Today's Message Index:
----------------------
1. 01:34 AM - Re: Recombinant Gas Batteries (Jim Jewell)
2. 05:15 AM - Re: GPS Antennas (Dennis O'Connor)
3. 05:17 AM - Re: GPS Antennas (Dennis O'Connor)
4. 05:32 AM - cranking amps vs. amp-hours (Gary Casey)
5. 07:22 AM - Re: Recombinant Gas Batteries (Walter Casey)
6. 07:28 AM - Re: cranking amps vs. amp-hours (John Rourke)
7. 08:17 AM - Re: GPS Antennas (Norman and Gretchen Howell)
8. 08:26 AM - Re: OV regulatro (Rhett Westerman)
9. 09:28 AM - Re: cranking amps vs. amp-hours (Robert L. Nuckolls, III)
10. 09:34 AM - Re: AeroElectric-List Digest: 26 Msgs - 12/30/02 (Mitch Williams)
11. 10:04 AM - Re: cockpit backup batteries (Robert L. Nuckolls, III)
12. 10:24 AM - Re: Re: AeroElectric-List Digest: 26 Msgs - 12/30/02 (Dennis O'Connor)
13. 10:52 AM - Re: GPS Antennas (Dennis O'Connor)
14. 10:55 AM - Re: Recombinant Gas Batteries (Robert L. Nuckolls, III)
15. 11:02 AM - Re: GPS Antennas (Robert L. Nuckolls, III)
16. 11:38 AM - Re: GPS receivers (Robert L. Nuckolls, III)
17. 11:45 AM - Re: OV protection (Robert L. Nuckolls, III)
18. 12:49 PM - second alternator (Paul Wilson)
19. 01:12 PM - Re: Re: OV protection (Rhett Westerman)
20. 02:33 PM - Re: GPS Antennas (Norman and Gretchen Howell)
21. 02:38 PM - Re: citabria triping overvoltage relay (Robert L. Nuckolls, III)
22. 03:26 PM - Alternator weights (Charles Brame)
23. 05:15 PM - Re: Alternator weights (Walter Casey)
Message 1
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| Subject: | Re: Recombinant Gas Batteries |
--> AeroElectric-List message posted by: "Jim Jewell" <jjewell@telus.net>
Hello Walter,
If you have a battery dealer or shop nearby. Go there and enquire about
"Glass Mat Technology batteries" Before I bought my Odyssey PC-680 from
http://www.Batteries4Everything.com I spent some time digging in my local
area. When I asked for information about RG batteries I got blank looks and
treated like a dolt. Eventually one of the salesman took pity on me and
informed me that the RG reference was "old" and that "GMT" was the new title
for what "old Bob" (;-)! refers to as RG batteries.
The local asking price for the Odyssey PC-680 was $200.00 Canadian. Needless
to say I went shopping on the net. Someone on the List told me to check out
the pricing at Batteries 4 Everything, their price was $62.55 US.
Surprisingly Van's price was much higher at $ 160.00 US!
Happy New Year Walter,
Jim in Kelowna
----- Original Message -----
From: "Walter Casey" <mikec@caseyspm.com>
Subject: AeroElectric-List: Recombinant Gas Batteries
> --> AeroElectric-List message posted by: Walter Casey <mikec@caseyspm.com>
>
> In the literature Bob appears to recommend the RG batteries. The
> problem is that I have searched both B&C and AircraftSpruce but can't
> find the RG batteries.
> Please help.
> Walter
>
>
Message 2
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| Subject: | Re: GPS Antennas |
--> AeroElectric-List message posted by: "Dennis O'Connor" <doconnor@chartermi.net>
Yes, the exterior antenna is a night and day difference... But, the suction
cup antennas that mount on the windshield will probably solve your problem
at lesser cost...
Denny
----- Original Message -----
From: <Whollo80@aol.com>
Subject: AeroElectric-List: GPS Antennas
> --> AeroElectric-List message posted by: Whollo80@aol.com
>
> I'm using a Garmin 90 and sometimes lose coverage on cloudy days. Would
using
> one of the externally mounted antennas improve my coverage? Everything
that I
> see in Aircraft Spruce is a little bit on the expensive side. Any
thoughts?
>
> Bill
>
>
Message 3
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| Subject: | Re: GPS Antennas |
--> AeroElectric-List message posted by: "Dennis O'Connor" <doconnor@chartermi.net>
Bob, I have to take exception to your statement that clouds make no
difference... A thick layer of clouds does absorb energy from the satellite
signals.. If you have a good antenna and therefore a good signal to noise
ratio you will not notice it... But if your receiver s/n ratio is marginal
for what ever reason, a few more dB of loss will make a difference...
Denny
----- Original Message -----
From: <BobsV35B@aol.com>
Subject: Re: AeroElectric-List: GPS Antennas
> --> AeroElectric-List message posted by: BobsV35B@aol.com
>
> In a message dated 12/30/02 7:36:06 PM Central Standard Time,
> Whollo80@aol.com writes:
>
> > I'm using a Garmin 90 and sometimes lose coverage on cloudy days. Would
> > using
> > one of the externally mounted antennas improve my coverage? Everything
that
> > I
> > see in Aircraft Spruce is a little bit on the expensive side. Any
thoughts?
>
> Good Evening Bill,
>
> The clouds should have absolutely nothing to do with your GPS coverage.
> However, getting a full view of the sky is always a good idea. The 90 was
a
> good unit in it's day and still has the capability of providing useful
> information, but the technology curve is still rising quite steeply on
such
> equipment. You might consider upgrading to something like the Garmin 196.
>
> Any remote antenna that will allow a better view of the sky will make the
90
> work a bit better. I don't know whether an active antenna will help with
the
> 90 or not, but why don't you call the Garmin service number? I have found
> them to be easy to get hold of and full of good information.
>
> I added an active antenna for use with my Trimble 2000 Approach Plus.
That
> old antique had it's performance noticeably improved by the addition.
>
> Look up Garmin at: <A HREF="www.garmin.com">www.garmin.com
>
> They have data there as to the phone numbers to call.
>
> Happy Skies,
>
> Old Bob
>
>
Message 4
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| Subject: | cranking amps vs. amp-hours |
--> AeroElectric-List message posted by: "Gary Casey" <glcasey@adelphia.net>
<<If I wire a new 12-volt, 300-cranking amp battery
in series with a new 12-volt, 1000-cranking amp battery,
how many 24-volt cranking amps will be available for use?>>
Just for the fun of it, I will take a crack at this. Don't use the actual
numbers in my explanation as they are just for example: The cranking amps
of a 12-volt battery is rated by taking a fully charged battery and putting
sufficient load on it to drop the voltage to a value of maybe 8 volts. This
has to be sustained for only a short time - 10 seconds perhaps. To measure
the amp-hour capacity the same fully charged battery has a relatively small
load, maybe 2 amps, applied and the battery voltage is measured. When it
drops to some value (10 volts?) the time is measured. Presumably you could
draw 2 amps of current from a 16 amp-hour battery for 8 hours before its
voltage dropped to 10 volts. As you can see, the two ratings quantify two
quite different attributes of a battery. The cranking amps measure how
energetically it will crank the engine and the amp-hour rating will tell you
how long the battery will last after the alternator fails. To optimize a
battery for maximum amp-hours you need lots of lead and lots of acid. To
optimize it for cranking amps you need lots of electrode surface area (like
by making the plates porous, reducing the amount of lead).
What happens when you put the "300-amp" and the "1,000-amp" batteries in
series? Presumably you would rate the cranking amps at 16 volts, given the
numbers above. The capability would be more than 300 amps as the 300 amp
battery could be pulled down below 8 volts, maybe 6 volts, at which time the
more powerful battery would be down to 10 volts. The total amperage would
then be something more than 300 amps, but probably not close to 1,000. I'd
guess 350 or 400. But what about capacity? You didn't say what the
amp-hour rating of each battery was. Presumably the 1,000-amp battery also
had the larger capacity. Certainly, as someone else replied, if you ran the
pair completely dead the smaller capacity battery would eventually be
charged in the reverse direction, but that's not really a horrible
condition.
Bottom line is that while combining two mis-matched batteries in series
isn't such a great idea, the biggest problem is that you aren't getting full
benefit from the larger of the two batteries, whether considering cranking
power in amps or capacity in amp-hours. And the battery life won't be
maximized as one of the batteries will go through more severe
charge/discharge cycles than the other.
Gary Casey
Message 5
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| Subject: | Re: Recombinant Gas Batteries |
--> AeroElectric-List message posted by: Walter Casey <mikec@caseyspm.com>
Thanks Jim,
That was a great help.
Walter :-)
On Monday, December 30, 2002, at 02:33 AM, Jim Jewell wrote:
> --> AeroElectric-List message posted by: "Jim Jewell"
> <jjewell@telus.net>
>
> Hello Walter,
>
> If you have a battery dealer or shop nearby. Go there and enquire about
> "Glass Mat Technology batteries" Before I bought my Odyssey PC-680
> from
> http://www.Batteries4Everything.com I spent some time digging in my
> local
> area. When I asked for information about RG batteries I got blank
> looks and
> treated like a dolt. Eventually one of the salesman took pity on me and
> informed me that the RG reference was "old" and that "GMT" was the new
> title
> for what "old Bob" (;-)! refers to as RG batteries.
> The local asking price for the Odyssey PC-680 was $200.00 Canadian.
> Needless
> to say I went shopping on the net. Someone on the List told me to
> check out
> the pricing at Batteries 4 Everything, their price was $62.55 US.
> Surprisingly Van's price was much higher at $ 160.00 US!
>
> Happy New Year Walter,
>
> Jim in Kelowna
>
> ----- Original Message -----
> From: "Walter Casey" <mikec@caseyspm.com>
> To: <aeroelectric-list@matronics.com>
> Subject: AeroElectric-List: Recombinant Gas Batteries
>
>
>> --> AeroElectric-List message posted by: Walter Casey
>> <mikec@caseyspm.com>
>>
>> In the literature Bob appears to recommend the RG batteries. The
>> problem is that I have searched both B&C and AircraftSpruce but can't
>> find the RG batteries.
>> Please help.
>> Walter
>>
>>
>
>
> _-
> =======================================================================
> _-> _-
> ======================================================================
> _-
> ======================================================================
> _-
> ======================================================================
> _-
> ======================================================================
>
>
Message 6
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| Subject: | Re: cranking amps vs. amp-hours |
--> AeroElectric-List message posted by: John Rourke <jrourke@allied-computer.com>
Gary, good job at establishing the basics - I'll try to build on your
explanation, but I'm just going to focus on "cranking amps" only, since
"amphour capacity" is fairly unrelated (and didn't seem to be part of
the question anyways)...
First, cranking capacity is pretty much a measure of resistance, as I
understand Bob's several essays on the subject... and in one article, he
mentioned that B&C uses 8.5 volts as the desired endpoint voltage for a
"dump test", where the load resistance is lowered until that voltage
level is achieved, and then identifying the current that brought about
that much of a voltage drop... so let's use that, and also assume that
an equivalent 24-volt system would look for double that voltage (17 volts).
The process involves first determining the internal resistances of each
battery - and it is a simple inverse relationship (lower internal
resistance == higher cranking amps), and I'll assume the battery
manufacturer used the same criteria as Bob's "dump test" for their
"cranking-amp" test (and if not it's probably similar). So anyway, if
we're looking for 8.5 volts at the terminal, that would imply a 4.1-volt
drop internally (12.6-8.5), so the internal resistance of the 300-ca
battery would be 4.1/300, or 13.7 milliOms; the 1000-ca battery would
have an internal resistance of 4.1/1000, or 4.1 milliohms. Add the two
together to get 17.8 milliohms total resistance and, assuming you are
looking for a 17-volt level from 25.2 volt potential (8.2 volt drop),
you would see that with about 461 cranking amps (8.2/.0178).
As for a constant drain eventually reverse-charging one of the
batteries, I think that would depend entirely on the reserve amphour
capacity of the battery rather than its cranking amps - and unless you
know that, you can't know which one would outlast the other.
That's how I understand it anyway, if I'm wrong I welcome any correction!
I am curious, though, as to why anyone would do that - perhaps to use a
24-volt starter but 12 volts for everything else? If so, I'd think that
would be an inefficient way to get total battery energy, per unit mass.
I'd think it would usually be better to use two equal batteries,
especially if you're using a yearly replacement schedule for one battery
each year.
-John
Gary Casey wrote:
> --> AeroElectric-List message posted by: "Gary Casey" <glcasey@adelphia.net>
>
> <<If I wire a new 12-volt, 300-cranking amp battery
> in series with a new 12-volt, 1000-cranking amp battery,
> how many 24-volt cranking amps will be available for use?>>
>
> Just for the fun of it, I will take a crack at this. Don't use the actual
> numbers in my explanation as they are just for example: The cranking amps
> of a 12-volt battery is rated by taking a fully charged battery and putting
> sufficient load on it to drop the voltage to a value of maybe 8 volts. This
> has to be sustained for only a short time - 10 seconds perhaps. To measure
> the amp-hour capacity the same fully charged battery has a relatively small
> load, maybe 2 amps, applied and the battery voltage is measured. When it
> drops to some value (10 volts?) the time is measured. Presumably you could
> draw 2 amps of current from a 16 amp-hour battery for 8 hours before its
> voltage dropped to 10 volts. As you can see, the two ratings quantify two
> quite different attributes of a battery. The cranking amps measure how
> energetically it will crank the engine and the amp-hour rating will tell you
> how long the battery will last after the alternator fails. To optimize a
> battery for maximum amp-hours you need lots of lead and lots of acid. To
> optimize it for cranking amps you need lots of electrode surface area (like
> by making the plates porous, reducing the amount of lead).
>
> What happens when you put the "300-amp" and the "1,000-amp" batteries in
> series? Presumably you would rate the cranking amps at 16 volts, given the
> numbers above. The capability would be more than 300 amps as the 300 amp
> battery could be pulled down below 8 volts, maybe 6 volts, at which time the
> more powerful battery would be down to 10 volts. The total amperage would
> then be something more than 300 amps, but probably not close to 1,000. I'd
> guess 350 or 400. But what about capacity? You didn't say what the
> amp-hour rating of each battery was. Presumably the 1,000-amp battery also
> had the larger capacity. Certainly, as someone else replied, if you ran the
> pair completely dead the smaller capacity battery would eventually be
> charged in the reverse direction, but that's not really a horrible
> condition.
>
> Bottom line is that while combining two mis-matched batteries in series
> isn't such a great idea, the biggest problem is that you aren't getting full
> benefit from the larger of the two batteries, whether considering cranking
> power in amps or capacity in amp-hours. And the battery life won't be
> maximized as one of the batteries will go through more severe
> charge/discharge cycles than the other.
>
> Gary Casey
>
>
>
>
>
>
>
>
Message 7
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--> AeroElectric-List message posted by: "Norman and Gretchen Howell" <testwest@earthlink.net>
Sorry, Denny, I think you're the one off base.
GPS uses a psuedorandom noise technique for signal propagation and decoding.
The signal strength is ALREADY below the level of the background noise. That
is why you sometimes hear of the various satellite signals referred to as
"PRN"s. PRN is a neat way to make a weak signal difficult to jam.
The only reason "clouds" may affect the performance is "maybe" some static
buildup on the airframe. Personally, I would do some more investigating of
the problem report rather than continue talking about clouds and GPS.
Bill, contact me off list if you would. Let's see what we can deduce from a
more detailed examination of your squawk.
Norm Howell
Experimental Test Pilot
Boeing (formerly Douglas), Long Beach
building: Berkut 540, dual EI, fig Z-13
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Dennis
O'Connor
Subject: Re: AeroElectric-List: GPS Antennas
--> AeroElectric-List message posted by: "Dennis O'Connor"
<doconnor@chartermi.net>
Bob, I have to take exception to your statement that clouds make no
difference... A thick layer of clouds does absorb energy from the satellite
signals.. If you have a good antenna and therefore a good signal to noise
ratio you will not notice it... But if your receiver s/n ratio is marginal
for what ever reason, a few more dB of loss will make a difference...
Denny
----- Original Message -----
From: <BobsV35B@aol.com>
Subject: Re: AeroElectric-List: GPS Antennas
Message 8
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--> AeroElectric-List message posted by: "Rhett Westerman" <Rhettwesterman@cox.net>
Bob and Bob,
I had the exact same problem and could not get it resolved. I finally
replaced the OVM and all is well now.
best,
Rhett
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert
Kellar
Subject: AeroElectric-List: OV regulatro
--> AeroElectric-List message posted by: "Robert Kellar" <rkellar@attbi.com>
Thank you for you quick response. I missed the part about the breaker in
the instructions. I'll install a breaker and fly some more and then let you
know here on the list. Re: Voltage before the fuse blows...I am too busy
flying the takeoff to notice. I'll bring a passenger to monitor this value.
Bob Kellar
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: 10179 Kellar
> At 10:51 PM 12/29/2002 -0800, you wrote:
> >Below is the result of your inquiry. It was submitted by
> >Robert Kellar (rkellar@attbi.com) on Sunday, December 29, 2002 at
22:51:40
>
> >
> >Sunday, December 29, 2002
> >
> >Robert Kellar
> >
> >,
> >Email: rkellar@attbi.com
> >Comments/Questions: I am using your voltage regulator LR3B-14 in my
> >RV6. Purchased 2 years ago. Worked wonderfully until 2 months ago. On
> >multiple occasions the 5A fuse from the bus to the master switch to
> >terminal 6 blows.
>
> This fuse should have been a circuit breaker . . . all of our
> installation drawings show a breaker used with any form of
> crowbar overvoltage protection.
>
> > When not blown the voltage regulator functions perfectly 20+ amps
> > charge then cycles down to less than 5 amps for flight. Usually the
fuse
> > lasts for 1 hr or less and then with the next flight, as I take off the
> > fuse will blow and the blinking warning light comes on. Replace the
fuse
> > and I can fly again for awhile. I have inspected everything in the
panel,
> > wires, connections etc looking for a possible short or failure. My
> > question is...Is there anything internal to the unit that could cause
> > this intermittent failure? If not, I will continue my investigation of
> > all the wire out to the alternator looking for a possible intermittent
short.
>
> Do you have a voltmeter in the airplane? What does it read
> just before the ov system trips?
>
> > Thank you for your response and all the help provided on the net and
in
> > your electical manual and diagrams.
>
> My pleasure sir.
>
> I will invite you to join us on the AeroElectric List
> to continue this and similar discussions. It's useful to
> share the information with as many folks as possible.
> You can join at . . .
>
> http://www.matronics.com/subscribe/
>
> Thanks!
>
> Bob . . .
>
> |---------------------------------------------------|
> | A lie can travel half way around the world while |
> | the truth is till putting on its shoes . . . |
> | -Mark Twain- |
> |---------------------------------------------------|
>
Message 9
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| Subject: | Re: cranking amps vs. amp-hours |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:24 AM 12/31/2002 -0600, you wrote:
>--> AeroElectric-List message posted by: John Rourke
><jrourke@allied-computer.com>
>
>Gary, good job at establishing the basics - I'll try to build on your
>explanation, but I'm just going to focus on "cranking amps" only, since
>"amphour capacity" is fairly unrelated (and didn't seem to be part of
>the question anyways)...
. . . correct. I've seen 1.2 a.h. cells that would dump
over 1000 amps. Unfortunately, they were so difficult to
build that the process never made it to the marketplace.
>First, cranking capacity is pretty much a measure of resistance, as I
>understand Bob's several essays on the subject... and in one article, he
>mentioned that B&C uses 8.5 volts as the desired endpoint voltage for a
>"dump test", where the load resistance is lowered until that voltage
>level is achieved, and then identifying the current that brought about
>that much of a voltage drop... so let's use that, and also assume that
>an equivalent 24-volt system would look for double that voltage (17 volts).
>
>The process involves first determining the internal resistances of each
>battery - and it is a simple inverse relationship (lower internal
>resistance == higher cranking amps), and I'll assume the battery
>manufacturer used the same criteria as Bob's "dump test" for their
>"cranking-amp" test (and if not it's probably similar). So anyway, if
>we're looking for 8.5 volts at the terminal, that would imply a 4.1-volt
>drop internally (12.6-8.5), so the internal resistance of the 300-ca
>battery would be 4.1/300, or 13.7 milliOms; the 1000-ca battery would
>have an internal resistance of 4.1/1000, or 4.1 milliohms. Add the two
>together to get 17.8 milliohms total resistance and, assuming you are
>looking for a 17-volt level from 25.2 volt potential (8.2 volt drop),
>you would see that with about 461 cranking amps (8.2/.0178).
. . . I believe this analysis is correct.
>As for a constant drain eventually reverse-charging one of the
>batteries, I think that would depend entirely on the reserve amphour
>capacity of the battery rather than its cranking amps - and unless you
>know that, you can't know which one would outlast the other.
True . . . but unless the 1000CA battery is one of those
itty-bitty cells I cited above, it's a fair bet that the
battery with the larger cranking current rating is also
the larger battery with respect to capacity . . . so
in a series connected deep discharge of the pair of
batteries, the smaller one would be at risk for reverse
charge damage.
>That's how I understand it anyway, if I'm wrong I welcome any correction!
>
>I am curious, though, as to why anyone would do that - perhaps to use a
>24-volt starter but 12 volts for everything else? If so, I'd think that
>would be an inefficient way to get total battery energy, per unit mass.
>I'd think it would usually be better to use two equal batteries,
>especially if you're using a yearly replacement schedule for one battery
>each year.
I was curious about this configuration too. I have used
pairs of identical batteries in series to get 48V for
cranking and then paralleled them for operation as
a 28v system for flight operations. Unless there is
some compelling reason to carry the 1000CA battery,
a pair of 17 a.h. RG batteries would yield 300-400
amps for cranking and 34 a.h. capacity for flight
operations . . . a rather robust combination for about
any airplane.
Bob . . .
Message 10
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| Subject: | Re: AeroElectric-List Digest: 26 Msgs - 12/30/02 |
--> AeroElectric-List message posted by: Mitch Williams <mitchw62@prodigy.net>
Bill,
I've had a gps-90 for about 5 years. It would lose
satellites from time to time and sometimes take
forever to find itself again.
about 3 years ago, I installed an externally mounted
active antenna from GPSwolf for about $60 - included
with a radio upgrade on a 337. I went from 3-4
satellites receiving, to all 8, all the time. It
works much better but didn't solve all problems. IT
STILL GET LOST, and TAKE FOREVER TO FIND ITSELF.
I was giving rides over the Christmas lights last week
and didn't turn on the gps90 - didn't need it. Decide
to turn it on during the trip. It could only find 2
sats, then 3 sats, then none - I looked over the
cables, unplugged, repluges, power-off power-on, no
difference - yea it was cloudy - Who knows? Still no
sats. Next day, all eight working fine - well it took
10 minutes to find them.
I used a 195 on a 5 hour trip a couple months ago. It
found all 12 in seconds and never missed a beat.
As Bob said, the 90 is getting long in the tooth. A
better investment be a newer 12 sat parallel unit in
place of the 8 sat serial.
Mitch N7155A
> --> AeroElectric-List message posted by:
> Whollo80@aol.com
>
> I'm using a Garmin 90 and sometimes lose coverage on
> cloudy days. Would using
> one of the externally mounted antennas improve my
> coverage? Everything that I
> see in Aircraft Spruce is a little bit on the
> expensive side. Any thoughts?
>
> Bill
>
>
Message 11
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| Subject: | Re: cockpit backup batteries |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>Bob,
>I want to rig a lead from my 300 amp starter boster,
>(with 12v dc outlet) to my instrument panel cigar
>lighter that can be used to power the bus in the event
>of an electrical failure. my aircraft is a 62 mooney
>m20c with a 14v system with an overhauled delco remy
>50 amp generator.
Have you ever considered a field approval for a
B&C L-60? It offers about 10x the reliability of that
generator and should run the lifetime of the airplane.
> . . my concern is that if i take two cigarette lighter
>adapters, snip off the ends and wire them together, the
>wiring will not be able to handle the load required to power
>the buss, which i would estimate to be 20-30 amps with
>pitot heat on.
A max endurance IFR load (w/pitot heat) of less
than 15A should be possible. This is still pushing
a cigar lighter connector . . . ESPECIALLY two of
these things in series. They were originally designed
to work in a situation where high energy losses were
EXPECTED . . . i.e., heat up the little coil of
heater wire in a lighter . . . several decades of
attempts to improve on the electrical integrity
of these connectors haven't accomplished much.
I cannot recommend that anyone configure a system
that might DEPEND on these connectors as part
of a system intended to back up the primary
power source. I personally don't use them
in any situation loaded to more than 10A
(small inverters used run computers and
test equipment in vehicles).
You mentioned a 300 amp rating on the booster
battery. These are generally fitted with 17 a.h.
RG batteries. ALL of the commercial, off the
shelf, booster products I've disassembled for
inspection use the very cheapest batteries
on the market. While they are indeed an RG product,
I would be hesitant to suggest they might be
a dependable back up power source. If my
airplane needed a 17 a.h. battery to get home
I'd have no problems going to Sams or WalMart
to scavenge the battery out of a portable
power product to get me home, but I wouldn't
leave that battery in service very long.
Backup batteries as a cockpit accessory have
been offered for years (saw one during my first
trip to OSH in '86). It seems like a good idea
but only because it interfaces with the airplane
in ways that keep those-who-think-they-know-more-
about-airplanes-than-us at arm's length. The
siren song of a certification-free solution
is compelling . . . but if you found yourself
truly in need of this device on some flight,
the LAST things you need to be fiddling with
are (1) twisting crappy connectors around in their
sockets in an attempt to improve connections,
(2) trying to maximize endurance with load-
reduction decisions and (3) being disappointed
when the battery inside the low-dollar, shade-
tree mechanic's product turns out to have less
capability than you would have supposed.
If I owned your airplane I would first
ditch the generator for ANY alternator . . .
but a B&C L-60 would be the first choice.
Put a new battery in every year -OR- do
capacity checks to insure that I had a
SUBSTANTIAL endurance capability sans
alternator . . . for my OBAM airplane
friends, this means for duration of fuel
aboard. You probably can't get that much
time but it's a certainty that with
considered planning for battery maintenance
and load reduction, you can get a whole lot
more from the standard ship's battery than
you'll ever get from a 20-pound lead missile
setting on the floor of the cockpit.
A third feature I'd work for is to convert
the avionics bus into an endurance bus
and provide it with normal and alternate
feed paths as described in Chapter 17
of the 'Connection which you can download
at:
http://www.aeroelectric.com/articles/Rev9/ch17-9.pdf
This modification would require moving
a few things not generally considered
"avionics" to the new endurance bus.
>any suggestions regarding how to wire this lead
>and what to use would be appreciated. happy new year....
Accomplish these things my friend and I am
certain you'll end up with a simpler, lighter,
easier to maintain and certainly more reliable
system than a basket full of cigar-lighter
connected batteries will ever offer.
Bob . . .
Message 12
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| Subject: | Re: AeroElectric-List Digest: 26 Msgs - 12/30/02 |
--> AeroElectric-List message posted by: "Dennis O'Connor" <doconnor@chartermi.net>
I have a 195 and a 196 in the plane... Both are reliable... The 196 is much
faster to boot up and locate itself...
Denny
----- Original Message -----
From: "Mitch Williams" <mitchw62@Prodigy.net>
Subject: AeroElectric-List: Re: AeroElectric-List Digest: 26 Msgs - 12/30/02
> --> AeroElectric-List message posted by: Mitch Williams
<mitchw62@prodigy.net>
>
> Bill,
> I've had a gps-90 for about 5 years. It would lose
> satellites from time to time and sometimes take
> forever to find itself again.
> about 3 years ago, I installed an externally mounted
> active antenna from GPSwolf for about $60 - included
> with a radio upgrade on a 337. I went from 3-4
> satellites receiving, to all 8, all the time. It
> works much better but didn't solve all problems. IT
> STILL GET LOST, and TAKE FOREVER TO FIND ITSELF.
>
> I was giving rides over the Christmas lights last week
> and didn't turn on the gps90 - didn't need it. Decide
> to turn it on during the trip. It could only find 2
> sats, then 3 sats, then none - I looked over the
> cables, unplugged, repluges, power-off power-on, no
> difference - yea it was cloudy - Who knows? Still no
> sats. Next day, all eight working fine - well it took
> 10 minutes to find them.
>
> I used a 195 on a 5 hour trip a couple months ago. It
> found all 12 in seconds and never missed a beat.
>
> As Bob said, the 90 is getting long in the tooth. A
> better investment be a newer 12 sat parallel unit in
> place of the 8 sat serial.
>
> Mitch N7155A
>
>
> > --> AeroElectric-List message posted by:
> > Whollo80@aol.com
> >
> > I'm using a Garmin 90 and sometimes lose coverage on
> > cloudy days. Would using
> > one of the externally mounted antennas improve my
> > coverage? Everything that I
> > see in Aircraft Spruce is a little bit on the
> > expensive side. Any thoughts?
> >
> > Bill
> >
> >
>
>
Message 13
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| Subject: | Re: GPS Antennas |
--> AeroElectric-List message posted by: "Dennis O'Connor" <doconnor@chartermi.net>
Oh gee Norm, it's so nice to be dismissed... Since the signal is below the
noise level already another 20dB of loss ratio means nothing, I guess you
will have no problem recovering a C/No 33 dB-Hz from a now -172dBm
signal....
Denny
----- Original Message -----
From: "Norman and Gretchen Howell" <testwest@earthlink.net>
Subject: RE: AeroElectric-List: GPS Antennas
> --> AeroElectric-List message posted by: "Norman and Gretchen Howell"
<testwest@earthlink.net>
>
> Sorry, Denny, I think you're the one off base.
>
> GPS uses a psuedorandom noise technique for signal propagation and
decoding.
> The signal strength is ALREADY below the level of the background noise.
That
> is why you sometimes hear of the various satellite signals referred to as
> "PRN"s. PRN is a neat way to make a weak signal difficult to jam.
>
> The only reason "clouds" may affect the performance is "maybe" some static
> buildup on the airframe. Personally, I would do some more investigating of
> the problem report rather than continue talking about clouds and GPS.
>
> Bill, contact me off list if you would. Let's see what we can deduce from
a
> more detailed examination of your squawk.
>
> Norm Howell
> Experimental Test Pilot
> Boeing (formerly Douglas), Long Beach
> building: Berkut 540, dual EI, fig Z-13
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Dennis
> O'Connor
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: GPS Antennas
>
>
> --> AeroElectric-List message posted by: "Dennis O'Connor"
> <doconnor@chartermi.net>
>
> Bob, I have to take exception to your statement that clouds make no
> difference... A thick layer of clouds does absorb energy from the
satellite
> signals.. If you have a good antenna and therefore a good signal to noise
> ratio you will not notice it... But if your receiver s/n ratio is marginal
> for what ever reason, a few more dB of loss will make a difference...
>
> Denny
> ----- Original Message -----
> From: <BobsV35B@aol.com>
> To: <aeroelectric-list@matronics.com>
> Subject: Re: AeroElectric-List: GPS Antennas
>
>
Message 14
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| Subject: | Re: Recombinant Gas Batteries |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 12:05 AM 12/31/2002 -0700, you wrote:
>--> AeroElectric-List message posted by: Walter Casey <mikec@caseyspm.com>
>
>In the literature Bob appears to recommend the RG batteries. The
>problem is that I have searched both B&C and AircraftSpruce but can't
>find the RG batteries.
>Please help.
>Walter
"Recombinant Gas" (RG) is also "Starved Electrolyte" is also
"Glass-Mat-Technology", is also "Vented Sealed Lead Acid" (VLSA),
and sometimes called "Maintenance Free" but can become confused
with flooded batteries having glued on caps to make them
"Maintenance Difficult" . . . they are oft referred to in
error as "Gel-Cell" batteries in honor of the first series of
"Immobilized Electrolyte" batteries of some 40 odd years ago.
By and large, ANY lead-acid battery offered today other than
flooded batteries for use in vehicles will be the more
modern technology product irrespective of what name the
sales person recognizes.
See the following sites for a tip-of-the-iceberg view
of available products and some additional information
on battery technologies.
http://www.hepi.com/
http://www.concordebattery.com/
http://www.panasonic.com/industrial/battery/oem/chem/seal/index.html
http://www.mywebplace.com/yuasaspec.html
http://www.sbw.org/batcap/
http://www.batteryweb.com/optima.cfm
http://www.batteryweb.com/powersonic12vsla.cfm
http://www.4unique.com/battery/battery_tutorial.htm
http://www.4unique.com/battery/batteries.htm
If your heart is really set on a "gel-cell" battery, you
can get 'em here:
http://www.batteryweb.com/sonnenschein.cfm
. . . and to top it off my friends, here's a seller
that delivers much elephant-hocky about products
he doesn't even know the proper name for much less
understand how they work.
http://www.emesystems.com/batcharg.htm
Happy new year.
Bob . . .
Message 15
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| Subject: | Re: GPS Antennas |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 08:12 AM 12/31/2002 -0500, you wrote:
>--> AeroElectric-List message posted by: "Dennis O'Connor"
><doconnor@chartermi.net>
>
>Yes, the exterior antenna is a night and day difference... But, the suction
>cup antennas that mount on the windshield will probably solve your problem
>at lesser cost...
Active GPS antennas don't have to be expensive. I've used
a number of products from these folks and plans to use
quite a few more. Check out these $19 active antennas
http://www.laipac.com/products/gps/GPS%20Active%20Antennas.htm
Bob . . .
Message 16
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| Subject: | Re: GPS receivers |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:32 AM 12/31/2002 -0800, you wrote:
>--> AeroElectric-List message posted by: Mitch Williams <mitchw62@prodigy.net>
>
>Bill,
>I've had a gps-90 for about 5 years. It would lose
>satellites from time to time and sometimes take
>forever to find itself again.
>about 3 years ago, I installed an externally mounted
>active antenna from GPSwolf for about $60 - included
>with a radio upgrade on a 337. I went from 3-4
>satellites receiving, to all 8, all the time. It
>works much better but didn't solve all problems. IT
>STILL GET LOST, and TAKE FOREVER TO FIND ITSELF.
>
>I was giving rides over the Christmas lights last week
>and didn't turn on the gps90 - didn't need it. Decide
>to turn it on during the trip. It could only find 2
>sats, then 3 sats, then none - I looked over the
>cables, unplugged, repluges, power-off power-on, no
>difference - yea it was cloudy - Who knows? Still no
>sats. Next day, all eight working fine - well it took
>10 minutes to find them.
>
>I used a 195 on a 5 hour trip a couple months ago. It
>found all 12 in seconds and never missed a beat.
>
>As Bob said, the 90 is getting long in the tooth. A
>better investment be a newer 12 sat parallel unit in
>place of the 8 sat serial.
I've been using Magellan hand helds in the cockpit
for years. I prop them up on the glare-shield with
a velcro foot hold and a dab of windshield sealant
between the back of the antenna and the plexiglas.
The oldest receiver (2000) is about 5 years old
and it will loose lock in a high-g, 90 degree
turn but recover in a few seconds. The later
models (300/310/315) don't suffer from this
effect. ALL receivers take much more time to
figure out where we are if (1) they are turned
on some distance from where they were turned off
and (2) we're now moving over the ground at
more than 100 kts. This is why I put fresh
batteries in both receivers, plunk them down
on the glare-shield and turn them on during
pre-flight.
Once they figure out where we are, they've
performed very well for gizmos that cost about
$100 each. Just as an experiment, I've left
one shut off and then turned it on after 200 miles
of travel and while still airborne. The 2000
never did get locked on for the remainder
of the flight (about 10 minutes) . . . but
figured it all out while on taxi to the ramp.
The 300 series devices took about 5 minutes
but did eventually sort out all the puzzle
pieces. I plan to cold-initialize one of these
guys in flight some day and see how it does.
Bob . . .
>Mitch N7155A
>
>
> > --> AeroElectric-List message posted by:
> > Whollo80@aol.com
> >
> > I'm using a Garmin 90 and sometimes lose coverage on
> > cloudy days. Would using
> > one of the externally mounted antennas improve my
> > coverage? Everything that I
> > see in Aircraft Spruce is a little bit on the
> > expensive side. Any thoughts?
> >
> > Bill
> >
> >
>
>
Bob . . .
|-------------------------------------------------------|
| The man who does not read good books has no advantage |
| over the man who cannot read them. |
| - Mark Twain |
|-------------------------------------------------------|
Message 17
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| Subject: | RE: OV protection |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:24 AM 12/31/2002 -0600, you wrote:
>--> AeroElectric-List message posted by: "Rhett Westerman"
><Rhettwesterman@cox.net>
>
>Bob and Bob,
>
> I had the exact same problem and could not get it resolved. I finally
>replaced the OVM and all is well now.
>
>best,
>
>Rhett
Was your OVM one that I had upgraded? Do you still have the
old one?
The case under discussion is for an LR3 regulator with
built-in OV protection. Slightly different circuit but
with similar potential for nuisance trips under certain
conditions. We modified the design on these also about
18 months ago.
I'm curious in this instance as to why a unit that
performed well for several years showed a new problem.
We need to be sure it's not responding to a true higher
than normal bus voltage condition before we offer to take
his unit back for modification.
Thousands of these regulators and OV modules have
been in service for over 10 years and in a very small
number of cases, have we seen the nuisance tripping
condition. Sometimes it's related to system architecture.
Troubles on a new installation in Bonanzas first brought
the problem to light . . . EVERY airplane would do it.
In the case under discussion, I'm curious as to what
changed to make a successful application go sour after
several years of service.
Bob . . .
Message 18
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| Subject: | second alternator |
--> AeroElectric-List message posted by: Paul Wilson <pwilson@climber.org>
Lots of discussion on alternators over the years. I would like to
get help for my 912 Kitfox. For 10 to 12 amps slightly less than the
Rotax, the L40/SD20 and SD8/200G seen on the B&C web page. The vacuum
drive while being handy is expensive due to the modifications
required for the Rotax to get the gears installed. So I am looking at
two alternators and adding a belt drive unit.
I probably can modify the Accessory drive B&C alternators to add a
pulley and mounting provisions. The PM units are slightly smaller and
lighter (2.9 vs 5.7 pounds).
Question: Is the SD8 an acceptable alternative to the SD20? The cost
is less for the SD8 and it uses a less expensive regulator. I wonder
what I would give up with the SD8.
What is the heritage of the SD8?
Thanks, Paul
PS, The alternators are described at:
http://www.bandcspecialty.com/cgi-bin/ez-catalog/cat_display.cgi?2X358218
Message 19
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| Subject: | RE: OV protection |
--> AeroElectric-List message posted by: "Rhett Westerman" <Rhettwesterman@cox.net>
Bob,
I had the OVM module installed and put 644 hours on it in three years. Put
it in service in 98 but purchased the OVM probably in 97. Early on it
tripped a few times but then quit tripping and performed well for about 600
hours. Then the plane sat for a year and I put a new engine and alternator
in the plane. Same regulator etc.
The tripping started immediately. I swapped regulators and alternators with
no change. Still got the tripping. Checked wiring etc and still no
resolution. Last thing to change was the module itself. That did the job.
Also note went back to the original alternator I got with the new engine and
the same regulator that I have now had for many years. This was in Nov and
now 50 hours later not one trip.
I just assumed the OVM went bad. BTW, I have the vision system that records
min and max voltages and the voltage was not going above 14.6 when the
tripping was occurring, so there was never a voltage spike unless it was too
fast for the Vision to capture.
best,
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert
L. Nuckolls, III
Subject: AeroElectric-List: RE: OV protection
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
At 10:24 AM 12/31/2002 -0600, you wrote:
>--> AeroElectric-List message posted by: "Rhett Westerman"
><Rhettwesterman@cox.net>
>
>Bob and Bob,
>
> I had the exact same problem and could not get it resolved. I finally
>replaced the OVM and all is well now.
>
>best,
>
>Rhett
Was your OVM one that I had upgraded? Do you still have the
old one?
The case under discussion is for an LR3 regulator with
built-in OV protection. Slightly different circuit but
with similar potential for nuisance trips under certain
conditions. We modified the design on these also about
18 months ago.
I'm curious in this instance as to why a unit that
performed well for several years showed a new problem.
We need to be sure it's not responding to a true higher
than normal bus voltage condition before we offer to take
his unit back for modification.
Thousands of these regulators and OV modules have
been in service for over 10 years and in a very small
number of cases, have we seen the nuisance tripping
condition. Sometimes it's related to system architecture.
Troubles on a new installation in Bonanzas first brought
the problem to light . . . EVERY airplane would do it.
In the case under discussion, I'm curious as to what
changed to make a successful application go sour after
several years of service.
Bob . . .
Message 20
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--> AeroElectric-List message posted by: "Norman and Gretchen Howell" <testwest@earthlink.net>
Hi everyone
Hope the message below does not offend anyone. I probably could have couched
my previous reply to Denny a bit more diplomatically.
Here is an interesting link for those into GPS signal detection:
http://esl.eng.ohio-state.edu/~swe/argus/argus1.pdf
The interesting point to the present discussion is the signal to noise ratio
that a normal GPS code is dug out of the background noise is -34dB or 4 x
10**-4. Or, the background noise is 2500 times as stong as the GPS signal.
Don't think clouds are gonna attenuate such a weak signal to make much of a
difference anyway.
The point is, we have someone who has a perceived problem with their GPS
receiver. As I said before, the best solution is to better quantify the
problem and deduce the root cause using our noggins instead of our emotions.
It is HIGHLY unlikely clouds have anything to do with Bill's problem of loss
of coverage.
A friend of mine, Terry Schubert, had problems with his GPS 90 that turned
out to be a defective antenna. There could be other issues as well, such as
trying to "cold start" a GPS (i.e. download an almanac and self-initialize
present position, time and date) while it is in motion.
I have found most folks truly do not understand how their magic GPS's work.
Trimble used to have a neat book that explained the system in
easy-to-understand language. I believe it was called "The 9th Utility"....
Norm Howell
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Dennis
O'Connor
Subject: Re: AeroElectric-List: GPS Antennas
--> AeroElectric-List message posted by: "Dennis O'Connor"
<doconnor@chartermi.net>
Oh gee Norm, it's so nice to be dismissed... Since the signal is below the
noise level already another 20dB of loss ratio means nothing, I guess you
will have no problem recovering a C/No 33 dB-Hz from a now -172dBm
signal....
Denny
----- Original Message -----
From: "Norman and Gretchen Howell" <testwest@earthlink.net>
Subject: RE: AeroElectric-List: GPS Antennas
> --> AeroElectric-List message posted by: "Norman and Gretchen Howell"
<testwest@earthlink.net>
>
> Sorry, Denny, I think you're the one off base.
>
> GPS uses a psuedorandom noise technique for signal propagation and
decoding.
> The signal strength is ALREADY below the level of the background noise.
That
> is why you sometimes hear of the various satellite signals referred to as
> "PRN"s. PRN is a neat way to make a weak signal difficult to jam.
>
> The only reason "clouds" may affect the performance is "maybe" some static
> buildup on the airframe. Personally, I would do some more investigating of
> the problem report rather than continue talking about clouds and GPS.
>
> Bill, contact me off list if you would. Let's see what we can deduce from
a
> more detailed examination of your squawk.
>
> Norm Howell
> Experimental Test Pilot
> Boeing (formerly Douglas), Long Beach
> building: Berkut 540, dual EI, fig Z-13
<snip>
Message 21
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| Subject: | Re: citabria triping overvoltage relay |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 11:07 AM 12/21/2002 -0600, you wrote:
>--> AeroElectric-List message posted by: "Stephen Johnson"
><spjohnsn@ix.netcom.com>
>
>A good thing to do would be to get a portable oscilloscope and take a look
>at the battery voltage to see how clean it is. A bad alternator with some
>diodes blown will cause ripple in the voltage which can trip the overvoltage
>relay.
>
>Steve Johnson
>building RV-8
Damaged alternators should not be a source of nuisance trips
in the ov protection system. The period of the ripple frequency
from an alternator is on the order of .5 to 5 milliseconds. The
time constant of a 14V ov module for a step function from 14 to
20 volts should be on the order of 50-100 milliseconds.
While an open diode may cause a working regulator to increase
field current to compensate for the reduced alternator output,
it's doubtful that waveform peaks will be of sufficient
magnitude and duration to trip off the ov protection. Diode
failure could be the last straw in a series of conditions
like ov trip point drifted down, regulator setpoint drifted
up -AND- the alternator lost a diode . . . but that's stacking
multiple problems up pretty deep . . .
Bob . . .
Message 22
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| Subject: | Alternator weights |
--> AeroElectric-List message posted by: Charles Brame <charleyb@earthlink.net>
Interested in either the B&C L-60 or L-40 alternator. The L-60 may be
overkill, but might be nice if its size and weight are close to the
L-40. I cannot find any reference to weight on the B& C sites.
Does anyone know what the L-60 and the L-40 alternators weigh.
Charlie Brame
RV-6A N11CB
San Antonio
Message 23
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| Subject: | Re: Alternator weights |
--> AeroElectric-List message posted by: Walter Casey <mikec@caseyspm.com>
Hi Charlie,
I called them with that very question today and told them that the data
should be on their web site. They agreed.
As I recall the L-60 is 8.5 lbs and the L-40 is 6 lbs.
Best wishes,
Walter
On Tuesday, December 31, 2002, at 04:23 PM, Charles Brame wrote:
> --> AeroElectric-List message posted by: Charles Brame
> <charleyb@earthlink.net>
>
> Interested in either the B&C L-60 or L-40 alternator. The L-60 may be
> overkill, but might be nice if its size and weight are close to the
> L-40. I cannot find any reference to weight on the B& C sites.
>
> Does anyone know what the L-60 and the L-40 alternators weigh.
>
> Charlie Brame
> RV-6A N11CB
> San Antonio
>
>
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