Today's Message Index:
----------------------
1. 02:57 AM - Re: Garmin GPS Antenna (GT)
2. 02:57 AM - Re: Source for Garmin GPS 400 antenna (GT)
3. 02:57 AM - Re: Re: Source for Garmin GPS 400 antenna04 (GT)
4. 08:30 AM - Re: Load dump TVS (Paul Messinger)
5. 08:59 AM - Re: More on the electrical robustness of the XCOM 760 ()
6. 09:15 AM - personal ELT (Troy Scott)
7. 10:30 AM - Re: personal ELT (Richard McCraw)
8. 10:45 AM - Re: personal ELT (Jim Oke)
9. 03:05 PM - B-lead fuse vs. circuit breaker (Roger Evenson)
10. 03:38 PM - Re: B-lead fuse vs. circuit breaker (Dan Branstrom)
11. 09:12 PM - Re: personal ELT (James E. Clark)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Garmin GPS Antenna |
--> AeroElectric-List message posted by: "GT" <Gilles.Thesee@ac-grenoble.fr>
> Hello Gilles, If appearance is your primary concern why not mount the
antenna
> on a small aluminum shelf suspended underneath either the glare shield or
a
> bit further forward under the cowling? I assume that neither the glare
shield
> or cowling are made of metal.
>
> The antenna for my Garmin 430 is out of sight on such a shelf aft of the
> firewall and forward of the glareshield. It works great.
>
> One additional benefit of having the antenna mounted on an aluminum shelf
is
> that the aluminum partially shields the bottom of the antenna from
electronic
> garbage happening below the shelf.
Hey "OC",
Thank you for your message. Interesting suggestion indeed. Nevertheless our
primary structure and cowlings are carbon fiber, ie conductive material, so
we can't do that. But had the cowlings been 'glass I'm sure I'd follow your
advice.
Cheers,
Gilles
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Source for Garmin GPS 400 antenna |
--> AeroElectric-List message posted by: "GT" <Gilles.Thesee@ac-grenoble.fr>
> > As our intention is to mount the antenna on the glareshield, I would
like
> to
> > find a less bulky and preferably dark colored model.
>
> I covered a white GPS antenna with black fabric years ago because the
white
> reflected in the windshield badly. It worked fine.
>
> Cliff A&P/IA
Cliff,
Thanks for the input. As there is no fabric in our airplane (only zolatone)
we'll try to find a more discreet model.
Regards,
Gilles
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Source for Garmin GPS 400 antenna04 |
--> AeroElectric-List message posted by: "GT" <Gilles.Thesee@ac-grenoble.fr>
> I'm using the noncertified (small, round, black) GPS antenna from
http://www.gretzaero.com/ for my GPS295. The information on the web page
implies this antenna should work with the GNS400 series. I've been happy
with the service from Gretz Aero.
Roy,
Thanks for your reply. I've mailed Gretz Aero to ask them about the specific
use with the Garmin GPS 400 receiver.
Regards,
Gilles
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Load dump TVS |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
The ref below is for automotive protection.
Note that automobiles have different electrical requirements. For example
they must be able to take the boost start 24V from TWO series 12V batteries.
Thus the LDP24A device is rated for 24V (nominal) use.
Our problem is we need to protect at a lower voltage upper limit and much
tighter range of voltages so the automotive solution will not work "off the
shelf".
When you search the ST site for this device you end up with 3 hits. ALL 3
are relevant and interesting to read (all are PDF files).
Progress is being made on the design and testing of both internal and
external regulated alternators in various simulated loading conditions based
on Bob's schematics to determine the magnitude of the "load dump" and how to
deal with it with minimal cost etc.
Expect more very late this month. At most only 10% of my time can be spent
on this and it takes a lot of time to build a proper setup to get reliable
results.
Paul
----- Original Message -----
From: "Paul Messinger" <paulm@olypen.com>
Subject: AeroElectric-List: Load dump TVS
> --> AeroElectric-List message posted by: "Paul Messinger"
<paulm@olypen.com>
>
> As I promised here is the device I mentioned a several weeks ago as being
> designed specifically for alternator load dump.
>
> LDP24A and the data sheet can be found by searching
> at www.st.com
>
> An interesting related app note AN554 is also at the st site. Provides
> detailed design info!
>
> www.findchips.com will find dist stock for the LDP24A
>
>
> Paul
>
>
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | More on the electrical robustness of the XCOM 760 |
--> AeroElectric-List message posted by: <beecho@beecho.org>
Hi Rob and anyone else interested in XCom products.. BEWARE!
I bought an intercom from them and also had them make up a wiring
harness to connect the intercom and switch between two Microair 760s.
The intercom appears to be good, clear, light and small. HOWEVER,
harness they supplied is totally inadequate. First of all, many the
cables were mislabeled which of course meant they were connected
incorrectly by me. I emailed Michael Coates, their honcho, and was told
he would get right back to me. Did he, NO. I then asked him if I could
return the harness to him or at least could he send me a wiring diagram.
NO RESPONSE. I have attempted to contact him many times and asked at
least if he would send back the $$ I had paid for the harness. NO
RESPONSE.
Since then, Microair has sent me a proper wiring diagram and I find that
XCom did it entirely wrong, used the wrong kind of switch, etc.
BEWARE...
Tom Friedland, California, Europa
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Rob W
M Shipley
Subject: AeroElectric-List: More on the electrical robustness of the
XCOM 760
--> AeroElectric-List message posted by: "Rob W M Shipley"
<rob@robsglass.com>
My question to MCP was motivated by my own interest in possibly buying
this com. It is built by a team of engineers at least some of whom were
originally involved in the Microair - hence the reference to this.
My email .........
Hi Michael,
A current thread on the Aeroelectric list at the moment is the risk of
load dumps if a generator is disconnected whilst under load. As part of
this discussion the tolerance of different avionics to withstand voltage
excursions has been of interest.
The prevailing certified standard for this is DO 160 (US) and it was
mentioned that the Microair falls well short of this.
Could you comment on the XCOM760 and whether it meets the DO 160 levels
of resistance and if not what is the level of voltage/time resistance
designed into the radio?
Rob
From Michael Coates <mcoates@mcp.com.au
>From our engineer..... hopefully this answers your question.... its
all rocket science to me so i had to refer it to those in the know.
Thanks Michael
Ken Luxford wrote:
Michael,
While the nominal maximum input voltage of the XCOM760 is 16 volts,
all of the components in the DC input filter are rated at 35 volts. The
onboard 10V regulator has a maximum input voltage of 37 volts and the
onboard 5V regulator has a maximum input voltage of 45 volts.
The comments regarding TVS (Transient Voltage Suppressors) are valid
and I have had personal experience of them failing in the manner
described.
Perhaps Bob would comment on how satisfactory a level of protection
this might be.
==
==
==
==
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> AeroElectric-List message posted by: "Troy Scott" <tscott1217@bellsouth.net>
Gentlemen,
SO I guess the short answer is: Don't spend very much for an ELT. ? I'm
thinking I might just order an Ameri-King ELT AK-450. Any particular reason
NOT to? I'll probably also carry a personal EPIRB. I always had one in my
sailboats (never NEEDED it....).
Regards,
Troy Scott
tscott1217@bellsouth.net
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> AeroElectric-List message posted by: "Richard McCraw" <rmccraw@wcvt.com>
Forgive me if this detail has been mentioned before (I'm new to the list),
but there exist TSO'd ELTs that use off-the-shelf batteries -- D-cells, I
think. I have such an ELT in my Bonanza.
All you have to do is use batteries that carry an expiration date and
replace them before they expire. Makes battery replacement a whole lot
cheaper than it was in my old ELT!
Rick McCraw
BE36, RV7 (a-building)
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: personal ELT |
--> AeroElectric-List message posted by: Jim Oke <wjoke@shaw.ca>
Yes, good idea! An old, inexpensive, not very effective, but "approved" ELT
is your legal belt, while the newer, more expensive, but non-approved EPIRB
(406 MHz ??) is the set of suspenders that you can probably rely on to get
yourself found if the worst comes to pass.
The politics of introducing new technology is often just as interesting as
the technology itself. With ELTs the advantages of the 406 MHz systems are
well-known and fully understood. Governments however are loath to pass a
regulation that makes millions of dollars of old ELTs obsolete overnight and
requires voting/taxpaying aircraft owners to buy new 406 MHz ELTs at five
times the cost.
Jim Oke
RV-6A, RV-3
Wpg, MB
(Used to do the odd ELT search myself.)
----- Original Message -----
From: <richard@riley.net>
Subject: Re: AeroElectric-List: personal ELT
> --> AeroElectric-List message posted by: richard@riley.net
> >If you have a US registered aircraft, then FAR 91.207 applies:
> >FAR 91.207: Emergency locator transmitters.
> >(a) Except as provided in paragraphs (e) and (f) of this section, no
> >person may operate a U.S.-registered civil airplane unless --
> >
> > (1) There is attached to the airplane an approved automatic type
> >emergency locator transmitter that is in operable condition for the
> >following operations
> >
> >"Approved" means the ELT must have a TSO. EPIRBs don't have TSOs, as
> >far as I can tell.
>
> There's legal, and there's real.
>
> To be legal, I can use a piece of crap ELT that's been banging around my
> shop for a few years. Throw a new battery in it, it's legal. And it's
> almost useless in a real emergency.
>
> So, I add to that a personal EPIRB for about $800. Now I have something
> that might actually get me rescued. Nothing in the FAR's that says I
> can't have an EPIRB.
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | B-lead fuse vs. circuit breaker |
--> AeroElectric-List message posted by: "Roger Evenson" <revenson@comcast.net>
In Chapter 17, Bob suggests a B-lead fuse instead of a circuit breaker, "for a
much lower resistance..between alternator (the noisiest device) and battery (the
best filter)."
Why? What's this mean? What's the significance of this design feature?
Thanks for answering this beginner's question. Roger.
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: B-lead fuse vs. circuit breaker |
--> AeroElectric-List message posted by: "Dan Branstrom" <danbranstrom@verizon.net>
Somebody will state this better (and correct me if I'm wrong): The circuit
breaker has a low amount of resistance because it depends on the heating of
a bi-metallic strip, which bends and trips the breaker, and heat = use of
energy. A fuse has an even lower amount of resistance, because the heat
produced by current flowing through it rises much faster at the limit of its
ability to carry that current. Since the fuse doesn't heat up much until it
gets close to the limit, it has a much lower resistance.
To smooth out the noise of the alternator, you want the lowest resistance
possible. With a low resistance, there is less possibility for minor
fluctuations (noise) to occur, because more of the fluctuations from the
alternator are absorbed by the battery. If you put a resister between the
two of them, there is more possibility for a voltage differential between
the alternator and the battery. The more voltage difference (particularly
from a pulse) the more noise you will get.
Dan Branstrom
----- Original Message -----
From: "Roger Evenson" <revenson@comcast.net>
Subject: AeroElectric-List: B-lead fuse vs. circuit breaker
> --> AeroElectric-List message posted by: "Roger Evenson"
<revenson@comcast.net>
>
> In Chapter 17, Bob suggests a B-lead fuse instead of a circuit breaker,
"for a much lower resistance..between alternator (the noisiest device) and
battery (the best filter)."
>
> Why? What's this mean? What's the significance of this design feature?
>
> Thanks for answering this beginner's question. Roger.
>
>
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> AeroElectric-List message posted by: "James E. Clark" <james@nextupventures.com>
Comment below ..
[SNIP]
>
> Forgive me if this detail has been mentioned before (I'm new to the list),
> but there exist TSO'd ELTs that use off-the-shelf batteries -- D-cells, I
> think. I have such an ELT in my Bonanza.
>
> All you have to do is use batteries that carry an expiration date and
> replace them before they expire. Makes battery replacement a whole lot'
Bill I don't have the regs before me on this (so I **may** be WRONG!) but I
think you might want to double check that on the batteries.
We are in the middle of condition inspection on our RV6 and changed out out
D-cells. The ones we took out had not expired and theones we put in expire
in 2011! It is probably not a good idea to leave those things in there for
much beyond a year (let alone 7) as they might corrode and fail you JUST
when you need them.
You can always use the batteries that you take out in a flashlight. That's
our plan ... taking those suckers out EVERY 12 months and getting some
useage out of them.
> cheaper than it was in my old ELT!
I also changed out the ELT in my certified plane to be able to do the same.
The purchase of the unit cost me less than what I think it cost me to get
the old one tested twice.
James
>
> Rick McCraw
> BE36, RV7 (a-building)
>
>
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|