Today's Message Index:
----------------------
1. 07:23 AM - However (Fergus Kyle)
2. 07:32 AM - Ground is ground? (Fergus Kyle)
3. 12:26 PM - Re: Electric Bob-Battery Contacter and (Robert L. Nuckolls, III)
4. 12:40 PM - Two questions-- (Eric M. Jones)
5. 01:51 PM - Re: RFI and Grounds... (Robert L. Nuckolls, III)
6. 10:19 PM - Re: Two questions-- (Robert L. Nuckolls, III)
Message 1
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--> AeroElectric-List message posted by: "Fergus Kyle" <VE3LVO@rac.ca>
"--> AeroElectric-List message posted by: Charles Brame
--> <charleyb@earthlink.net>
90 degree BNC Connectors would make my antenna connections easier and more
hidden. Do such critters exist? Is there a reasonable source for 90
connectors?Any pros or cons to their use?
Charlie RV-6A N11CBSan Antonio"
Remember, Charlie,
No offence, but if you're not familiar with coaxial cable
and its connectors,
[a] You are interested in 50 ohm connectors only, to match cable,[b]
Your primary cable is RG58, RG 400 or similar (for size), and
[c] You may want to study and practice attaching connectors to coax cable
because (1) it's not simple, and (2) 95% of antenna trouble is found in the
connectors, especially after a while unles properly done.
Happy hunting,
Ferg
Europa A064
Message 2
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| Subject: | Ground is ground? |
--> AeroElectric-List message posted by: "Fergus Kyle" <VE3LVO@rac.ca>
"> --> AeroElectric-List message posted by: Scott Bilinski
<bilinski@kyocera-wireless.com>>
> This brings up a question I have been thinking about for a while now and>
that is, Isnt ground, ground?"
Scott,
The simple answer is "No, it's not".
"In the case of a metal airplane the whole> thing is a ground. How does it
matter where things are grounded? Isnt it> all the same?"
The ideal answer is:
"--> AeroElectric-List message posted by: Duncan McBride
<duncanmcbride@comcast.net>
You are a perfect candidate for the Book. See http://www.aeroelectric.com/
and buy Bob Nuckoll's book. It has answered a hundred questions such as
yours, and knowing it's on the shelf makes me feel a little less guilty for
the help I get on this list"
Happy Landings,
Ferg
Message 3
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| Subject: | Re: Electric Bob-Battery Contacter and |
Relay Questions
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 11:11 PM 5/23/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Rick Fogerson" <rickf@cableone.net>
>
>Hi Bob,
>Re the B&C battery contactor: Your wiring diagrams seem to indicate that a
>diode goes between the Battery post and the smaller terminal closest to
>it. My contactors actually have a plain wire jumper between the Battery
>post and the smaller terminal closest to it and the diode wired between
>the two small terminals. Is is this correct?
see
http://www.aeroelectric.com/Catalog/switch/switch.html#s701-1
and
http://www.aeroelectric.com/Catalog/switch/s701-1l.jpg
>Re the S704-1 relay (used to switch power for >7A power when batterys are
>located in the rear): Does it matter which one of the two solenoid
>terminals that power is hooked to? The one closest to the com terminal or
>the one below it?
no
>Also, your wiring diagram for the relays shows the NO terminal jumpered to
>a solenoid terminal and the two solenoid terminals connected with a 1N4005
>diode. Are these external jumpers and diodes that I have to add or are
>these internal to the relay?
they are external See http://www.aeroelectric.com/articles/s704inst.jpg
Bob . . .
Message 4
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--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
1) Along with keyswitch orientation. How about the little keyway on the toggle
switch bushing. I always put them on the OFF/Down side. Is there a standard I
don't know about?
2) Is there anyone kind enough to send me a copy of DO-160. I don't have the membership
dues right now but I promise to join when I can.
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones@charter.net
"Mankind faces a cross-roads. One path leads to despair and utter hopelessness.
The other, to total extinction. Let us pray we have the wisdom to choose correctly."
--Woody Allen
Message 5
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| Subject: | Re: RFI and Grounds... |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 05:47 PM 5/23/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: Canyon <steve.canyon@verizon.net>
>
>Scott Bilinski wrote:
> >This brings up a question I have been thinking about for a while now and
> >that is, Isnt ground, ground? In the case of a metal airplane the whole
> >thing is a ground. How does it matter where things are grounded? Isnt it
> >all the same?
>---
>Not trying to play games here -- simply proposing a couple things to
>ponder. I have trained many ETs through the years and their training
>all started with a couple simple ideas to ponder.
>
>1. Is there any such thing as a short circuit?
This is a common term in the vernacular of many
disciplines. In the airplane business, it's more often
referred to has a "hard fault" . . . but irrespective
of vernacular and venue it's understood to be an
unwanted conduction path producing current flows in
potentially hazardous ways. They often exceed the
path's rated current capability by many times.
A hard fault on a bizjet's ni-cad can get you several
thousands of amps "short circuit", "hard fault" or any
thing else one chooses to call it.
The only limitation on potential current flow in a
hard fault are path resistances which cannot be
(except in a super conduction environment) zero
ohms. 2,000A from a 24V battery suggests a path
resistance of 12 milliohms which has to include
internal resistance of the battery and all other
conductors (including ground) that are part of
the closed loop.
>2. Can two wires occupying the same physical space and carrying equal
>currents of opposite polarity radiate energy externally?
A theoretical hypothesis at best but assuming you could twist
a couple of 80AWG wires together without breaking them and
drive them as closed loop, the magnetic field around
the pair would be exceedingly low . . . but probably
not zero.
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
Message 6
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| Subject: | Re: Two questions-- |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 03:43 PM 5/24/2003 -0400, you wrote:
>--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>
>1) Along with keyswitch orientation. How about the little keyway on the
>toggle switch bushing. I always put them on the OFF/Down side. Is there a
>standard I don't know about?
Our diagram numbers assume key-way up. Of course, this only affects
the progressive transfer switches. All others are mirror image
for operation and can mount either way.
>2) Is there anyone kind enough to send me a copy of DO-160. I don't have
>the membership dues right now but I promise to join when I can.
DO-160 is a 3-ring binder of some magnitude . . . it's
several hundred pages I think. I'm trying to track down
a .pdf version but no luck so far.
Bob . . .
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