Today's Message Index:
----------------------
1. 06:06 AM - Re: VHF Nav/GS Duplexer (Jared Yates)
2. 06:25 AM - Re: VHF Nav/GS Duplexer (Robert L. Nuckolls, III)
3. 06:45 AM - Re: VHF Nav/GS Duplexer (Harley)
4. 06:47 AM - Re: VHF Nav/GS Duplexer (Jared Yates)
5. 08:48 AM - Re: Questions about protecting the 4AWG wire in a remote battery installation. (Robert L. Nuckolls, III)
6. 08:55 AM - Re: VHF Nav/GS Duplexer (Robert L. Nuckolls, III)
7. 08:59 AM - Re: VHF Nav/GS Duplexer (Robert L. Nuckolls, III)
8. 09:03 AM - RG-400 source (Robert L. Nuckolls, III)
9. 04:33 PM - All you can eat buffets (Fulgham)
10. 09:51 PM - Re: All you can eat buffets (rayj)
11. 10:05 PM - Re: All you can eat buffets (rayj)
Message 1
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| Subject: | Re: VHF Nav/GS Duplexer |
Would an antenna like that need a balun, and what kind of gap would be
acceptable between the two elements?
On Fri, Aug 5, 2011 at 11:36 PM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> nuckolls.bob@aeroelectric.com**>
>
>
> At 08:50 PM 8/5/2011, you wrote:
>
>> Thanks everyone, I'm intrigued by the DIY duplex option, assuming that I
>> can find the parts. I especially like Bob's idea of a design that minimizes
>> losses to the VHF signal, since that was my only motivation for a separate
>> GS antenna. The airplane is a Bearhawk, which is a tailwheel tube and
>> fabric fuselage with a aluminum skin from the instrument panel to the nose
>> bowl.
>>
>
> Okay, Cessna put tens of thousands of GS antennas just
> above the compass centered on the windshield. A simple
> dipole 17" long fed in the center with 50 ohm coax
> will perform quite well.
>
> We had a fancy, clear plastic molded housing that
> contained a copper foil strip. A short length of RG174
> (itty-bitty 50 ohm coax) fed the center and took the
> feed-line under the windshield and upholstery trim. I think
> it spliced onto RG58 to take the signal on to the
> GS receiver.
>
> If you can manage RG400's larger diameter, it would
> be the material of choice for getting the GS signal
> down to your panel mounted receiver.
>
> I proposed a methodology for fabricating a GS antenna
> in the chapter on antennas . . . but forget the toroid
> cores . . . they add no observable value.
>
>
> Bob . . .
> ////
> (o o)
> ===========o00o=(_)=o00o======**==
> < Go ahead, make my day . . . >
> < show me where I'm wrong. >
> ==============================**==
>
>
Message 2
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| Subject: | Re: VHF Nav/GS Duplexer |
At 08:00 AM 8/6/2011, you wrote:
>Would an antenna like that need a balun,
Technically, it is "best" . . . practically,
you wouldn't see any difference in performance
if it did not have one.
> and what kind of gap would be acceptable between the two elements?
. . . minimum practical. Actually, you can fabricate
a nifty antenna just from coax cable.
In this case, you clean off the outer jacket of your
feedline about 11". If it's a double shielded coax,
strip of the outer layer of shield too.
Pull center conductor out of the remaining shield
as illustrated here:
http://www.aeroelectric.com/articles/shldwire/shldwire.html
Stretch the center conductor and remaining
braid out into a dipole and trim each to 9.5"
per side.
Glue to 1/4" wood or plastic dowel 17" long. Just
spot it in a few places to fixture it on the dowel.
Then put pieces of heat shrink over each
leg of the dipole to "dress it up".
This technique eliminates the process-sensitive
and never pretty junction between antenna elements
an the feedline. It's all one piece.
Bob . . .
Message 3
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| Subject: | Re: VHF Nav/GS Duplexer |
Bob...
A little inconsistency here...I think...the length of the antenna
elements and the dowel don't match.
Did you mean to cut the shield and center conductor to 8.5 inches
long each and use a 17 inch dowel, or to use a dowel 19 inches
long for the 9.5" element length?
Or leave two inches of the center of the coax unattached and
hanging at something like a "Y"? Or one inch of each element
hanging over each end of the dowel?
Harley
-----------------------------------------------------------------
> . . . minimum practical. Actually, you can fabricate
> a nifty antenna just from coax cable.
>
> In this case, you clean off the outer jacket of your
> feedline about 11". If it's a double shielded coax,
> strip of the outer layer of shield too.
>
> Pull center conductor out of the remaining shield
> as illustrated here:
>
> http://www.aeroelectric.com/articles/shldwire/shldwire.html
>
> Stretch the center conductor and remaining
> braid out into a dipole and trim each to 9.5"
> per side.
>
> Glue to 1/4" wood or plastic dowel 17" long. Just
> spot it in a few places to fixture it on the dowel.
> Then put pieces of heat shrink over each
> leg of the dipole to "dress it up".
>
> This technique eliminates the process-sensitive
> and never pretty junction between antenna elements
> an the feedline. It's all one piece.
>
> Bob . . .
>
Message 4
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| Subject: | Re: VHF Nav/GS Duplexer |
Awesome, that sounds like the best solution so far! I have some hefty
spanwise steel structure up at the top of the windshield. In this
application should I be worried about being close to those?
On Sat, Aug 6, 2011 at 9:20 AM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> nuckolls.bob@aeroelectric.com**>
>
> At 08:00 AM 8/6/2011, you wrote:
>
>> Would an antenna like that need a balun,
>>
>
> Technically, it is "best" . . . practically,
> you wouldn't see any difference in performance
> if it did not have one.
>
>
> and what kind of gap would be acceptable between the two elements?
>>
>
> . . . minimum practical. Actually, you can fabricate
> a nifty antenna just from coax cable.
>
> In this case, you clean off the outer jacket of your
> feedline about 11". If it's a double shielded coax,
> strip of the outer layer of shield too.
>
> Pull center conductor out of the remaining shield
> as illustrated here:
>
> http://www.aeroelectric.com/**articles/shldwire/shldwire.**html<http://www.aeroelectric.com/articles/shldwire/shldwire.html>
>
> Stretch the center conductor and remaining
> braid out into a dipole and trim each to 9.5"
> per side.
>
> Glue to 1/4" wood or plastic dowel 17" long. Just
> spot it in a few places to fixture it on the dowel.
> Then put pieces of heat shrink over each
> leg of the dipole to "dress it up".
>
> This technique eliminates the process-sensitive
> and never pretty junction between antenna elements
> an the feedline. It's all one piece.
>
> Bob . . .
>
>
Message 5
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| Subject: | Re: Questions about protecting the 4AWG wire in |
a remote battery installation.
>Bob,
>
>Seems like your solution is to put the battery contactor near the
>battery, and the starter contactor on the firewall with the bus feeder
>and alternator wired to that.
Yes . . .
>That is what I'll do, but doesn't that leave the 4awg wire between the
>two contactors unprotected or will the battery contactor fail before the
>wire does? Are you saying that this wire doesn't need to be protected
>because it can be switched off by the pilot?
Exactly. These 'fat wires' are part of the power
distribution between major components and do not
represent an operational hazard for overload. The
artfully installed fat wire will not suffer a hard
fault that puts the wire at risk . . . it generally
is 'self clearing' and burns away the edge of any
former where the grommet has failed.
In a type certificated airplane, FAR23.1357
allows fat-wires to go 'un protected'. See:
http://www.aeroelectric.com/Reference_Docs/FAA/Part23_electrical_A.pdf
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
Message 6
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| Subject: | Re: VHF Nav/GS Duplexer |
At 08:41 AM 8/6/2011, you wrote:
>Bob...
>
>A little inconsistency here...I think...the length of the antenna
>elements and the dowel don't match.
>
>Did you mean to cut the shield and center conductor to 8.5 inches
>long each and use a 17 inch dowel, or to use a dowel 19 inches long
>for the 9.5" element length?
>
>Or leave two inches of the center of the coax unattached and hanging
>at something like a "Y"? Or one inch of each element hanging over
>each end of the dowel?
No, stretch the whole thing out on a dowel of appropriate
length . . . in this case the 9.5" was a typo, should
be 8.5" and 17" overall. Thanks for the heads-up!
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
Message 7
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| Subject: | Re: VHF Nav/GS Duplexer |
At 08:43 AM 8/6/2011, you wrote:
>Awesome, that sounds like the best solution so far! I have some
>hefty spanwise steel structure up at the top of the windshield. In
>this application should I be worried about being close to those?
Technically, yes. Ignore them for now. Space away as far
as sensibilities and craftsmanship will allow and give
it a try. Close proximity of the conductive structure will
electrically lengthen the antenna . . . so after installation
the purist would trim to new resonance after installation.
In this case, I don't think it's going to make much operational
difference.
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
Message 8
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|
I made a good buy on a wad of RG400 cable assemblies.
I'll be offering RG-400 cut to length with connectors
installed for $1.50/ft. Some long lengths (~10' or longer)
may be supplied with a mated pair of SMA crimp connnectors
to splice two shorter lengths. Connector choices will
include BNC cable male, BNC cable female, SMA cable male
and SMA cable female.
Will let the List know when the product is listed on
the website catalog.
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
Message 9
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| Subject: | All you can eat buffets |
Subject: All you can eat buffets
All you can eat buffets - HYSTERICAL, especially the part
about Indian food.
His humor is off the wall! This is the epitome of a good
humorous speech without a bit of nasty language from a comedian. Talk
about using his body as a visual aid! Great!
ALL-YOU-CAN-EAT BUFFETS: click below.
http://www.stumbleupon.com/su/1B4AZI
--
Message 10
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| Subject: | Re: All you can eat buffets |
Please do not send me items which do not pertain to aircraft electronics
or electrical systems.
Raymond Julian
Kettle River, MN
"And you know that I could have me a million more friends,
and all I'd have to lose is my point of view." - John Prine
On 08/06/2011 06:27 PM, Fulgham wrote:
> *Subject:* All you can eat buffets
>
>
> All you can eat buffets - HYSTERICAL, especially the part about Indian food.
>
> His humor is off the wall! This is the epitomeof a good humorous speech
> without a bit of nasty language from a comedian. Talk about using his
> body as a visual aid! Great!
>
> *ALL-YOU-CAN-EAT BUFFETS: click below.*
>
> http://www.stumbleupon.com/su/1B4AZI
>
>
> --
>
>
>
> FREE Animations for your email - by IncrediMail! Click Here!
> <http://www.incredimail.com/?id=619263&did=10500&ppd=2723,201107241428,9,1,603980311805460181&rui=125498726&sd 110806>
>
Message 11
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| Subject: | Re: All you can eat buffets |
Sorry list, I intended to send this to the person who sent it to me.
Apologies to all.
Raymond Julian
Kettle River, MN
"And you know that I could have me a million more friends,
and all I'd have to lose is my point of view." - John Prine
On 08/06/2011 11:46 PM, rayj wrote:
>
> Please do not send me items which do not pertain to aircraft electronics
> or electrical systems.
>
> Raymond Julian
> Kettle River, MN
>
> "And you know that I could have me a million more friends,
> and all I'd have to lose is my point of view." - John Prine
>
> On 08/06/2011 06:27 PM, Fulgham wrote:
>> *Subject:* All you can eat buffets
>>
>>
>> All you can eat buffets - HYSTERICAL, especially the part about Indian
>> food.
>>
>> His humor is off the wall! This is the epitomeof a good humorous speech
>> without a bit of nasty language from a comedian. Talk about using his
>> body as a visual aid! Great!
>>
>> *ALL-YOU-CAN-EAT BUFFETS: click below.*
>>
>> http://www.stumbleupon.com/su/1B4AZI
>>
>>
>>
>>
>> --
>>
>>
>>
>> FREE Animations for your email - by IncrediMail! Click Here!
>> <http://www.incredimail.com/?id=619263&did=10500&ppd=2723,201107241428,9,1,603980311805460181&rui=125498726&sd 110806>
>>
>>
>
>
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