nuckolls.bob(at)aeroelect
Guest
|
 Posted: Sat Feb 28, 2009 11:00 am Post subject: Why are antenna torroids painted different colors? |
 |
|
At 11:56 PM 2/25/2009, you wrote:
| Quote: | Just received torroids from Aircraft Spruce for Quickie antenna kit PN 11-0990 that I want to fool with on my Europa project.
They are painted green then the Mfg. painted the face on one side white.
Why is one face painted white and do I need to concern myself with which way I install them on RG-400 antenna cable?
|
They are not "polarity" sensitive. My best guess is that
this was a material identification marking scheme offered
by the original specifier of the core.
Cores can be fabricated in dozens of "standard" and an
infinite number of custom mixes depending on design
goals for the end product. As an example, here's a sampling
of common materials offered by one popular supplier
of cores to the hobby and manufacturing venues.
https://www.amidoncorp.com/categories/7
I've worked with cores in the past that were stripped
with bands of color not unlike a resistor. The
practice of color coding is becoming much less common
with the development of high-speed laser marking
machines. If parts we receive today are marked at
all, it will be with some combination of characters
unique to that part.
With respect to the usefulness of cores over an
antenna feedline, the practice is problematic.
Many commercial cables are fabricated with such
devices installed.
[img]cid:.0[/img]
We read dozens of articles/conversations on the web
that suggest they are "good" and just as many who say
they're a "waste of time".
http://tinyurl.com/d8sakj
None the less, that doesn't discourage train-loads
of the things being offered and sold in a host
of types and sizes.
http://www.thefind.com/instruments/info-ferrite-core-radio
Bottom line is that any product that is vulnerable
to external noises -OR- is a potential generator
of deleterious noises should be filtered at the
wall of the box. We had a discussion about this concerning
strobe supply noises last week.
Any time the INSTALLER improves on the operation
of some system by putting band-aids of any kind on
interconnecting wires . . .there's something seriously
wrong with the design goals of the antagonist, victim
or both.
Sliding a few ferrite beads over an antenna coax have
been shown to produce no practical effects . . . i.e.
did not improve on the system's ability to coexist with
lots of other potential antagonists or victims. The
benefits ARE measurable . . . if you've got a screen
room and a boat-load of good test equipment. But the
effects are so small as to be difficult to measure.
The interference conditions we're likely to encounter
in practice will be so severe that the effects provided
by a few beads have a poor probability of solving
a problem.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
| Description: |
|
| Filesize: |
37.33 KB |
| Viewed: |
847 Time(s) |
|
|
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
