quote: 	
		  I have the coax cable run through torroids near the

antenna, and near the rear bulkhead I have some of the cable tightly

coiled up (ten turns) on a lightweight 5cm plastic tube


	


Frans - what type of cable are you using? I understand some coax will 

not like a bend radius as tight as 25mm.



I appreciate your thorough description of your installation and the 

good results it gives.



regards



Rowland

-- 

| Rowland Carson    http://home.clara.net/rowil/

| <rowil(at)clara.net>          ... that's Rowland with a 'w' ...

fklein(at)orcasonline.com
Guest

Posted: Sun Feb 22, 2009 9:51 am Post subject: Strobe wiring

Frans...thank you for your clear description of your system and its  

performance.



On Feb 22, 2009, at 8:36 AM, Frans Veldman wrote:

 	  Quote: 	
		  

 I have three strobes: one on the fin, and two at the wingtips. The one

 on the fin gets the most power,



 The wiring for the strobes: From the strobe power supply directly via

 the top to the fin.


	


 	  Quote: 	
		   4) Ground and power leads for the strobe are not shared with anything

 else. Even the navigation lamps (same housing as strobes) have their  

 own

 power leads, which follow a different routing than the strobe cables.


	


Did you separate the strobe wiring for your wingtip from that for your  

position lights? Do you then have separate connectors for your strobes  

and position lights at the wing root?



I too have a tail strobe...a nice little combo (strobe/LED position)  

unit from Kuntzelmann. It came with 25 feet of 5 wire shielded cable... 

3 for the strobe; 2 for the LEDs...



You seem to be suggesting that it would be best practice to toss the 5  

wire cable and use separate 3 wire shielded for the strobe and route  

it separate from the position light wiring.



Please confirm,



Fred

A194



-- 

This message has been scanned for viruses and

dangerous content by MailScanner, and is

believed to be clean.

frans(at)paardnatuurlijk.
Guest

Posted: Mon Feb 23, 2009 2:13 am Post subject: Strobe wiring

Fred Klein wrote:



 	  Quote: 	
		   Did you separate the strobe wiring for your wingtip from that for your

 position lights? Do you then have separate connectors for your strobes

 and position lights at the wing root?


	


I also received a 5 wire cable, but did not use it. Instead, I used

separate cables for the strobes and LEDs. It was lighter as well, as the

5-wire cable I received was rather heavy.



Think about it this way: The purpose of the shield of the cable is to

shield the outside world from the bad things happening on the inside of

the cable. But if you put the ground wire and power supply for the LED's

within this enclosure, these wires are not shielded for the bad things

happening on the adjacent wires, and they will happily pick up all noise

and bring it into your electrical system.



And yes, my strobe/LED combo's already had separate connectors for the

strobes and LED's.



For the electrical connection between the wings to the fuselage I use a

single 24 pole connector, one half of it bolted to the fuselage, the

other half on a flexible cable emerging near the wing spar. In this

cable, everything runs closely together, but only for a short distance.

And  of course, the strobewires are still shielded.



Oh, and I forgot to mention it because I thought it to be obvious, but

now I think about it maybe not: As the shield is to be connected to the

strobe power supply housing only, and nowhere else, you need at least a

4 pole connector between the wing and fuselage. The shield is to be

treated as a seaparate wire onces it leaves the strobe power supply. If

you were to use a 3 pole connector between fuselage and wing, and

reattach the shield to ground at that point, you defeat the whole

purpose of the shield between the strobe power supply and wing

connector. This will create a lot of electrical noise within the

aircraft. Maybe this is why some people experience so much problems with

a in-fuselage-mounted strobe power supply?



Maybe you wonder why I used 24 pole connectors: It soon adds up. 4 wires

for the strobe (including shield). 2 wires for the position lights. Then

some wires for the aileron trim, provisions to install a heated pitot

heat in the future, and a shielded cable for a future camera mount on

the wing. Further a short-cut between two pins, so I can install a

warning lamp that lights up when the wing connectors are not properly

connected.

The connector on the fuselage is also used to connect to ground power

13,7 Volts when the airplane is not rigged. This way I keep the

batteries topped up during storage, and also have a few power resistors

inside that generate a tiny amount of heat, just enough to keep moisture

out of the ship. And it makes it easy to play with the electronics on

board, without having to worry about the batteries.



You might think about all this before closing the wings. It is good to

have some spare wires inside the wings.  



-- 

Frans Veldman

frans(at)paardnatuurlijk.
Guest

Posted: Mon Feb 23, 2009 2:26 am Post subject: Strobe wiring

Rowland Carson wrote:

 	  Quote: 	
		  > I have the coax cable run through torroids near the

> antenna, and near the rear bulkhead I have some of the cable tightly

> coiled up (ten turns) on a lightweight 5cm plastic tube

 Frans - what type of cable are you using? I understand some coax will

 not like a bend radius as tight as 25mm.

Just some regular RG-58.

The problem with bending too much is that it pulls the center conductor

off its center. This will theoretically create a little bit of loss.

However, if you don't do this over a very long distance, and especially

over the frequencies we aviators use, the loss is neglicible. Higher

frequencies (like your transponder is using) are much more prone to

losses. For VHF, don't worry about cable losses.

-- 

Frans Veldman

rparigor(at)suffolk.lib.n
Guest

Posted: Mon Feb 23, 2009 4:06 am Post subject: Strobe wiring

Hi Frans



"I have the coax cable run through torroids near the

antenna, and near the rear bulkhead I have some of the cable tightly

coiled up (ten turns) on a lightweight 5cm plastic tube. This to block

any RF travelling on the outer part of the coax. This blocks radiation

inside the airplane, and also reduces sensitivity for noise generated

inside the airplane. I think decoupling near the antenna is not enough,

as the coax will pick up RF again just behind the torroids because of

its close distance to the antenna. Hence the additional coil near the

rear bulkhead."



If you don't mind I have a few questions:

*I have a Bob Archer big "E" model SA-006 in the vertical fin for Becker transceiver, will adding torroids decrease performance of this antenna? Will adding 10 turns to this antenna decrease it's performance?

*Same question as prior but using Advanced Aircraft Electronics Dipole antenna? (someone said it is a folded dipole??)

*I understand you did 10 turns at rear bulkhead to deal with strobe RF near that location. The antagonist on my install is the DC power wires of two Kuntzleman power supplies mounted at the wingtips. I have an aft mounted battery, and will have strobe power supply wires meeting up with battery cables just about at the passenger headrest. The positive battery cable will run on the starboard seam of fuse. I want to run my two radio antenna cables along side my fat wire #4 aluminium positive battery cable forward. In my case would it be preferable to do 10 turns and torroids after antenna cable parts company paralleling battery wire (near radio)?



Thx.

Ron Parigoris



BTW 100n capacitor/s helped alittle for noise in radio and a little for largest spike looking on scope. The torroid helped a little with noise in radio and a lot with lower frequency noise looking at scope. I need to order some more torroides as I think what I had on hand was a little too big.

Visit -  www.EuropaOwners.org

frans(at)paardnatuurlijk.
Guest

Posted: Mon Feb 23, 2009 6:23 am Post subject: Strobe wiring

rparigoris wrote:



 	  Quote: 	
		   If you don't mind I have a few questions: *I have a Bob Archer big

 "E" model SA-006 in the vertical fin for Becker transceiver, will

 adding torroids decrease performance of this antenna? Will adding 10

 turns to this antenna decrease it's performance?


	


This works with all antenna's. In a good design, the antenna-cable is

passive, is just to transfer the RF energy, and is not used to radiate

it. However, the electrons do not always understand our intentions, and

will happily follow the outside of the coax cable, if the antenna is not

pure symmetrical. Torroids/coils block the radiation of the outside of

the coax cable.



I would toss the Bob Archer antenna away, for the following reasons:



1) A half-wave dipole antenna is the best radiator. The Bob Archer

E-antenna is nice for airplanes where there is no room for a dipole

antenna. But in the vertical fin of the Europa, there is enough space

for a half-wave dipole antenna. Despite its simplicity, nothing really

beats a half-wave dipole antenna. Anything with a different shape is

always a compromise. It is just a matter of physics, despite all kind of

marketroids trying to tell you into something different. The Bob Archer

antenna can be a fine antenna, if you lack the size for a normal dipole

antenna, but this does not apply to the Europa.



2) The best place in the Europa for a VHF antenna is in the vertical

fin. This is the location which has the best separation from all kind of

noise sources, keeps the radiation as far as possible away from

sensitive electronics in the instrument panel, and keeps the antenna as

far away as possible from variable influences (crew, luggage, fuel)

which can dynamically alter the VSWR and radiation pattern. Also, there

are not many (none!) cables which must pass the antenna, as all other

electronics is located before the fin. The Bob Archer antenna does not

fit into the fin, forcing you to use a less optimal antenna location.



3) The standard polarization of aviation communications is vertical

(hence the vertical orientation of the antenna). Any antenna with bend

shapes in the "dipole-section" introduces some horizontal component in

the polarization. This energy is useless, as the station on the other

end will only receive/transmit the vertical component. Worse, most of

the electrical noise in our little airplanes comes from horizontal

orientated cables, and are transmitting horizontal polarised noise. By

keeping the antenna as vertical as possible, you null out most of the

noise sources. And during transmissions, a pure vertical antenna does

not induce much RF in horizontal orientated cables.

I suspect that a Bob Archer antenna has a strong horizontal element, so

stay away from it, unless you have no room for a pure vertical antenna.



A folded dipole has about a similar performance as a normal dipole, but

with just a little bit more bandwidth. But that comes with the cost of a

spoiled impedance, making it necessary to use some kind of transformer

with its own penalties (weight, costs, loss).

And any trick to broaden the bandwidth will negatively affect the

radiation efficiency of the antenna.



In my setup, I made a dipole antenna from aluminium parts, with a small

T-section on top and bottom. This broadens the bandwidth just enough to

get a good overall SWR over the entire communications band. It fits

nicely into the fin. This could also be achieved with a folded dipole,

but "my" setup is lighter, easier, and more economical.  If you can't

imagine what I did, I can make a picture.



Just don't forget there aint anything like a free lunch. Any antenna

with a claimed "gain", will suffer somewhere in its radiation pattern.

The only way to create gain, is to take energy from somewhere else and

focus it in a certain direction. Antenna's with gain are very usefull...

provided that you aim the lobe with the gain to the destination. In our

airplanes however we have no use for gain, as our communication should

be received/transmitted in all directions equally.

Compare it with a light bulb. You can't get more light from the

lightbulb with lenses and reflectors, but you can certainly create

"gain". This "gain" however always create dark spots in the radiation

pattern.

A vertical dipole has a very uniform circular radiation pattern and this

is again a reason why a dipole is the best antenna for aircrafts.

If you manage to find something that has more gain in all directions

compared to a dipole, you have found something that will change the laws

of physics forever. 

-- 

Frans Veldman

fklein(at)orcasonline.com
Guest

Posted: Mon Feb 23, 2009 10:20 am Post subject: Strobe wiring

On Feb 23, 2009, at 2:11 AM, Frans Veldman wrote:



 	  Quote: 	
		   Maybe you wonder why I used 24 pole connectors:


	


 	  Quote: 	
		   It soon adds up.


	


Frans...as do so many things associated w/ our audacious endeavors.



BTW, did you receive my progress report and the photos of the wing  

root fairings?...there were 10 which may have overloaded your email.



Fred

-- 

This message has been scanned for viruses and

dangerous content by MailScanner, and is

believed to be clean.

rparigor(at)suffolk.lib.n
Guest

Posted: Thu Feb 26, 2009 11:32 am Post subject: Strobe wiring

Hi Frans



I just received torroids from Aircraft Spruce (for Quickie Antenna kit). Do you by chance know why one side of the torroids are painted white? The torroid was painted green by Mfg. then they painted one side white.



If I slip them on antenna cable (no multi turn choke style wrapping going on), is there a prefered way to install with regard to white painted side?



Another question on your install, you put 10 turns and more torroids by baggage bulkhead, could you have put those 10 turns and more torroids by radio?



I appreciate info you have given!



Thx.

Ron Parigoris

Visit -  www.EuropaOwners.org

frans(at)paardnatuurlijk.
Guest

Posted: Thu Feb 26, 2009 1:06 pm Post subject: Strobe wiring

rparigoris wrote:

 	  Quote: 	
		   

 <rparigor(at)suffolk.lib.ny.us>

 

 Hi Frans

 

 I just received torroids from Aircraft Spruce (for Quickie Antenna

 kit). Do you by chance know why one side of the torroids are painted

 white? The torroid was painted green by Mfg. then they painted one

 side white.


	


I have to admit that I'm not an expert on torroids. I think this is just

a color coding, to describe the parameters of the torroid. For our

purpose, these parameters are not really critical.



 	  Quote: 	
		   If I slip them on antenna cable (no multi turn choke style wrapping

 going on), is there a prefered way to install with regard to white

 painted side?


	


They are equal on both sides.



 	  Quote: 	
		   Another question on your install, you put 10 turns and more torroids

 by baggage bulkhead, could you have put those 10 turns and more

 torroids by radio?


	


No. You want to isolate the antenna from the outside of the cable. If

you would put the torroids on the radio end, this would mean that the

entire length of the antenna cable is granted to receive and radiate to

the adjacent cables. This is exactly what you would like to prevent.



Let me know what difference you experience with these changes.



-- 

Best regards,

Frans Veldman

rparigor(at)suffolk.lib.n
Guest

Posted: Sun Mar 08, 2009 3:38 am Post subject: Strobe wiring

Thx. to all who replied to our strobe noise thread.

We managed to tame down strobe noise from Kuntzleman strobe units to a very acceptable level on Saturday!

We tried a lot of things, picture #24 tells what worked:

http://www.europaowners.org/modules.php?set_albumName=album278&op=modload&name=gallery&file=index&include=view_album.php

The clamp on cores on the "high voltage" side made a big difference second only to moving power supplies to wingtips. 



Ron Parigoris

Visit -  www.EuropaOwners.org

Display posts from previous:

	Matronics Email Lists Forum Index -> Europa-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum