Today's Message Index:
----------------------
1. 06:14 AM - Re: copper foil groundplane (Mike Welch)
2. 07:08 AM - Re: schematic for a Challenger II (user9253)
3. 07:26 AM - Re: Re: copper foil groundplane (RGent1224@aol.com)
4. 08:35 AM - Re: Re: copper foil groundplane (Mike Welch)
5. 08:40 AM - Re: Re: schematic for a Challenger II (Doug Ilg)
6. 08:48 AM - Re: Re: copper foil groundplane (Robert L. Nuckolls, III)
7. 11:02 AM - Re: copper foil groundplane (n81jg@aol.com)
8. 11:44 AM - Re: copper foil groundplane ()
9. 02:34 PM - Re: copper foil groundplane (checkn6)
10. 03:58 PM - Re: "miracle antenna" (Robert L. Nuckolls, III)
11. 04:13 PM - Internal comm antennas for composites (Robert L. Nuckolls, III)
12. 06:12 PM - Re: schematic for a Challenger II (user9253)
13. 08:42 PM - Re: Re: schematic for a Challenger II (Richard E. Tasker)
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| Subject: | RE: copper foil groundplane |
Hi Bob=2C
Thanks for the detailed and informative response. Yes=2C I am very much
a DIY person.
I don't really have the $100 for the Miracle antenna (end-fed halfwave dipo
le)=2C so I guess I'll have to stick with a homemade one.
So far=2C I'm still leaning toward the belly mount dipole=2C and making a
spoke style grid of copper foil=2C where the steel rod mast mounts in the
center of the grid. I'll sure to get a good ground of the groundplane to t
he tube frame.
Does more than four legs of a cu foil groundplane make it better? Or=2C
is that just a waste of copper tape?
I'm curious. After I get this antenna constructed=2C mounted and finishe
d=2C how does one check it's adjustment with a SWR meter. I mean=2C there
aren't many things you could do to the mast=2C except cut off a little. Bu
t=2C what if you cut off too much?
Could you possibly explain the actual nuts and bolts of using an SWR mete
r=2C and how it can allow a guy to improve his antenna's performance?
One more thing.... I am also building a GlaStar=2C and bought the factor
y copper foil dipole antenna. I noticed it has triax cable=2C rather than
regular RG58. I assume this is because the extra layer of the triax acts a
s a balun. I meant to check out how the triax connects at the junction of
the two copper strips=2C but forgot=2C and mounted it in the tail and close
d it up.
For fiberglass airplanes that might use this type of "triax cable copper
foil dipole"=2C how and where is the triax soldered=2C if it's soldered at
all?
Thanks a lot!!
Mike Welch
The end-fed half-wave antenna has been around
for a long time and is a popular topic of
discussion and debate in the amateur radio
antenna forums. There's a particularly lucid
study of these beasties to be found at:
http://www.aa5tb.com/efha.html
Of course=2C this article is dealing with the lower
HF frequencies of interest to amateurs but the
physics scales nicely into the higher VHF range.
My sense is that while they can be "tuned" to
accommodate effects of installation=2C they're not
your grandpa's plug-n-play buggy whip. It's unlikely
that an end-fed half-wave stuck inside the fuselage
of a composite aircraft will be optimized out of the
box for that particular installation.
Having said that=2C we also know that antenna efficiency
in airplanes can be all over the map and still provide
satisfactory performance. I have no doubt that the
antenna offered has many "satisfied" users.
If the builder is not DIY shy=2C a few dollars in
materials can be crafted into an quarter-wave
over ground-plane antenna that will certainly
perform as well with more predictable results
for SWR. Getting to the center of a half-wave
dipole isn't hard if you put the center
half way up on the side of the fuselage and
wrap around the inside surface.
Distorting from a straight antenna will have
the effect of electrically lengthening the
antenna so trimming after installation with
some form of SWR instrument would be useful
. . . but probably wouldn't produce observable
differences in performance
I've just joined this group and have a couple of questions.
I have searched the archives=2C but finding my particular
answers is tough=2C to say the least. I'm getting very close to
installing the Icom A200 comm antenna in my tube & fabric
airplane (Kolb MkIII). I think I've chosen to go underneath
the fuselage=2C between the main gear legs=2C with the 23" steel
rod mast pointing down and rearward.
That will probably work as well as anything else.
You can ground the feedline shield to the steel-tube
structure.
Bob . . .
_________________________________________________________________
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| Subject: | Re: schematic for a Challenger II |
Doug,
The way to let others open a file is to save it on a file sharing website and then
provide a link to it on Matronics. I use WindowsLive. Even though it is
designed for photo sharing, you are allowed to share files with various extensions.
4AWG seems big for a small engine unless the battery is a long way from the
starter.
Placing diodes in parallel across the relays and contactors (with arrows pointing
towards positive) will protect the controlling switches from arcs and sparks.
Switching the grounded side of the master contactor instead of the hot side
will minimize the number of hot wires running to the instrument panel.
An avionics switch is not recommended because if it fails, everything connected
to it stops working. In your case, there are only two items. If each has
its own on-off switch, then an avionics switch is not needed.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=294172#294172
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| Subject: | Re: RE: copper foil groundplane |
Check this out
_http://rst-engr.com/rst/catalog/airplane_antenna.html_
(http://rst-engr.com/rst/catalog/airplane_antenna.html)
Dick
In a message dated 4/14/2010 8:16:26 A.M. Central Daylight Time,
mdnanwelch7@hotmail.com writes:
Hi Bob,
Thanks for the detailed and informative response. Yes, I am very much a
DIY person.
I don't really have the $100 for the Miracle antenna (end-fed halfwave
dipole), so I guess I'll have to stick with a homemade one.
So far, I'm still leaning toward the belly mount dipole, and making a
spoke style grid of copper foil, where the steel rod mast mounts in the center
of the grid. I'll sure to get a good ground of the groundplane to the tube
frame.
Does more than four legs of a cu foil groundplane make it better? Or, is
that just a waste of copper tape?
I'm curious. After I get this antenna constructed, mounted and finished,
how does one check it's adjustment with a SWR meter. I mean, there aren't
many things you could do to the mast, except cut off a little. But, what
if you cut off too much?
Could you possibly explain the actual nuts and bolts of using an SWR
meter, and how it can allow a guy to improve his antenna's performance?
One more thing.... I am also building a GlaStar, and bought the factory
copper foil dipole antenna. I noticed it has triax cable, rather than
regular RG58. I assume this is because the extra layer of the triax acts as a
balun. I meant to check out how the triax connects at the junction of the
two copper strips, but forgot, and mounted it in the tail and closed it up.
For fiberglass airplanes that might use this type of "triax cable copper
foil dipole", how and where is the triax soldered, if it's soldered at all?
Thanks a lot!!
Mike Welch
The end-fed half-wave antenna has been around
for a long time and is a popular topic of
discussion and debate in the amateur radio
antenna forums. There's a particularly lucid
study of these beasties to be found at:
_http://www.aa5tb.com/efha.html
_ (http://www.aa5tb.com/efha.html) Of course, this article is dealing with
the lower
HF frequencies of interest to amateurs but the
physics scales nicely into the higher VHF range.
My sense is that while they can be "tuned" to
accommodate effects of installation, they're not
your grandpa's plug-n-play buggy whip. It's unlikely
that an end-fed half-wave stuck inside the fuselage
of a composite aircraft will be optimized out of the
box for that particular installation.
Having said that, we also know that antenna efficiency
in airplanes can be all over the map and still provide
satisfactory performance. I have no doubt that the
antenna offered has many "satisfied" users.
If the builder is not DIY shy, a few dollars in
materials can be crafted into an quarter-wave
over ground-plane antenna that will certainly
perform as well with more predictable results
for SWR. Getting to the center of a half-wave
dipole isn't hard if you put the center
half way up on the side of the fuselage and
wrap around the inside surface.
Distorting from a straight antenna will have
the effect of electrically lengthening the
antenna so trimming after installation with
some form of SWR instrument would be useful
. . . but probably wouldn't produce observable
differences in performance
I've just joined this group and have a couple of questions.
I have searched the archives, but finding my particular
answers is tough, to say the least. I'm getting very close to
installing the Icom A200 comm antenna in my tube & fabric
airplane (Kolb MkIII). I think I've chosen to go underneath
the fuselage, between the main gear legs, with the 23" steel
rod mast pointing down and rearward.
That will probably work as well as anything else.
You can ground the feedline shield to the steel-tube
structure.
Bob . . .
-List">http://www.matronics.com/Navigator?AeroElectric-List
ronics.com ww.matronics.com/contribution
____________________________________
The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with
Hotmail. _Get busy._
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| Subject: | RE: copper foil groundplane |
Dick=2C
I'm very familiar with Bob Weir's stuff=2C and in fact=2C I built one of
these copper foil antennas a few years ago. I haven't installed it yet. I
f I can find it=2C I think I'm going to go ahead and use it.
I built the mast out of fiberglass=2C with the copper foil sandwiched ins
ide it. The mast is then soldered to a BNC connector=2C and faired in with
more fiberglass. Finally=2C I sanded everything nice and smooth=2C and pa
inted it grey.
Thanks for the reference=2C tho.
Mike Welch
From: RGent1224@aol.com
Subject: Re: AeroElectric-List: RE: copper foil groundplane
Check this out
http://rst-engr.com/rst/catalog/airplane_antenna.html
Dick
In a message dated 4/14/2010 8:16:26 A.M. Central Daylight Time=2C mdnanwel
ch7@hotmail.com writes:
Hi Bob=2C
Thanks for the detailed and informative response. Yes=2C I am very much
a DIY person.
I don't really have the $100 for the Miracle antenna (end-fed halfwave dipo
le)=2C so I guess I'll have to stick with a homemade one.
So far=2C I'm still leaning toward the belly mount dipole=2C and making a
spoke style grid of copper foil=2C where the steel rod mast mounts in the
center of the grid. I'll sure to get a good ground of the groundplane to t
he tube frame.
Does more than four legs of a cu foil groundplane make it better? Or=2C
is that just a waste of copper tape?
I'm curious. After I get this antenna constructed=2C mounted and finishe
d=2C how does one check it's adjustment with a SWR meter. I mean=2C there
aren't many things you could do to the mast=2C except cut off a little. Bu
t=2C what if you cut off too much?
Could you possibly explain the actual nuts and bolts of using an SWR mete
r=2C and how it can allow a guy to improve his antenna's performance?
One more thing.... I am also building a GlaStar=2C and bought the factor
y copper foil dipole antenna. I noticed it has triax cable=2C rather than
regular RG58. I assume this is because the extra layer of the triax acts a
s a balun. I meant to check out how the triax connects at the junction of
the two copper strips=2C but forgot=2C and mounted it in the tail and close
d it up.
For fiberglass airplanes that might use this type of "triax cable copper
foil dipole"=2C how and where is the triax soldered=2C if it's soldered at
all?
Thanks a lot!!
Mike Welch
The end-fed half-wave antenna has been around
for a long time and is a popular topic of
discussion and debate in the amateur radio
antenna forums. There's a particularly lucid
study of these beasties to be found at:
http://www.aa5tb.com/efha.html
Of course=2C this article is dealing with the lower
HF frequencies of interest to amateurs but the
physics scales nicely into the higher VHF range.
My sense is that while they can be "tuned" to
accommodate effects of installation=2C they're not
your grandpa's plug-n-play buggy whip. It's unlikely
that an end-fed half-wave stuck inside the fuselage
of a composite aircraft will be optimized out of the
box for that particular installation.
Having said that=2C we also know that antenna efficiency
in airplanes can be all over the map and still provide
satisfactory performance. I have no doubt that the
antenna offered has many "satisfied" users.
If the builder is not DIY shy=2C a few dollars in
materials can be crafted into an quarter-wave
over ground-plane antenna that will certainly
perform as well with more predictable results
for SWR. Getting to the center of a half-wave
dipole isn't hard if you put the center
half way up on the side of the fuselage and
wrap around the inside surface.
Distorting from a straight antenna will have
the effect of electrically lengthening the
antenna so trimming after installation with
some form of SWR instrument would be useful
. . . but probably wouldn't produce observable
differences in performance
I've just joined this group and have a couple of questions.
I have searched the archives=2C but finding my particular
answers is tough=2C to say the least. I'm getting very close to
installing the Icom A200 comm antenna in my tube & fabric
airplane (Kolb MkIII). I think I've chosen to go underneath
the fuselage=2C between the main gear legs=2C with the 23" steel
rod mast pointing down and rearward.
That will probably work as well as anything else.
You can ground the feedline shield to the steel-tube
structure.
Bob . . .
-List">http://www.matronics.com/Navigator?AeroElectric-List
ronics.com
ww.matronics.com/contribution
The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with H
otmail. Get busy.
List href="http://www.matronics.com/Navigator?AeroElectric-List">http://w
ww.matronics.com/Navigator?AeroElectric-List
ms.matronics.com/">http://forums.matronics.com
tp://www.matronics.com/contribution">http://www.matronics.com/contribution
_________________________________________________________________
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otmail.
http://www.windowslive.com/campaign/thenewbusy?tile=multicalendar&ocid=
PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5
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| Subject: | Re: schematic for a Challenger II |
Joe,
Oops. I guess attaching the file was a faux pas. Sorry.
Would you say that 6AWG is good enough for the fat wires, then?
Another oops. Ihave those diodesacross the coils on my diagram. Sent the wrong
one.
Good point on switching the ground side. Will do.
For the avionics switch, both of the switched units(EFIS and radio) require external
switches. Wish they didn't. I'll consider separating them if I can find
enough room on the relatively small panel. (The switches I'd like to use are rather
large.)
Doug Ilg
Grumman Tiger N74818, College ParkAirport (KCGS), Maryland
Challenger II LSS LW (N641LGreserved)- kit underway at Laurel Suburban (W18)
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| Subject: | Re: RE: copper foil groundplane |
At 08:12 AM 4/14/2010, you wrote:
Hi Bob,
Thanks for the detailed and informative response. Yes, I am very
much a DIY person. I don't really have the $100 for the Miracle
antenna (end-fed halfwave dipole), so I guess I'll have to stick with
a homemade one.
I've had an antenna building article on my to-do list
for years. Unfortunately that list is long and the
antenna project is pretty far down. Suggest you start
with a manufactured "mount" like . . . .
http://tinyurl.com/y3a4lpf
This is an example of MANY similar products which
you can find at about any truck-stop on a major highway.
You can install the mating PL-259 coax connector
on your coax -OR- install a SO Male to BNC female
adapter to mate with your own installed BNC cable
male -OR- consider this pre-mfg assembly from
Radio Shack . . .
http://tinyurl.com/y7dzxpf
It has a PL-259 on one end that will mate with
your "truckers antenna mount". You can cut the
connector off the other end and install a cable
male to mate with your transceiver.
So far, I'm still leaning toward the belly mount dipole,
"dipole" or "vertical 1/4-wave"?
and making a spoke style grid of copper foil, where the steel rod
mast mounts in the center of the grid. I'll sure to get a good ground
of the groundplane to the tube frame. Does more than four legs of
a cu foil groundplane make it better? Or, is that just a waste of
copper tape?
Tests have shown that there's a diminishing return
on investment for adding radials to the ground plane.
To make a significant improvement one needs to double
the radials. The step from 4 is up to 8 . . . you can
see where that's taking us.
You'll need some sort of structural bracket
that grips a tube and supplies a suitable
flat against the inside surface of the fabric
for attaching the antenna. This bracket also be
suitable for grounding the coax shield to the
airframe. Getting robust connection to a ground
plane attached inside a fabric 'skin' is problematic.
The ship's existing metallic structure is a
reasonable substitute for the classic "spider
legs" ground plane.
I'm curious. After I get this antenna constructed, mounted and finished,
how does one check it's adjustment with a SWR meter. I mean, there
aren't many things you could do to the mast, except cut off a little.
Correct. If you were going to "go for the gold",
you'd make it extra long by about an inch and
then trim to length for best SWR at the selected
center frequency. The theroetical 1/4-wave centered
in the VHF comm band (129.5 Mhz) is 23.34 inches.
If you cut it to 22.34 inches the antenna is
calculated to center on 132.14 Mhz. So the
"tuning sensitivity" for this antenna is on the
order of 2.6 Mhz per inch of length. So trimming
say .1" at a time would let you "sneak up on it".
Alternatively, you can calculate a new length based
on measured center frequency using the 2.6"/MHz
sensitivity factor.
Now that we've fine tuned the theory, know also
that there are other factors that influence the
resonant frequency. An important one is a correction
for length/diameter ratio. I speak to this effect
in figure 13-6 of the 'Connection. If your antenna
rod is .125" diam stainless and is about 23" long,
then the l/d ratio is about 160. This translates
to an electrical "lengthening" of about 3.5% or
.81 inches. Gee, this translates to about 2 Mhz
shift in center frequency.
Further, bending your antenna aft for a rakish
appearance (or better ground clearance) has a
further lengthening effect. All this calculator
key-punching goes to demonstrate that the ideal
antenna is trimmed to length after installation
using some form of instrumentation.
Return on investment? The guy listening to your
transmitted signal wouldn't know the difference
between the "ideal" and "pretty close" antenna.
Further, DIRECTIONAL effects of airframe geometry
can have a PROFOUND effect on the very best of
antennas. This effect is discussed in the BALUN
construction article cited below.
Bottom line: 22" for a 1/4-wave stick is close
enough for government work. An SWR test at the
transceiver end of the feed line is most useful
as a gross check of antenna integrity. Check SWR
at say 1 Mhz steps from 118.0 to 135.0 and plot the
results. The "dip" in the plot shows the center
frequency of the antenna. The SWR shouldn't be
more than 3.0:1 over the full range of interest.
An antenna with a broken connection along the feed
line will have very high SWR numbers and probably
exhibit no clear "dip" in the plot.
But, what if you cut off too much?
That IS a problem only if you're pedantic about
getting the antenna performance centered on
129.5000000000 Mhz. If you "overshoot" a trimming
operation and the durn thing now centers at 131
Mhz, no big deal.
Could you possibly explain the actual nuts and bolts of using
an SWR meter, and how it can allow a guy to improve his antenna's
performance?
It's pretty simple. Use your ship's transmitter
as a signal source and plot measured SWR against
transmit frequency. When you're all done, the
SWR will be LOWEST at the design center. SWR
should not be more than 3:1 at the edges of
the band.
One more thing.... I am also building a GlaStar, and bought the
factory copper foil dipole antenna. I noticed it has triax cable,
rather than regular RG58. I assume this is because the extra layer
of the triax acts as a balun. I meant to check out how the triax
connects at the junction of the two copper strips, but forgot, and
mounted it in the tail and closed it up.
For fiberglass airplanes that might use this type of "triax cable
copper foil dipole", how and where is the triax soldered, if it's
soldered at all?
I've heard of this design but never had the opportunity
to run it through the lab. It's better than NO balun but
again, ROI is problematic. The outer shield could be
used two ways: Soldered to the inner shield 1/4-wave from
the antenna end only. This makes it a "bazooka" decoupling
sleeve.
http://tinyurl.com/y6xgese
Alternatively, it can solder to the inner shield 1/4-wave
away from the antenna as above. The other end of outer
shield solders to the center conductor at the antenna
end. This makes it a piece of transmission line. This
type of balun is easily synthesized without the use
of triaxial coax as shown here:
http://tinyurl.com/yytxwd3
I wouldn't discourage anyone from going for the best-
we-know-how-to-do in selection/fabrication, installation
and testing of antennas on the airplane. At the same
time, know that "missing the mark" by some small amount
is probably not a reason for ripping it out and starting
over.
Bob . . .
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| Subject: | Re: copper foil groundplane |
Check out Slim Jim and J-pole antennas on Google. They are end fed dipole
s.
John Greaves
VariEze N81JG
Redding, CA
-----Original Message-----
From: Mike Welch <mdnanwelch7@hotmail.com>
Sent: Tue, Apr 13, 2010 2:45 pm
Subject: RE: AeroElectric-List: copper foil groundplane
Doug,
No, I hadn't heard of this one. It sounds like this could be the perfec
t setup. Do you know how the wire is "oriented"? Can you just make a cir
cular loop, or ????
I do like the idea of this antenna, but since I'm between jobs right now
, funds are very scarce. Plus, I really wanted to make the antenna for my
plane, just for the experience.
Does anyone know of a DIY plan for this type of dipole end-fed com anten
na? What is in that little black box? (hopefully not some of that "specia
l smoke" that leaks out when you touch two wrong wires together!!)
If anyone knows of a way to make one these single wire dipole end-fed an
tennas, I'd sure appreciate a drawing or two.
Thanks again, Doug, for the tip!!
Mike Welch
Mike,
Have you looked at Miracle Antenna's Air Whip? http://www.miracleantenna.
com/AirWhip.htm It's a full dipole antenna that's made completely of flex
ible wire. It's also end-fed, so you don't need access to the middle of
the antenna for connection. You can put it anywhere in the fuselage that
's not shielded by conductive parts.
I'm not flying yet, but mine seems to work very well on the ground. It fi
ts quite well in the fiberglass nose cone of my Challenger. Based on a qu
ick look at a picture of a Kolb M3X, I'd guess you could do something simi
lar in your airplane. It might save you some of the hassle you're dealing
with.
FYI.
-Doug
Doug Ilg
Grumman Tiger N74818, College Park Airport (KCGS), Maryland
Challenger II LSS LW (N641LG reserved) - kit underway at Laurel Suburban
(W18)
From: Mike Welch <mdnanwelch7@hotmail.com>
Sent: Tue, April 13, 2010 1:15:25 PM
Subject: AeroElectric-List: copper foil groundplane
Hi guys,
I've just joined this group and have a couple of questions. I have sear
ched the archives, but finding my particular answers is tough, to say the
least.
I'm getting very close to installing the Icom A200 comm antenna in my tu
be & fabric airplane (Kolb MkIII). I think I've chosen to go underneath
the fuselage, between the main gear legs, with the 23" steel rod mast poi
nting down and rearward.
>
Hotmail is redefining busy with tools for the New Busy. Get more from your
inbox. See how.
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| Subject: | copper foil groundplane |
Found this. Just put in the freq and it tells you how long to make it.
Does that mean the length we're shooting for is the middle of the band?
http://www.m0ukd.com/Calculators/Slim_Jim/index.php
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
n81jg@aol.com
Sent: Wednesday, April 14, 2010 1:50 PM
Subject: Re: AeroElectric-List: copper foil groundplane
Check out Slim Jim and J-pole antennas on Google. They are end fed
dipoles.
John Greaves
VariEze N81JG
Redding, CA
-----Original Message-----
From: Mike Welch <mdnanwelch7@hotmail.com>
Sent: Tue, Apr 13, 2010 2:45 pm
Subject: RE: AeroElectric-List: copper foil groundplane
Doug,
No, I hadn't heard of this one. It sounds like this could be the
perfect setup. Do you know how the wire is "oriented"? Can you just
make a circular loop, or ????
I do like the idea of this antenna, but since I'm between jobs right
now, funds are very scarce. Plus, I really wanted to make the antenna
for my plane, just for the experience.
Does anyone know of a DIY plan for this type of dipole end-fed com
antenna? What is in that little black box? (hopefully not some of that
"special smoke" that leaks out when you touch two wrong wires
together!!)
If anyone knows of a way to make one these single wire dipole end-fed
antennas, I'd sure appreciate a drawing or two.
Thanks again, Doug, for the tip!!
Mike Welch
Mike,
Have you looked at Miracle Antenna's Air Whip?
http://www.miracleantenna.com/AirWhip.htm It's a full dipole antenna
that's made completely of flexible wire. It's also end-fed, so you
don't need access to the middle of the antenna for connection. You can
put it anywhere in the fuselage that's not shielded by conductive parts.
I'm not flying yet, but mine seems to work very well on the ground. It
fits quite well in the fiberglass nose cone of my Challenger. Based on
a quick look at a picture of a Kolb M3X, I'd guess you could do
something similar in your airplane. It might save you some of the
hassle you're dealing with.
FYI.
-Doug
Doug Ilg
Grumman Tiger N74818, College Park Airport (KCGS), Maryland Challenger
II LSS LW (N641LG reserved) - kit underway at Laurel Suburban (W18)
From: Mike Welch <mdnanwelch7@hotmail.com>
Sent: Tue, April 13, 2010 1:15:25 PM
Subject: AeroElectric-List: copper foil groundplane
Hi guys,
I've just joined this group and have a couple of questions. I have
searched the archives, but finding my particular answers is tough, to
say the least.
I'm getting very close to installing the Icom A200 comm antenna in my
tube & fabric airplane (Kolb MkIII). I think I've chosen to go
underneath the fuselage, between the main gear legs, with the 23" steel
rod mast pointing down and rearward.
>
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| Subject: | Re: copper foil groundplane |
Inside the magic box
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=294242#294242
Attachments:
http://forums.matronics.com//files/themiracleinside_131.jpg
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| Subject: | Re: "miracle antenna" |
At 04:32 PM 4/14/2010, you wrote:
>
>Inside the magic box
>
>Attachments:
>
>http://forums.matronics.com//files/themiracleinside_131.jpg
Hmmmm. . . . not especially impressive. I think I'll
write the folks an see if they'll send me an evaluation
sample.
Bob . . .
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| Subject: | Internal comm antennas for composites |
Check these data points . . .
http://davemorris.com/MorrisComLoop.cfm
http://www.aeroelectric.com/articles/Antennas/Popular_Antenna_Lore.pdf
http://www.aeroelectric.com/articles/ant_anal.pdf
http://www.aeroelectric.com/Pictures/Antenna/Figure_13-8.pdf
Bob . . .
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| Subject: | Re: schematic for a Challenger II |
> I guess attaching the file was a faux pas.
There is nothing wrong with the way that you did it. I was only trying to explain
how to share a drawing with the extension of sch.
> Would you say that 6AWG is good enough for the fat wires, then?
I do not know. It all depends on the current draw of the starter and length of
wire. My Rotax 912 comes with 8awg for the starter. What have others used on
your type of plane and engine? You could try smaller wire and if the engine
cranks too slowly, then replace the wire with a larger size.
I assume that your plane will be used for low and slow fun flying. As long as
failure of the avionics switch does not disable critical equipment, then having
one switch for two devices is OK. Separate switches are ideal but one switch
will work.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=294267#294267
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| Subject: | Re: schematic for a Challenger II |
Why is attaching a file a faux pas? Plenty of others do it. Yours was
quite small as attachments go... Attaching a 5MB file would be, in my
opinion, but an 84K file...
Dick Tasker
Doug Ilg wrote:
> --> AeroElectric-List message posted by: Doug Ilg<doug.ilg@verizon.net>
>
> Joe,
>
> Oops. I guess attaching the file was a faux pas. Sorry.
> Would you say that 6AWG is good enough for the fat wires, then?
>
> Another oops. I have those diodes across the coils on my diagram. Sent the
wrong one.
>
> Good point on switching the ground side. Will do.
>
> For the avionics switch, both of the switched units (EFIS and radio) require
external switches. Wish they didn't. I'll consider separating them if I can
find enough room on the relatively small panel. (The switches I'd like to use
are rather large.)
>
>
> Doug Ilg
> Grumman Tiger N74818, College Park Airport (KCGS), Maryland
> Challenger II LSS LW (N641LG reserved) - kit underway at Laurel Suburban (W18)
>
>
>
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