Today's Message Index:
----------------------
0. 10:10 AM - Just A Few Days Left... (Matt Dralle)
1. 01:05 AM - Re: Intercom volume (Bill Maxwell)
2. 06:45 AM - Re: Troubleshooting radio whine/noise on Cessna 182P (user9253)
3. 07:03 AM - Re: Troubleshooting radio whine/noise on Cessna 182P (sacha)
4. 07:27 AM - Re: Re: Troubleshooting radio whine/noise on Cessna 182P (Jan)
5. 07:34 AM - Re: Troubleshooting radio whine/noise on Cessna 182P (sacha)
6. 07:55 AM - Re: Re: Troubleshooting radio whine/noise on Cessna 182P (Neal George)
7. 08:07 AM - Re: Re: Troubleshooting radio whine/noise on Cessna 182P (Jan)
8. 08:39 AM - Re: Troubleshooting radio whine/noise on Cessna 182P (sacha)
9. 08:43 AM - Re: Troubleshooting radio whine/noise on Cessna 182P (user9253)
10. 08:56 AM - Re: Troubleshooting radio whine/noise on Cessna 182P (sacha)
11. 10:12 AM - Re: Troubleshooting radio whine/noise on Cessna 182P (paulmillner)
12. 10:40 AM - Re: Troubleshooting radio whine/noise on Cessna 182P (sacha)
13. 11:15 AM - Re: Re: Troubleshooting radio whine/noise on C essna 182P (jan)
14. 11:18 AM - Re: Re: Troubleshooting radio whine/noise on Cessna 182P (Charlie England)
15. 02:59 PM - Re: Troubleshooting radio whine/noise on Cessna 182P (user9253)
16. 04:25 PM - Re: Troubleshooting radio whine/noise on Cessna 182P (sacha)
17. 04:35 PM - Re: Troubleshooting radio whine/noise on Cessna 182P (sacha)
18. 05:14 PM - Re: Re: Troubleshooting radio whine/noise on Cessna 182P (Paul Millner)
19. 05:18 PM - Re: Re: Troubleshooting radio whine/noise on Cessna 182P (neal.george@gmail.com)
20. 06:16 PM - Re: Troubleshooting radio whine/noise on Cessna 182P (sacha)
21. 07:53 PM - Re: Re: Troubleshooting radio whine/noise on Cessna 182P (Charlie England)
22. 10:40 PM - Re: Rotax ignition wiring (jrevens)
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Subject: | Just A Few Days Left... |
Dear Listers,
There are just a few days left for this year's List Fund Raiser. If you've been
putting off making a Contribution until the last minute, well, this is it!
The last minute, that is... :-) There are some GREAT new gift selections to choose
from this year. I personally want at least three of them! There's probably
something you can't live without too! And, best of all it supports your
Lists!
Please remember that there isn't any sort of commercial advertising on the Lists
and the *only* means of keeping these Lists running is through your Contributions
during this Fund Raiser. Let's make this a "Black Friday" for the Lists!
Please make a Contribution today!
http://www.matronics.com/contribution
Or, drop a personal check in the mail to:
Matt Dralle / Matronics
581 Jeannie Way
Livermore CA 94550
Thank you!
Matt Dralle
Matronics Email List Administrator
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Subject: | Re: Intercom volume |
In theory yes but you can probably wind up the volume control to
compensate, Stu. If you have a 4 place intercom and dont usethe full
four places, probably wont be an issue anyway?
Bill
On 24/11/2015 5:55 PM, Stuart Hutchison wrote:
>
> Gday.
>
> Can someone please confirm whether the intercom signal (i.e. volume) is diluted
by connecting other recording devices in parallel with the main intercom jacks?
Id like to hardwire one or two sockets to connect multiple GoPro cameras
to the intercom, but not if it will significantly degrade system performance.
>
> Cheers, Stu
>
>
>> On 24 Nov 2015, at 3:35 PM, user9253 <fransew@gmail.com> wrote:
>>
>>
>> Microphone jacks should be insulated from the airframe. The coax should be
grounded at the avionics end only.
>>
>> --------
>> Joe Gores
>
>
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
If no problem is found with the aircraft wiring or components, you might consider a filter (if legal on a 182). This website tells how to make your own filter: http://www.sanantoniohams.org/tips/whine.htm
Or you can buy a pre-wound toroid (rated for load current) and add a capacitor
at the avionics end.
Mouser and eBay sell both bare and pre-wound toroids.
Mouser part number: 704-CTX100-2-52LP-R
eBay item numbers: 400433590605, 191743622176, 370777920139
I am not necessarily recommending a filter but it might be worth a try if all else
fails.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450093#450093
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
Thanks. There is already an inductive and a capacitive noise filter on the 182.
What I'm thinking of though is: two weeks ago (before the ALT breaker popped in
flight) everything was fine. So that breaker popping and then the noise appearing
as soon as I reset the breaker on the ground must mean that *SOMETHING*
has changed: it's unlikely to be the mic/phone jacks so I'm wondering what it
could be that was damaged/changed:
- could it be that the noise filters were fried by an over-voltage event? (but
if it was an overvoltage event, the ALT reg CB should have popped, not the ALT
CB).
There were actually two problems:
- low bus voltage
- noise
Replacing the alternator solved neither. On Friday, my A&P made a temporary installation
of a new voltage regulator and that solved the low voltage problem.
But that installation did not allow the alternator to go offline when the ALT
rocker switch was turned off. Yesterday, he finished the installation and verified
that when the ALT is turned off, the noise disapears. But the interesting
thing is that he mentioned that the bus voltage is now 13.5V vs 14.1V on
Friday. So I'm now suspecting that the ALT rocker switch is offering some unusual
resistance.
Could that have been caused by whatever caused the ALT breaker to pop?
I guess the next step is to bypass the ALT rocker switch and see if at least the
bus voltage returns to 14.1V. Thoughts?
The electrical schematic is on p.18 (numbered 2-4) of http://www.t-craft.org/Fleet/C182P-POH.pdf
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450095#450095
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Subject: | Re: Troubleshooting radio whine/noise on Cessna |
182P
Stupid question maybe but is the new voltage regulator identical to the old unit
?
All the best
Jan
> On Nov 24, 2015, at 15:02, sacha <uuccio@gmail.com> wrote:
>
>
> Thanks. There is already an inductive and a capacitive noise filter on the 182.
>
> What I'm thinking of though is: two weeks ago (before the ALT breaker popped
in flight) everything was fine. So that breaker popping and then the noise appearing
as soon as I reset the breaker on the ground must mean that *SOMETHING*
has changed: it's unlikely to be the mic/phone jacks so I'm wondering what it
could be that was damaged/changed:
> - could it be that the noise filters were fried by an over-voltage event? (but
if it was an overvoltage event, the ALT reg CB should have popped, not the
ALT CB).
>
> There were actually two problems:
> - low bus voltage
> - noise
> Replacing the alternator solved neither. On Friday, my A&P made a temporary
installation of a new voltage regulator and that solved the low voltage problem.
But that installation did not allow the alternator to go offline when the
ALT rocker switch was turned off. Yesterday, he finished the installation and
verified that when the ALT is turned off, the noise disapears. But the interesting
thing is that he mentioned that the bus voltage is now 13.5V vs 14.1V on
Friday. So I'm now suspecting that the ALT rocker switch is offering some unusual
resistance.
> Could that have been caused by whatever caused the ALT breaker to pop?
>
> I guess the next step is to bypass the ALT rocker switch and see if at least
the bus voltage returns to 14.1V. Thoughts?
>
> The electrical schematic is on p.18 (numbered 2-4) of http://www.t-craft.org/Fleet/C182P-POH.pdf
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=450095#450095
>
>
>
>
>
>
>
>
>
>
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
Hi Jan
No it isn't. The old one is a Ford. The new one a Plane Power regulator.
Can you explain why you're asking?
Sacha
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450097#450097
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Subject: | Re: Troubleshooting radio whine/noise on Cessna |
182P
Sasha -
The PlanePower voltage regulators are adjustable, and must be adjusted at installation.
It would probably be a good idea to replace the Split Master switch, too.
neal
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of sacha
Sent: Tuesday, November 24, 2015 9:33 AM
Subject: AeroElectric-List: Re: Troubleshooting radio whine/noise on Cessna 182P
Hi Jan
No it isn't. The old one is a Ford. The new one a Plane Power regulator.
Can you explain why you're asking?
Sacha
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Subject: | Re: Troubleshooting radio whine/noise on Cessna |
182P
Well, depending on the technology used for the voltage regulation - the noise can
be generated by the regulator.
The noise filter that you currently have fitted would have been tuned to the old
regulator - new regulator could very well need a new filter, tuned for the
current regulator.
If the noise pitch is changing with rpm - that would sound to me as if the noise
is from the regulator as it does its work regulating the output voltage
All the best
Jan
> On Nov 24, 2015, at 15:53, Neal George <ngeorge@continentalmotors.aero> wrote:
>
>
> Sasha -
> The PlanePower voltage regulators are adjustable, and must be adjusted at installation.
> It would probably be a good idea to replace the Split Master switch, too.
>
> neal
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of sacha
> Sent: Tuesday, November 24, 2015 9:33 AM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Re: Troubleshooting radio whine/noise on Cessna 182P
>
>
> Hi Jan
> No it isn't. The old one is a Ford. The new one a Plane Power regulator.
> Can you explain why you're asking?
> Sacha
>
>
>
>
>
>
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
Thank you for your inputs.
I'm sorry it's a little difficult for me to know exactly what is going on as I
am receiving reports from the A&P, not working on the plane directly (as I a not
allowed to).
I just got another email from the A&P saying that after multiple calls to Plane
Power they think they have it correctly installed, but there is some concern
that the bus voltage is very slow to come up. Could this be due in any way to
a defect of the over voltage protection?
Hmmmm.... maybe the most expeditious solution would be to install a Ford regulator
and a new master switch.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450101#450101
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
Using the voltage regulator CASE as a reference point (not the airframe or battery
negative), measure the voltage on the regulator "sense" terminal. Is it the
same as battery voltage? If not, find out where the voltage is being dropped.
Over-voltage can destroy capacitors. The capacitors could be tested to make
sure they are OK.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450102#450102
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
Ok things are even more complicated as I just noticed that the plane power regulator
has internal over voltage protection and so the over voltage protection
on the a/c must now be bypassed.
I get the feeling that I'm gonna have to carefully read the instructions and make
sure that they are being followed by the shop!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450104#450104
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
sacha wrote:
> Ok things are even more complicated as I just noticed that the plane power regulator
has internal over voltage protection and so the over voltage protection
on the a/c must now be bypassed.
>
> I get the feeling that I'm gonna have to carefully read the instructions and
make sure that they are being followed by the shop!
Hi Sacha,
Why can't you work on your own airplane, under A&P supervision? Who does not "allow"
you to?
You have to verify that the old OV relay was removed... it could be defective and
causing your regulation problem.
You do NOT want a Ford automotive regulator... it can cause an overvoltage situation
that even an external OV relay cannot overcome (the automotive regulator
sources regulator power directly from the alternator, and thus ignores whether
the OV relay or alternator half of the master switch are providing power, or
not.)
Paul
--------
Paul Millner, Berkeley CA [OAK]
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450106#450106
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
You're right Paul - that's a good idea. Problem is I Guest I would have to take
time off work during weekdays (when the A&P is around) but I can't right now.
The old OV system has been removed and the bus voltage is now 14.2V.
So now we just have to figure out where the noise is entering the system.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450187#450187
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Subject: | Re: Troubleshooting radio whine/noise on C essna |
182P
My money is on the regulator for the noise ... I do not think changing the
master switch will solve your noise problem ... Prove it by just shorting
out the switch !.. Or temporary mount any old 'toggle switch' to just prove
the point ....
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of sacha
Sent: 24 November 2015 16:38
Subject: AeroElectric-List: Re: Troubleshooting radio whine/noise on Cessna
182P
Thank you for your inputs.
I'm sorry it's a little difficult for me to know exactly what is going on as
I am receiving reports from the A&P, not working on the plane directly (as I
a not allowed to).
I just got another email from the A&P saying that after multiple calls to
Plane Power they think they have it correctly installed, but there is some
concern that the bus voltage is very slow to come up. Could this be due in
any way to a defect of the over voltage protection?
Hmmmm.... maybe the most expeditious solution would be to install a Ford
regulator and a new master switch.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450101#450101
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Subject: | Re: Troubleshooting radio whine/noise on Cessna |
182P
On 11/24/2015 12:39 PM, sacha wrote:
>
> You're right Paul - that's a good idea. Problem is I Guest I would have to take
time off work during weekdays (when the A&P is around) but I can't right now.
>
> The old OV system has been removed and the bus voltage is now 14.2V.
>
> So now we just have to figure out where the noise is entering the system.
>
'Under supervision' doesn't mean that he has to stand there looking over
your shoulder. As long as he's willing to sign on the dotted line at the
end of the process, you could rebuild the entire a/c while he's
vacationing in Tahiti.
From a previous post:
>>
You do NOT want a Ford automotive regulator... it can cause an overvoltage situation
that even an external OV relay cannot overcome (the automotive regulator
sources regulator power directly from the alternator, and thus ignores whether
the OV relay or alternator half of the master switch are providing power, or
not.)
>>
I can't make sense of this, as long as we're talking about an externally
regulated alternator. Ford style regulators are flying in thousands of
homebuilts safely (assuming that OV protection is used). As long as the
wire to the field is interrupted, the alternator cannot produce power.
Typical OV protection circuits either open the field lead or 'crowbar'
it to ground, tripping the field circuit breaker (which breaks the field
circuit). Either way, there's no way for the regulator to keep the
alternator operating.
For noise: What's the ground path from the alternator frame to the
battery, and from the regulator negative to the battery? (Make sure
neither uses the motor mount as part of the circuit.) What's the ground
path back to the battery of the radio where you're hearing the noise?
If the noise is happening in receive mode on the radio, try
disconnecting the antenna coax from the radio (don't transmit while it's
disconnected). If the noise stays the same, the noise is probably
entering through the B+ lead or the ground. If the noise goes away, it's
probably being radiated from the alternator and/or the regulator into
the antenna or coax. Check the coax ground for continuity and check the
antenna mount for proper grounding.
Charlie
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
For testing purposes, temporarily connect a 12 AWG jumper wire from the alternator
"B" terminal to the avionics bus and listen to see if the whine goes away.
If that is not doable, measure the voltage between the alternator "B" terminal
and the avionics bus while the engine is running and all electrical loads are
turned on. I would expect that voltage drop to be only millivolts.
Is measuring voltage considered "working" on an airplane?
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450193#450193
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
Charles/Joe,
thanks. I will do the antenna coax test, and, assuming it's not entering via the
antenna, I'll do the test that Joe recommended by connecting the B-lead and
the avionics bus.
On the ground side of things, the alternator is tied to the engine crankcase which
is tied to the airframe. The battery is rear mounted and locally grounded
to the airframe. I think the best i can do there is to check each connection
to make sure it's in tip-top condition and appropriately greased to prevent corrosion.
I'll also check the capacitors that mounted on the B-lead so see if they are still
operational.
Sacha
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450195#450195
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
Neal,
thank you for that. I only just saw your post. It looks like the issue with the
regulator has been sorted out. I'm guessing the master switch is fine too
but I'll bypass it in a test just to be sure.
Sacha
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450197#450197
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Subject: | Re: Troubleshooting radio whine/noise on Cessna |
182P
Charlie,
The problem is that you're not aware of how Cessna wired the regulator
in this 182...
Instead of the OV relay interrupting the current path between the
regulator and the field terminal as you propose OBAM folks usually do
it, the OV relay and the alternator half of the master switch interrupt
the power supply *to* the regulator, via the S or Supply terminal.
However... the automotive version supplies the regulator and alternator
from both the S and the A terminal... and once the master is on, the A
terminal is hot... so the Cessna OV relay and alternator half of the
master switch are irrelevant.
So... an automotive regulator in the Cessna wiring diagram? The
alternator is non-controllable... which could be a bad thing.
See attached wiring diagram.
Paul
http://www.secure4host.net/upload/files/Cessna_Alternator_Wiring.pdf
On 11/24/2015 11:18 AM, Charlie England wrote:
> You do NOT want a Ford automotive regulator... it can cause an
> overvoltage situation that even an external OV relay cannot overcome
> (the automotive regulator sources regulator power directly from the
> alternator, and thus ignores whether the OV relay or alternator half
> of the master switch are providing power, or not.)
>
>>>
>
> I can't make sense of this, as long as we're talking about an
> externally regulated alternator. Ford style regulators are flying in
> thousands of homebuilts safely (assuming that OV protection is used).
> As long as the wire to the field is interrupted, the alternator cannot
> produce power. Typical OV protection circuits either open the field
> lead or 'crowbar' it to ground, tripping the field circuit breaker
> (which breaks the field circuit). Either way, there's no way for the
> regulator to keep the alternator operating.
>
>
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Subject: | Re: Troubleshooting radio whine/noise on Cessna |
182P
I don't suggest that it is contributing to the noise problem, but I DO suspect
it is old and has tarnished / corroded contacts that add resistance to the circuit.
Could contribute to the voltage sensing and regulation issues...
Neal George
Sent from my iPhone
> On Nov 24, 2015, at 6:34 PM, sacha <uuccio@gmail.com> wrote:
>
>
> Neal,
> thank you for that. I only just saw your post. It looks like the issue with
the regulator has been sorted out. I'm guessing the master switch is fine too
but I'll bypass it in a test just to be sure.
> Sacha
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=450197#450197
>
>
>
>
>
>
>
>
>
>
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Subject: | Re: Troubleshooting radio whine/noise on Cessna 182P |
Good point. It's not a big ticket item (thought $40 seems a lot for two switches)
so I guess I ought to swap it out.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450200#450200
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Subject: | Re: Troubleshooting radio whine/noise on Cessna |
182P
Uh...I stand corrected. Shame Cessna can't be.
On 11/24/2015 7:13 PM, Paul Millner wrote:
> Charlie,
>
> The problem is that you're not aware of how Cessna wired the regulator
> in this 182...
>
> Instead of the OV relay interrupting the current path between the
> regulator and the field terminal as you propose OBAM folks usually do
> it, the OV relay and the alternator half of the master switch
> interrupt the power supply *to* the regulator, via the S or Supply
> terminal.
>
> However... the automotive version supplies the regulator and
> alternator from both the S and the A terminal... and once the master
> is on, the A terminal is hot... so the Cessna OV relay and alternator
> half of the master switch are irrelevant.
>
> So... an automotive regulator in the Cessna wiring diagram? The
> alternator is non-controllable... which could be a bad thing.
>
> See attached wiring diagram.
>
> Paul
>
> http://www.secure4host.net/upload/files/Cessna_Alternator_Wiring.pdf
>
> On 11/24/2015 11:18 AM, Charlie England wrote:
>> You do NOT want a Ford automotive regulator... it can cause an
>> overvoltage situation that even an external OV relay cannot overcome
>> (the automotive regulator sources regulator power directly from the
>> alternator, and thus ignores whether the OV relay or alternator half
>> of the master switch are providing power, or not.)
>>
>>>>
>>
>> I can't make sense of this, as long as we're talking about an
>> externally regulated alternator. Ford style regulators are flying in
>> thousands of homebuilts safely (assuming that OV protection is used).
>> As long as the wire to the field is interrupted, the alternator
>> cannot produce power. Typical OV protection circuits either open the
>> field lead or 'crowbar' it to ground, tripping the field circuit
>> breaker (which breaks the field circuit). Either way, there's no way
>> for the regulator to keep the alternator operating.
>>
>>
>
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Subject: | Re: Rotax ignition wiring |
Since there seem to be quite a few Rotax users on this forum, I have another question...
is it really necessary to separate the wiring coming from the engine
(pressure & temperature sensors, tachometer signal, etc). from the ignition wires
when penetrating the firewall. In other words, should the ignition wire have
their own penetration, separated from that other wiring? I believe this is
what Kitfox recommends. I hope this specific subject hasn't already been discussed
on this forum.
--------
John Evens
Thorp T-18 N71JE (built & flying)
Kitfox SS7 N27JE (building)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=450203#450203
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