Today's Message Index:
----------------------
1. 06:13 AM - Re: what is the truth about gps antennas? (FLYaDIVE)
2. 06:33 AM - Re: what is the truth about gps antennas? (Alec Myers)
3. 07:34 AM - Re: what is the truth about gps antennas? (Alec Myers)
4. 08:14 AM - Re: what is the truth about gps antennas? (FLYaDIVE)
5. 08:57 AM - Re: what is the truth about gps antennas? (Lyn Robertson)
6. 09:07 AM - Z-14 Switches Preferred... (Bill Simpson)
7. 10:01 AM - Re: what is the truth about gps antennas? (FLYaDIVE)
8. 11:01 AM - Re: Z-14 Switches Preferred... (Charlie England)
9. 11:44 AM - Re: what is the truth about gps antennas? (Alec Myers)
10. 02:22 PM - Re: Z-14 Switches Preferred... (C&K)
11. 06:45 PM - Re: Z-14 Switches Preferred... (Robert L. Nuckolls, III)
12. 07:48 PM - Re: what is the truth about gps antennas? (Ernest Christley)
13. 08:19 PM - Re: what is the truth about gps antennas? (FLYaDIVE)
Message 1
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Subject: | Re: what is the truth about gps antennas? |
Alec:
I did say "Rule of Thumb". I did not look up if the dB gain expressed in
the manual is voltage or power, but I'm pretty sure it would be voltage.
And the rule of thumb is the voltage signal will double with every 3 dB of
gain. Ya got me... I did not sit down with my slide rule and work out the
voltage gain, I am just trying to show a relative number that non
engineers can work with.
But, your numbers are incorrect. A 10,000:1 dB ratio gain would be more
like 80 dB's not 40 dB's.
See: *Common Gains and Losses Expressed in Decibels*
http://www.sengpielaudio.com/calculator-FactorRatioLevelDecibel.htm
Barry
On Sat, Dec 22, 2018 at 11:31 PM Alec Myers <alec@alecmyers.com> wrote:
> 40dB is 40/3 = 13.3 doublings, or a ratio of 2^13.3, which is about
> 10,000, as you say.
>
> On Dec 22, 2018, at 21:10, Henador Titzoff <henador_titzoff@yahoo.com>
> wrote:
>
> It's an old wive's tale that a 40 dB gain is 40/3 = 13 times power gain
> over 0 dB.
>
> The decibel is a ratio of two physical properties expressed mathematicall
y
> using logarithmic base 10. When referring to power, below are the
> calculated values using the equation dB = 10xLog10(P/Po):
>
> 0 dB = 1
> 3 dB = 1.995 = ~2
> 6 dB = 3.981 = ~4
> 9 dB = 7.95 = ~8
> 10 dB = 10.0
> 20 dB = 100.0
> 30 dB = 1000.0
> 40 dB = 10,000.0
>
> So 40 DB represents a ratio of 10,000, not 13. If 0 dB = 1 milliWatt,
> then 40 dB = 10 Watts.
>
> Everything else you say below is correct except that RF engineers, as wel
l
> as LiDAR engineers, refer to too much signal as saturation, not splatter.
> Maybe I'm hanging out with a different bunch of engineers, but we use wha
t
> the literature says.
>
> Henador Titzoff
>
>
> On Saturday, December 22, 2018, 8:03:24 PM EST, FLYaDIVE <
> flyadive@gmail.com> wrote:
>
>
> Hi Kevin:
>
>
> You are 300% right to question Old Wive's Tails.
> The Paint Story is not without some merit. It stems from the idea of how
> the Color was produced. Black and Gray for example could come from a
> CARBON. Carbon is conductive, not highly so but conductive. After all
> Carbon Resistors are exactly that Carbon and Conductive.
> The old Green, Copper and Bronze have Copper and Bronze metals in them.
> White paint can have Titanium Dioxide in it and titanium is metal and
> slightly conductive.
> There are also paints such as primers which have Zinc in them.
> Well, you can see the thought process, that conductive paints can cause
> some problems.
> So, why take the chance... The industry makes a general Old Wive's Tail
> statement of Do Not Paint GPS Antennas.
> Of course the Pigment of paints have changed over the years, too bad the
> Old Wive's Tails have a stronger following than the process of common
> sense.
> What YOU can do is read the Ingredients List of what makes the paint the
> color (Pigment) and see if any of the above items are listed. ALSO, you
> can look up the MSDS for the paint.
>
> Next: -
> OVER DRIVEN: - We should be so lucky.
> YES! There is such a thing. It is also know in Receiver Theory as Front
> End Over Load.
> Too much signal is received and causes SPLATTER - Too much signal coverin
g
> too wide a bandwidth.
> The 'Active" GPS Antennas do have amplifiers built into them. They
> usually range between 10 to 40 dB Gain.
> The rule of dB is every 3 dB doubles your signal. So, YES, in theory if
> you have a 40 dB gain antenna you could have 40/3 = 13 times the
> un-amplified signal. That could be too much for the receiver to handle.
> Of course there is a loss in the coax, loss in each of the connectors and
> an additional loss in the 90 Deg connector.
> So, if an engineer sits down with the slide-ruler the NUMBERS would say
> YES, there is too much signal coming down the RG-400. SO! Why not be
> smarter than the Engineer - Save your Money - Buy RG-58/AU and run the
> shortest length possible? Buy It - HELL! I have a 150 foot spool! But
> NOooooo.... Common Sense is over ruled by Sales Pitch and owners spend
> $4.00 per foot for RG-400 and they buy 10 foot when only 3 foot is need f
or
> the run. 10 Foot @ $4 = $40 Vs 3 Foot @ $0.75 = $2.25.
> So Kevin, you did VERY - VERY GOOD!
>
> Guess What! I did the EXACT same thing with the Stratus ESG coax
> situation as you. I also mounted it on my Glare Shield. But, I have a
> carper over the antenna so I did not have to paint the antenna.
>
> Works Great, Works Fine - FM!
>
> Barry
>
>
> message posted by: "kjlpdx" <kevinlane55@gmail.com>
>
>
> I'm interested in hearing from an engineer who might know about what
> really goes on with my stratus esg gps antenna. they say to use RG400
> cable, 10' minimum, and never paint the antenna. they also told me the
> strength ratings should run in the 30's. I have 3' of RG400 with a
> mechanical 90=C3=82=C2=B0 elbow, I spray painted the antenna flat black a
nd mounted
> it on the glareshield of my RV. my readings are all in the 40's. they tol
d
> me this shows an overdriven condition.
> so why use low impedance cable then need 10'? my iFly740 and Lowrance 100
0
> gps's have antennas with much smaller cables. the iFly shows WAAS grade
> accuracy, using an antenna 1/4 the size of the stratus RAMI antenna.
> when does being overdriven prove to be a problem? is this a situation
> where I could add more mechanical connectors to increase impedance rather
> than more cable length?
> I get the feeling things get written and then forever repeated, such as
> never paint an antenna, without asking any questions. could I use a
> different antenna than the RAMI brand? should I not worry about any of th
is
> and just go fly?
>
>
Message 2
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Subject: | Re: what is the truth about gps antennas? |
3dB is a doubling of whatever you measure. (Actually a factor of 10^0.3 =
1.995)
Of course you have to say what you=99re comparing with, so we talk ab
out dBA, dBV, dBm, for sound level relative to the quietest detectable by th
e human ear, volts, or power (in mW), respectively.
If you=99re talking about Voltage then 40dB is by definition a ratio o
f 10,000 to 1. Which, into the same load impedance corresponds to a power ra
tio of 10^8 to 1.
On Dec 23, 2018, at 09:04, FLYaDIVE <flyadive@gmail.com> wrote:
Alec:
I did say "Rule of Thumb". I did not look up if the dB gain expressed in th
e manual is voltage or power, but I'm pretty sure it would be voltage. And t
he rule of thumb is the voltage signal will double with every 3 dB of gain.
Ya got me... I did not sit down with my slide rule and work out the voltag
e gain, I am just trying to show a relative number that non engineers can w
ork with.
But, your numbers are incorrect. A 10,000:1 dB ratio gain would be more lik
e 80 dB's not 40 dB's.
See: Common Gains and Losses Expressed in Decibels
http://www.sengpielaudio.com/calculator-FactorRatioLevelDecibel.htm
Barry
> On Sat, Dec 22, 2018 at 11:31 PM Alec Myers <alec@alecmyers.com> wrote:
> 40dB is 40/3 = 13.3 doublings, or a ratio of 2^13.3, which is about 10,0
00, as you say.
>
> On Dec 22, 2018, at 21:10, Henador Titzoff <henador_titzoff@yahoo.com> wro
te:
>
> It's an old wive's tale that a 40 dB gain is 40/3 = 13 times power gain o
ver 0 dB.
>
> The decibel is a ratio of two physical properties expressed mathematically
using logarithmic base 10. When referring to power, below are the calculat
ed values using the equation dB = 10xLog10(P/Po):
>
> 0 dB = 1
> 3 dB = 1.995 = ~2
> 6 dB = 3.981 = ~4
> 9 dB = 7.95 = ~8
> 10 dB = 10.0
> 20 dB = 100.0
> 30 dB = 1000.0
> 40 dB = 10,000.0
>
> So 40 DB represents a ratio of 10,000, not 13. If 0 dB = 1 milliWatt, t
hen 40 dB = 10 Watts.
>
> Everything else you say below is correct except that RF engineers, as well
as LiDAR engineers, refer to too much signal as saturation, not splatter. M
aybe I'm hanging out with a different bunch of engineers, but we use what th
e literature says.
>
> Henador Titzoff
>
>
> On Saturday, December 22, 2018, 8:03:24 PM EST, FLYaDIVE <flyadive@gmail.c
om> wrote:
>
>
> Hi Kevin:
>
>
> You are 300% right to question Old Wive's Tails.
> The Paint Story is not without some merit. It stems from the idea of how t
he Color was produced. Black and Gray for example could come from a CARBON.
Carbon is conductive, not highly so but conductive. After all Carbon Resi
stors are exactly that Carbon and Conductive.
> The old Green, Copper and Bronze have Copper and Bronze metals in them.
> White paint can have Titanium Dioxide in it and titanium is metal and slig
htly conductive.
> There are also paints such as primers which have Zinc in them.
> Well, you can see the thought process, that conductive paints can cause so
me problems.
> So, why take the chance... The industry makes a general Old Wive's Tail s
tatement of Do Not Paint GPS Antennas.
> Of course the Pigment of paints have changed over the years, too bad the O
ld Wive's Tails have a stronger following than the process of common sense.
> What YOU can do is read the Ingredients List of what makes the paint the c
olor (Pigment) and see if any of the above items are listed. ALSO, you can l
ook up the MSDS for the paint.
>
> Next: -
> OVER DRIVEN: - We should be so lucky.
> YES! There is such a thing. It is also know in Receiver Theory as Front E
nd Over Load.
> Too much signal is received and causes SPLATTER - Too much signal covering
too wide a bandwidth.
> The 'Active" GPS Antennas do have amplifiers built into them. They usua
lly range between 10 to 40 dB Gain.
> The rule of dB is every 3 dB doubles your signal. So, YES, in theory if yo
u have a 40 dB gain antenna you could have 40/3 = 13 times the un-amplifie
d signal. That could be too much for the receiver to handle.
> Of course there is a loss in the coax, loss in each of the connectors and a
n additional loss in the 90 Deg connector.
> So, if an engineer sits down with the slide-ruler the NUMBERS would say YE
S, there is too much signal coming down the RG-400. SO! Why not be smarter t
han the Engineer - Save your Money - Buy RG-58/AU and run the shortest lengt
h possible? Buy It - HELL! I have a 150 foot spool! But NOooooo.... Com
mon Sense is over ruled by Sales Pitch and owners spend $4.00 per foot for R
G-400 and they buy 10 foot when only 3 foot is need for the run. 10 Foot @ $
4 = $40 Vs 3 Foot @ $0.75 = $2.25.
> So Kevin, you did VERY - VERY GOOD!
>
> Guess What! I did the EXACT same thing with the Stratus ESG coax situatio
n as you. I also mounted it on my Glare Shield. But, I have a carper over t
he antenna so I did not have to paint the antenna.
>
> Works Great, Works Fine - FM!
>
> Barry
>
>
> message posted by: "kjlpdx" <kevinlane55@gmail.com>
>>
>> I'm interested in hearing from an engineer who might know about what real
ly goes on with my stratus esg gps antenna. they say to use RG400 cable, 10'
minimum, and never paint the antenna. they also told me the strength rating
s should run in the 30's. I have 3' of RG400 with a mechanical 90=C3=82=C2=B0
elbow, I spray painted the antenna flat black and mounted it on the glaresh
ield of my RV. my readings are all in the 40's. they told me this shows an o
verdriven condition.
>> so why use low impedance cable then need 10'? my iFly740 and Lowrance 100
0 gps's have antennas with much smaller cables. the iFly shows WAAS grade ac
curacy, using an antenna 1/4 the size of the stratus RAMI antenna.
>> when does being overdriven prove to be a problem? is this a situation whe
re I could add more mechanical connectors to increase impedance rather than m
ore cable length?
>> I get the feeling things get written and then forever repeated, such as n
ever paint an antenna, without asking any questions. could I use a different
antenna than the RAMI brand? should I not worry about any of this and just g
o fly?
>
Message 3
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Subject: | Re: what is the truth about gps antennas? |
>3dB is a doubling of whatever you measure. (Actually a factor of 10^0.3 = 1.995)
I see this is actually true only for power quantities and power-like quantities.
For field quantities and field-like quantities 3dB is a ratio of 10^0.15 = 1.41.
So a signal ratio of 40dB is ten thousand times the power and 100 times the
voltage.
Thats what you get when you put the engineers in charge of defining units instead
of the physicists...
Message 4
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Subject: | Re: what is the truth about gps antennas? |
>
> That=99s what you get when you put the engineers in charge of defin
ing units
> instead of the physicists...
>
I TOTALLY AGREE!
I have NEVER seen a more argumentative bunch than Engineers.
They all went to collage.
They all took the same courses.
They all learned the SAME physics. <-- Well,they should have!
They all learned the same electronics.
Yet they disagree on more things than Congress.
Three Engineers, an Electrical Engineer, a Mechanical Engineer and a Civil
Engineer were discussing what kind of an engineer GOD must be.
The Electrical Engineer said: He must be an Electrical Engineer, think
about it:
And consider the miles of nerve courses in the body. Consider all the
nerve endings. Consider all the synapse=99s in the brain sending ele
ctrical
impulses all throughout the body. GOD is an Electrical Engineer!
The Mechanical Engineer spoke up and said: He must be a Mechanical
Engineer, think about it:
And consider all of the bones throughout the body. Consider all the
muscles pulling against each other supporting the bones. Consider how all
the bones and muscles can reproduce as they become weak or damaged. GOD is
a Mechanical Engineer!
Then the Civil Engineer spoke up and said: He MUST be a Civil Engineer
=93
And with that the other two engineers broke into a raucous laughter. Again
the Civil Engineer spoke up and said: Think about it:
Who else other than a Civil Engineer would put a waste dump right around
the corner from a playground?
Barry
Message 5
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Subject: | Re: what is the truth about gps antennas? |
There was a fourth person in the story, a politician, who went last. He
said, =9CGod was most certainly a politician. The Bible says in the b
eginning
there was chaos. Who do you think created the chaos?=9D
Lyn
On Sun, Dec 23, 2018 at 08:18 FLYaDIVE <flyadive@gmail.com> wrote:
> That=99s what you get when you put the engineers in charge of defin
ing units
>> instead of the physicists...
>>
>
> I TOTALLY AGREE!
>
> I have NEVER seen a more argumentative bunch than Engineers.
> They all went to collage.
> They all took the same courses.
> They all learned the SAME physics. <-- Well,they should have!
> They all learned the same electronics.
> Yet they disagree on more things than Congress.
>
> Three Engineers, an Electrical Engineer, a Mechanical Engineer and a Civi
l
> Engineer were discussing what kind of an engineer GOD must be.
>
> The Electrical Engineer said: He must be an Electrical Engineer, think
> about it:
>
> And consider the miles of nerve courses in the body. Consider all the
> nerve endings. Consider all the synapse=99s in the brain sending e
lectrical
> impulses all throughout the body. GOD is an Electrical Engineer!
>
>
> The Mechanical Engineer spoke up and said: He must be a Mechanical
> Engineer, think about it:
>
> And consider all of the bones throughout the body. Consider all the
> muscles pulling against each other supporting the bones. Consider how al
l
> the bones and muscles can reproduce as they become weak or damaged. GOD
is
> a Mechanical Engineer!
>
>
> Then the Civil Engineer spoke up and said: He MUST be a Civil Engineer
=93
> And with that the other two engineers broke into a raucous laughter. Aga
in
> the Civil Engineer spoke up and said: Think about it:
>
> Who else other than a Civil Engineer would put a waste dump right around
> the corner from a playground?
>
>
> Barry
>
Message 6
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Subject: | Z-14 Switches Preferred... |
My first post. I have to assume this has been checked out before, but could not
find it...
>From my fresh copy of AeroElectric Connection, I have found some surprises...
and I am not accustomed to doing circuit design - I am a Mechanical Engineer.
Firstissue:
Page 11-21, Fig 11-22 is supposed to be an excerpt from Z-14 (which I plan to use
on my electrically dependent engine IFR ship) showing a diode bridge for operation
of the cross feed contactor;
Appendix Z-14 in my book shows three 1N5400 diodes.
Tracing the diodes in each case, these appear to be the same electrically, but
which is the preferred set of parts for this system?
Second issue. The starter cross feed switch on Z-14:
In Appendix Z-14, the switch is labeled S700-2-7, with a Circle L, yet the drawing
shows momentary-on the start side but stays on in the cross feed position.
2-7 is an (ON)-OFF-(ON) switch, not the (ON)-OFF-ON shown which seems to be an
S700-2-5. Does the circuit self-energize and so does not need the switch to
stay the Crossfeed position? If yes, does it disconnect when we turn off both
masters?
Then on page 17-10, Bob proposes the S700-2-50 for the combined starter and cross
feed.
So, which switch is the now current right way to build this circuit? Do I use a
diode bridge or three 1N5400 diodes? Do I use the 2-7, the 2-5, or the 2-50?
And "for extra credit", why do we go with each version?
Bill Simpson
Message 7
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Subject: | Re: what is the truth about gps antennas? |
On Sun, Dec 23, 2018 at 12:01 PM Lyn Robertson <lyn.robertson@gmail.com>
wrote:
> There was a fourth person in the story, a politician, who went last. He
> said, =9CGod was most certainly a politician. The Bible says in the
beginning
> there was chaos. Who do you think created the chaos?=9D
>
> Lyn
>
But Politicians are not Engineers. For if they were, an engineer, they
would have invented a better way to cover their ass, other than by rhetoric
and at the people's expense.
Barry
Message 8
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Subject: | Re: Z-14 Switches Preferred... |
On Dec 23, 2018, 12:10 PM, at 12:10 PM, Bill Simpson <wsimpso1@comcast
=2Enet> wrote:
>My first post=2E I have to assume this has been checked out
before, but
>could not find it=2E=2E=2E
>
>
>>From my fresh copy of AeroEl
ectric Connection, I have found some
>surprises=2E=2E=2E and I am not accus
tomed to doing circuit design - I am a
>Mechanical Engineer=2E Firstissue:
>
>
>Page 11-21, Fig 11-22 is supposed to be an excerpt from Z-14 (which I
>plan to use on my electrically dependent engine IFR ship) showing a
>diode
bridge for operation of the cross feed contactor;
>
>
>Appendix Z-14 in my
book shows three 1N5400 diodes=2E
>
>
>Tracing the diodes in each case, th
ese appear to be the same
>electrically, but which is the preferred set of
parts for this system?
>
>
>Second issue=2E The starter cross feed switch
on Z-14:
>
>
>In Appendix Z-14, the switch is labeled S700-2-7, with a Circ
le L, yet
>the drawing shows momentary-on the start side but stays on in th
e cross
>feed position=2E 2-7 is an (ON)-OFF-(ON) switch, not the (ON)-OFF-
ON
>shown which seems to be an S700-2-5=2E Does the circuit self-energize a
nd
>so does not need the switch to stay the Crossfeed position? If yes,
>do
es it disconnect when we turn off both masters?
>
>
>Then on page 17-10, B
ob proposes the S700-2-50 for the combined starter
>and cross feed=2E
>
>
>So, which switch is the now current right way to build this circuit? Do
>I
use a diode bridge or three 1N5400 diodes? Do I use the 2-7, the 2-5,
>or
the 2-50? And "for extra credit", why do we go with each version?
>
>
>Bill
Simpson
Message 9
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Subject: | Re: what is the truth about gps antennas? |
While were on the subject.
A mathematician, a physicist and an engineer are all asked to examine the hypothesis
that all odd numbers are prime.
The mathematician goes first, saying as follows:
One is prime, three is prime, five is prime, seven is prime, nine ISNT prime, so
the hypothesis fails by counterexample.
Then the physicist, who says:
One is prime, three is prime, five is prime, seven is prime, nine isnt prime, but
well call it experimental error, eleven is prime and thirteen is prime. Thats
enough for me. I accept the hypothesis as true.
Finally the engineer steps up.
One is prime, three is prime, five is prime, seven is prime, nine is prime.
And heres one for the maths nerds amongst us:
Q: Whats green and commutes?
A: An Abeilan grape.
On Dec 23, 2018, at 1:00 PM, FLYaDIVE <flyadive@gmail.com> wrote:
On Sun, Dec 23, 2018 at 12:01 PM Lyn Robertson <lyn.robertson@gmail.com> wrote:
There was a fourth person in the story, a politician, who went last. He said, God
was most certainly a politician. The Bible says in the beginning there was
chaos. Who do you think created the chaos?
Lyn
But Politicians are not Engineers. For if they were, an engineer, they would have
invented a better way to cover their ass, other than by rhetoric and at the
people's expense.
Barry
Message 10
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Subject: | Re: Z-14 Switches Preferred... |
My crossfeed does close automatically during cranking if either (or
both) batteries are available.
I have an older version of Z-14 which also incorporates a little 30 amp
automotive relay in the control circuit. It uses a simple ON -OFF switch
that will close the crossfeed whether the battery master is on or off.
(My crossfeed contactor is fed by both hot batt buss's and don't require
the battery master to be on). I leave that crossfeed switch OFF at all
times unless one alternator has failed.
I think you are referring to a later circuit utilizing a 3 position
crossfeed switch. It has a continuous ON, OFF, or momentary crank the
engine position. I would leave that switch in the OFF position unless
cranking or after losing one alternator. The 3 diodes insure that
current from either side of Z-14 can close the contactor. Normally
operating with the crossfeed contactor open insures that your low
voltage warning devices will immediately warn you if one alternator
drops offline.
Ken
On 23/12/2018 2:00 PM, Charlie England wrote:
>
>
> On Dec 23, 2018, at 12:10 PM, Bill Simpson <wsimpso1@comcast.net
> <mailto:wsimpso1@comcast.net>> wrote:
>
> My first post. I have to assume this has been checked out before,
> but could not find it...
>
>
> From my fresh copy of AeroElectric Connection, I have found some
> surprises... and I am not accustomed to doing circuit design - I
> am a Mechanical Engineer. Firstissue:
>
>
> Page 11-21, Fig 11-22 is supposed to be an excerpt from Z-14
> (which I plan to use on my electrically dependent engine IFR ship)
> showing a diode bridge for operation of the cross feed contactor;
>
>
> Appendix Z-14 in my book shows three 1N5400 diodes.
>
>
> Tracing the diodes in each case, these appear to be the same
> electrically, but which is the preferred set of parts for this
> system?
>
>
> Second issue. The starter cross feed switch on Z-14:
>
>
> In Appendix Z-14, the switch is labeled S700-2-7, with a Circle L,
> yet the drawing shows momentary-on the start side but stays on in
> the cross feed position. 2-7 is an (ON)-OFF-(ON) switch, not the
> (ON)-OFF-ON shown which seems to be an S700-2-5. Does the circuit
> self-energize and so does not need the switch to stay the
> Crossfeed position? If yes, does it disconnect when we turn off
> both masters?
>
>
> Then on page 17-10, Bob proposes the S700-2-50 for the combined
> starter and cross feed.
>
>
> So, which switch is the now current right way to build this
> circuit? Do I use a diode bridge or three 1N5400 diodes? Do I use
> the 2-7, the 2-5, or the 2-50? And "for extra credit", why do we
> go with each version?
>
>
> Bill Simpson
>
> Hi Bill,
>
>
> I don't have my book handy, but the 5400 diode(s) are rated at 3A,
> while you can buy almost any rating for the diode block. The block
> is also easier to mount, and easier to heatsink, if required,
> while the 5400s must be soldered to some kind of support. Your
> application would determine what is best for you.
>
> Charlie
>
>
Message 11
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Subject: | Re: Z-14 Switches Preferred... |
>
>
>Appendix Z-14 in my book shows three 1N5400 diodes.
>
>
>Tracing the diodes in each case, these appear to be the same
>electrically, but which is the preferred set of parts for this system?
Either works fine . . . your choice.
>Second issue. The starter cross feed switch on Z-14:
>
>
>In Appendix Z-14, the switch is labeled S700-2-7, with a Circle L,
>yet the drawing shows momentary-on the start side but stays on in
>the cross feed position. 2-7 is an (ON)-OFF-(ON) switch, not the
>(ON)-OFF-ON shown which seems to be an S700-2-5. Does the circuit
>self-energize and so does not need the switch to stay the Crossfeed
>position? If yes, does it disconnect when we turn off both masters?
>
>
>Then on page 17-10, Bob proposes the S700-2-50 for the combined
>starter and cross feed.
>
>
>So, which switch is the now current right way to build this circuit?
>Do I use a diode bridge or three 1N5400 diodes? Do I use the 2-7,
>the 2-5, or the 2-50? And "for extra credit", why do we go with each version?
2-50 and 2-7 are errors. The latest drawing on
the website shows that the error was corrected
when 2-5 was called out at revision P
Emacs!
Bob . . .
Message 12
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Subject: | Re: what is the truth about gps antennas? |
You have a better way to cover your rear than at other people's expense?
On Sunday, December 23, 2018, 1:02:34 PM EST, FLYaDIVE <flyadive@gmail.
com> wrote:
On Sun, Dec 23, 2018 at 12:01 PM Lyn Robertson <lyn.robertson@gmail.com> wr
ote:
There was a fourth person in the story, a politician, who went last. He sai
d, =9CGod was most certainly a politician. The Bible says in the begi
nning there was chaos.=C2- Who do you think created the chaos?=9D
Lyn
But Politicians are not Engineers.=C2- For if they were, an engineer, the
y would have invented a better way to cover their ass, other than by rhetor
ic and at the people's expense.
Barry
Message 13
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Subject: | Re: what is the truth about gps antennas? |
Ernest:
You are 100% correct. Sad but true, why do what's right when you can do
what you want and put the blame on someone else. Why dip into your own
pocket when you can steal from someone else. AND steal legally!
Barry
On Sun, Dec 23, 2018 at 10:53 PM Ernest Christley <echristley@att.net>
wrote:
> You have a better way to cover your rear than at other people's expense?
>
> On Sunday, December 23, 2018, 1:02:34 PM EST, FLYaDIVE <flyadive@gmail.co
m>
> wrote:
>
>
> On Sun, Dec 23, 2018 at 12:01 PM Lyn Robertson <lyn.robertson@gmail.com>
> wrote:
>
> There was a fourth person in the story, a politician, who went last. He
> said, =9CGod was most certainly a politician. The Bible says in the
beginning
> there was chaos. Who do you think created the chaos?=9D
>
> Lyn
>
>
> But Politicians are not Engineers. For if they were, an engineer, they
> would have invented a better way to cover their ass, other than by rhetor
ic
> and at the people's expense.
>
> Barry
>
>
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