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Mounting and Wiring LSE Coils

bjdecker

Well Known Member
Ambassador
I am big fan of the Lightspeed Plasma III system. This is the third aircraft I've installed these on, and flown 1000+ hours without issue (...jinx...:))

However, there are certain parts of the system installation that I found to be sub-par:

1. Soldered on D-sub connectors.
2. Old systems - weird non-milspec wire from the flywheel sensor.
3. Cute but not useful mounts for the coils
4. #@!&* RG-400 for the primary wire leads.

--

#1 is easy to solve - cut off and use crimped-machined D-sub contacts
#2 replace wire with MIL-STD 27500, 20 ~ 22 Ga wire.
See attached for #3 & 4.

...and yes, adapting 2+Shield wire to a BNC connector isn't approved, but you can make it work and it's solid as heck.
 

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I am big fan of the Lightspeed Plasma III system. This is the third aircraft I've installed these on, and flown 1000+ hours without issue (...jinx...:))

However, there are certain parts of the system installation that I found to be sub-par:

1. Soldered on D-sub connectors.
2. Old systems - weird non-milspec wire from the flywheel sensor.
3. Cute but not useful mounts for the coils
4. #@!&* RG-400 for the primary wire leads.

--

#1 is easy to solve - cut off and use crimped-machined D-sub contacts
#2 replace wire with MIL-STD 27500, 20 ~ 22 Ga wire.
See attached for #3 & 4.

...and yes, adapting 2+Shield wire to a BNC connector isn't approved, but you can make it work and it's solid as heck.

Makes sense to me. I'm a fan of LSE, but I''d be interested as to what Klaus thinks of this set up:).......
 
What's the problem with the RG-400? I just made up a set, and it was easy and solid! Why is 2 shielded wires, and how did you make that work with a BNC connector?

To attach the terminal to the shielded part of the RG-400, you just unbraid the shielding with a pick, (like getting knots out of someone's hair with your fingers), then twist it up, trim it square, and crimp on a Blue terminal. Finish it off with shrink tube and it's perfect.
 
What's the problem with the RG-400?

It's too big, it's difficult to route, termination on the center conductor tends to break unless done perfectly, and then it will break... :)

RG-400 is intended to be terminated with TNC/BNC/similar connectors *not* crimp lugs.

...And now, talking out of the other side of my mouth...

To adapt a BNC to MIL-C-27500 type wire, strip ~5mm from the end of one of the wires (white), insert into center contact and crimp, cut other conductor (white/blue) a little short and strip back to braid, fold over - insert into connector with braid+conductor on outside body, slide crimp ferrule over braid and crimp. At the coil end of the wire, leave the shield floating at this end, trim back to jacket and cover with heat shrink, strip and terminate the two wires with PIDG FastOn .25" lugs.

Picture here for reference -- https://www.mouser.com/datasheet/2/418/7/ENG_CD_1634500_G1_baseFilename-2014755.pdf
 
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