Re: [time-nuts] USB over optical fiber

2019-12-10 Thread J. Cordaro via time-nuts 
 David,
I have used Pontis EMC USB converters and they worked meaning they had good 
radiated immunity and radiated emissions were below CISPR25 levels even in the 
150kHz - 30MHz band.  
hvtechnologies is the US distributor.

My first EMC certification test at low frequencies was a humbling experience 
due to the noise from the switching power supply.  At $7.50 per minute we went 
with stacks of AA batteries in parallel.  
regards,Jay Cordaro


On Friday, December 6, 2019, 03:48:18 PM PST, David Van Horn via time-nuts 
 wrote:  
 
 It's not shielded, and ferrites are pretty useless down here.
I did try, but the ferrites I have did nothing. 

My backup plan arrives supposedly in the next 2 hours

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: time-nuts  On Behalf Of Dana Whitlow
Sent: Friday, December 6, 2019 10:10 AM
To: Discussion of precise time and frequency measurement 

Subject: Re: [time-nuts] USB over optical fiber

Even without any funny business with boost converters (or whatever). those 
copper wires make a nice antenna for coupling noise from both ends (PC and USB
accessory) into
the environment inside the chamber.  Unless, of course, the cable is 
well-shielded, which you did not mention.

I suppose it's too late to ask, but did you perhance try adding some clamp-on 
ferrite chokes to the cable?

Dana


On Fri, Dec 6, 2019 at 10:05 AM David Van Horn via time-nuts < 
time-nuts@lists.febo.com> wrote:

> This is my backup plan:
> https://industrialcomponent.com/opticis/opm210003.html
>
> The docs are a bit chinglish, but I'm encouraged by the fact that the
> distal end needs external power.  I was hoping the corning one was
> powering the distal end by CW laser of maybe 200mW with data carried 
> on other wavelengths, or modulation of the power laser, but NOPE, just copper
> wires.  That one's packed up and ready to go back right now.
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345  x110
> email: david.vanh...@backcountryaccess.com
>
> -Original Message-
> From: Scott McGrath 
> Sent: Friday, December 6, 2019 6:29 AM
> To: David Van Horn 
> Cc: Discussion of precise time and frequency measurement < 
> time-nuts@lists.febo.com>
> Subject: Re: [time-nuts] USB over optical fiber
>
> Wow,  cost cutting at work I have the corning one but its 3 years old 
> Remember when FCC certification meant something for EMC
>
>
>
>
>
> > On Dec 6, 2019, at 3:21 PM, David Van Horn <
> david.vanh...@backcountryaccess.com> wrote:
> >
>
> Well, it arrived, and it is NOISY.  ☹ It's pushing out longitudinal 
> noise along the cable, and it's deafening my receiver.
>
> After doing some research this morning, it appears that they do the 
> DATA optically but power is taken on copper wires, and I'm betting a 
> boost switcher to compensate for the voltage drop in the 28 ga wire.
>
> https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf
>
>
>
> I have another candidate arriving today which will require a 5V supply 
> inside the cage, but I can do that with batteries and a linear 
> regulator, much quieter.
>
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345  x110
> email: david.vanh...@backcountryaccess.com
>
> -----Original Message-----
> From: time-nuts  On Behalf Of David 
> Van Horn via time-nuts
> Sent: Thursday, December 5, 2019 6:15 AM
> To: Scott McGrath ; Discussion of precise time 
> and frequency measurement 
> Cc: David Van Horn 
> Subject: Re: [time-nuts] USB over optical fiber
>
> Ok, thanks for the info.  My unit should be arriving today or tomorrow.
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345  x110
> email: david.vanh...@backcountryaccess.com
>
> -Original Message-
> From: Scott McGrath 
> Sent: Wednesday, December 4, 2019 9:16 PM
> To: Discussion of precise time and frequency measurement < 
> time-nuts@lists.febo.com>
> Cc: David Van Horn 
> Subject: Re: [time-nuts] USB over optical fiber
>
> You may still have a problem,  That said most of your noise power is 
> going to come from your USB device itself and perhaps the power supply
>
> That said ive never really had a problem doing similar testing using 
> small chambers from ET

Re: [time-nuts] USB over optical fiber

2019-12-06 Thread jimlux 

On 12/6/19 9:10 AM, Dana Whitlow wrote:

Even without any funny business with boost converters (or whatever). those
copper wires
make a nice antenna for coupling noise from both ends (PC and USB
accessory) into
the environment inside the chamber.  Unless, of course, the cable is
well-shielded, which
you did not mention.

I suppose it's too late to ask, but did you perhance try adding some
clamp-on ferrite chokes
to the cable?



We had a similar problem doing some testing on hardware in a EMI/EMC 
chamber where we wanted to measure fields well below the MIL-STD-461 
RE102 limits at HF frequencies.


Get some 31 mix toroids in the 2.4" diameter, and you can get a lot of 
turns of the cable through it and the hole is big enough to clear most 
connectors.  There are also clamp-on forms.  31 mix has a nice wide 
range, although I don't know if it goes down to 100kHz.. there might be 
a better mix.
You definitely don't want the usual VHF suppression mixes like 43 or 61. 
 But maybe mix 78, which is optimized for <2MHz


In this kind of application you want to look at mu'' (the lossy part of 
permeability) as well as mu' (the non lossy part)


Or, as you plan to do, run stuff off batteries.



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Re: [time-nuts] USB over optical fiber

2019-12-06 Thread David Van Horn via time-nuts 
It's not shielded, and ferrites are pretty useless down here.
I did try, but the ferrites I have did nothing. 

My backup plan arrives supposedly in the next 2 hours

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: time-nuts  On Behalf Of Dana Whitlow
Sent: Friday, December 6, 2019 10:10 AM
To: Discussion of precise time and frequency measurement 

Subject: Re: [time-nuts] USB over optical fiber

Even without any funny business with boost converters (or whatever). those 
copper wires make a nice antenna for coupling noise from both ends (PC and USB
accessory) into
the environment inside the chamber.  Unless, of course, the cable is 
well-shielded, which you did not mention.

I suppose it's too late to ask, but did you perhance try adding some clamp-on 
ferrite chokes to the cable?

Dana


On Fri, Dec 6, 2019 at 10:05 AM David Van Horn via time-nuts < 
time-nuts@lists.febo.com> wrote:

> This is my backup plan:
> https://industrialcomponent.com/opticis/opm210003.html
>
> The docs are a bit chinglish, but I'm encouraged by the fact that the
> distal end needs external power.   I was hoping the corning one was
> powering the distal end by CW laser of maybe 200mW with data carried 
> on other wavelengths, or modulation of the power laser, but NOPE, just copper
> wires.   That one's packed up and ready to go back right now.
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345  x110
> email: david.vanh...@backcountryaccess.com
>
> -Original Message-
> From: Scott McGrath 
> Sent: Friday, December 6, 2019 6:29 AM
> To: David Van Horn 
> Cc: Discussion of precise time and frequency measurement < 
> time-nuts@lists.febo.com>
> Subject: Re: [time-nuts] USB over optical fiber
>
> Wow,  cost cutting at work I have the corning one but its 3 years old 
> Remember when FCC certification meant something for EMC
>
>
>
>
>
> > On Dec 6, 2019, at 3:21 PM, David Van Horn <
> david.vanh...@backcountryaccess.com> wrote:
> >
>
> Well, it arrived, and it is NOISY.  ☹ It's pushing out longitudinal 
> noise along the cable, and it's deafening my receiver.
>
> After doing some research this morning, it appears that they do the 
> DATA optically but power is taken on copper wires, and I'm betting a 
> boost switcher to compensate for the voltage drop in the 28 ga wire.
>
> https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf
>
>
>
> I have another candidate arriving today which will require a 5V supply 
> inside the cage, but I can do that with batteries and a linear 
> regulator, much quieter.
>
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345  x110
> email: david.vanh...@backcountryaccess.com
>
> -----Original Message-----
> From: time-nuts  On Behalf Of David 
> Van Horn via time-nuts
> Sent: Thursday, December 5, 2019 6:15 AM
> To: Scott McGrath ; Discussion of precise time 
> and frequency measurement 
> Cc: David Van Horn 
> Subject: Re: [time-nuts] USB over optical fiber
>
> Ok, thanks for the info.  My unit should be arriving today or tomorrow.
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345  x110
> email: david.vanh...@backcountryaccess.com
>
> -Original Message-
> From: Scott McGrath 
> Sent: Wednesday, December 4, 2019 9:16 PM
> To: Discussion of precise time and frequency measurement < 
> time-nuts@lists.febo.com>
> Cc: David Van Horn 
> Subject: Re: [time-nuts] USB over optical fiber
>
> You may still have a problem,  That said most of your noise power is 
> going to come from your USB device itself and perhaps the power supply
>
> That said ive never really had a problem doing similar testing using 
> small chambers from ETS-Lindgren and similar vendors using the Corning 
> interface.
>
> That said i’d recommend you go a step up to the Newnex and similar 
> devices they are 3x the price but the fiber interlink is just a 
> standard fiber LC-LC patch cord.
>
> With the low cost interface crimp its cable once accidentally you are 
> buying a new one.
>
> With the newnex you are buying a 20-30 dollar patch cord.
>
> All that said performance is the same in the end but the newnex and
> similar have an advantage in an o

Re: [time-nuts] USB over optical fiber

2019-12-06 Thread Dana Whitlow 
Even without any funny business with boost converters (or whatever). those
copper wires
make a nice antenna for coupling noise from both ends (PC and USB
accessory) into
the environment inside the chamber.  Unless, of course, the cable is
well-shielded, which
you did not mention.

I suppose it's too late to ask, but did you perhance try adding some
clamp-on ferrite chokes
to the cable?

Dana


On Fri, Dec 6, 2019 at 10:05 AM David Van Horn via time-nuts <
time-nuts@lists.febo.com> wrote:

> This is my backup plan:
> https://industrialcomponent.com/opticis/opm210003.html
>
> The docs are a bit chinglish, but I'm encouraged by the fact that the
> distal end needs external power.   I was hoping the corning one was
> powering the distal end by CW laser of maybe 200mW with data carried on
> other wavelengths, or modulation of the power laser, but NOPE, just copper
> wires.   That one's packed up and ready to go back right now.
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345  x110
> email: david.vanh...@backcountryaccess.com
>
> -Original Message-
> From: Scott McGrath 
> Sent: Friday, December 6, 2019 6:29 AM
> To: David Van Horn 
> Cc: Discussion of precise time and frequency measurement <
> time-nuts@lists.febo.com>
> Subject: Re: [time-nuts] USB over optical fiber
>
> Wow,  cost cutting at work I have the corning one but its 3 years old
> Remember when FCC certification meant something for EMC
>
>
>
>
>
> > On Dec 6, 2019, at 3:21 PM, David Van Horn <
> david.vanh...@backcountryaccess.com> wrote:
> >
>
> Well, it arrived, and it is NOISY.  ☹
> It's pushing out longitudinal noise along the cable, and it's deafening my
> receiver.
>
> After doing some research this morning, it appears that they do the DATA
> optically but power is taken on copper wires, and I'm betting a boost
> switcher to compensate for the voltage drop in the 28 ga wire.
>
> https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf
>
>
>
> I have another candidate arriving today which will require a 5V supply
> inside the cage, but I can do that with batteries and a linear regulator,
> much quieter.
>
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345  x110
> email: david.vanh...@backcountryaccess.com
>
> -----Original Message-----
> From: time-nuts  On Behalf Of David Van
> Horn via time-nuts
> Sent: Thursday, December 5, 2019 6:15 AM
> To: Scott McGrath ; Discussion of precise time and
> frequency measurement 
> Cc: David Van Horn 
> Subject: Re: [time-nuts] USB over optical fiber
>
> Ok, thanks for the info.  My unit should be arriving today or tomorrow.
>
> --
> David VanHorn
> Lead Hardware Engineer
>
> Backcountry Access, Inc.
> 2820 Wilderness Pl, Unit H
> Boulder, CO  80301 USA
> phone: 303-417-1345  x110
> email: david.vanh...@backcountryaccess.com
>
> -Original Message-
> From: Scott McGrath 
> Sent: Wednesday, December 4, 2019 9:16 PM
> To: Discussion of precise time and frequency measurement <
> time-nuts@lists.febo.com>
> Cc: David Van Horn 
> Subject: Re: [time-nuts] USB over optical fiber
>
> You may still have a problem,  That said most of your noise power is going
> to come from your USB device itself and perhaps the power supply
>
> That said ive never really had a problem doing similar testing using small
> chambers from ETS-Lindgren and similar vendors using the Corning
> interface.
>
> That said i’d recommend you go a step up to the Newnex and similar devices
> they are 3x the price but the fiber interlink is just a standard fiber
> LC-LC patch cord.
>
> With the low cost interface crimp its cable once accidentally you are
> buying a new one.
>
> With the newnex you are buying a 20-30 dollar patch cord.
>
> All that said performance is the same in the end but the newnex and
> similar have an advantage in an open lab.   For permanent installation in
> raceway the cost advantage is with the one piece units.
>
> Content by Scott
> Typos by Siri
>
> > On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts <
> time-nuts@lists.febo.com> wrote:
> >
>
> I'm not too worried up there, my receivers are working at 457 kHz.
>
> -Original Message-
> From: Scott McGrath 
> Sent: Wednesday, December 4, 2019 12:14 AM
> To: Discussion of precise time and frequency measurement <
> time-nuts@lists.febo.com>
> Cc: David Van Horn 
>

Re: [time-nuts] USB over optical fiber

2019-12-06 Thread David Van Horn via time-nuts 
This is my backup plan:
https://industrialcomponent.com/opticis/opm210003.html

The docs are a bit chinglish, but I'm encouraged by the fact that the distal 
end needs external power.   I was hoping the corning one was powering the 
distal end by CW laser of maybe 200mW with data carried on other wavelengths, 
or modulation of the power laser, but NOPE, just copper wires.   That one's 
packed up and ready to go back right now.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: Scott McGrath  
Sent: Friday, December 6, 2019 6:29 AM
To: David Van Horn 
Cc: Discussion of precise time and frequency measurement 

Subject: Re: [time-nuts] USB over optical fiber

Wow,  cost cutting at work I have the corning one but its 3 years old Remember 
when FCC certification meant something for EMC 





> On Dec 6, 2019, at 3:21 PM, David Van Horn 
>  wrote:
> 

Well, it arrived, and it is NOISY.  ☹
It's pushing out longitudinal noise along the cable, and it's deafening my 
receiver.

After doing some research this morning, it appears that they do the DATA 
optically but power is taken on copper wires, and I'm betting a boost switcher 
to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf



I have another candidate arriving today which will require a 5V supply inside 
the cage, but I can do that with batteries and a linear regulator, much quieter.


--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: time-nuts  On Behalf Of David Van Horn 
via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath ; Discussion of precise time and 
frequency measurement 
Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: Scott McGrath 
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to 
come from your USB device itself and perhaps the power supply 

That said ive never really had a problem doing similar testing using small 
chambers from ETS-Lindgren and similar vendors using the Corning interface. 

That said i’d recommend you go a step up to the Newnex and similar devices they 
are 3x the price but the fiber interlink is just a standard fiber LC-LC patch 
cord.

With the low cost interface crimp its cable once accidentally you are buying a 
new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar 
have an advantage in an open lab.   For permanent installation in raceway the 
cost advantage is with the one piece units.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts 
>  wrote:
> 

I'm not too worried up there, my receivers are working at 457 kHz. 

-Original Message-
From: Scott McGrath 
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d 
worry about as USB 3.0 generates RF signals up to 3 GHz.   And also has fairly 
strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts 
>  wrote:
> 

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices 
($200-300) are acceptable, but I’m worried about noise that the downstream end 
may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com<mailto:david.vanh...@backcountryaccess.com>

___
time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to 
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and follow the instructions there.

Re: [time-nuts] USB over optical fiber

2019-12-06 Thread David Van Horn via time-nuts 
Well, it arrived, and it is NOISY.  ☹
It's pushing out longitudinal noise along the cable, and it's deafening my 
receiver.

After doing some research this morning, it appears that they do the DATA 
optically but power is taken on copper wires, and I'm betting a boost switcher 
to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf



I have another candidate arriving today which will require a 5V supply inside 
the cage, but I can do that with batteries and a linear regulator, much quieter.


--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: time-nuts  On Behalf Of David Van Horn 
via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath ; Discussion of precise time and 
frequency measurement 
Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: Scott McGrath 
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to 
come from your USB device itself and perhaps the power supply 

That said ive never really had a problem doing similar testing using small 
chambers from ETS-Lindgren and similar vendors using the Corning interface. 

That said i’d recommend you go a step up to the Newnex and similar devices they 
are 3x the price but the fiber interlink is just a standard fiber LC-LC patch 
cord.

With the low cost interface crimp its cable once accidentally you are buying a 
new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar 
have an advantage in an open lab.   For permanent installation in raceway the 
cost advantage is with the one piece units.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts 
>  wrote:
> 

I'm not too worried up there, my receivers are working at 457 kHz. 

-Original Message-
From: Scott McGrath 
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d 
worry about as USB 3.0 generates RF signals up to 3 GHz.   And also has fairly 
strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts 
>  wrote:
> 

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices 
($200-300) are acceptable, but I’m worried about noise that the downstream end 
may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com<mailto:david.vanh...@backcountryaccess.com>

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Re: [time-nuts] USB over optical fiber

2019-12-06 Thread David Van Horn via time-nuts 
It might pass class A or even B, but it totally obliterates the signals I'm 
looking for down at 457kHz.  The noise is pumped longitudinally along the 
"optical cable" and the metallic one to the product, which pretty much confirms 
a boost or flyback regulator making up for the voltage drop in the long thin 
wires.

Fortunately I have another one arriving today which does NOT have metallic 
conductors in the cable.  I'll need 5V to power the downstream end, but I can 
do that with D cells and an LDO if I have to.  Can't get much more quiet than 
that.



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: Scott McGrath  
Sent: Friday, December 6, 2019 6:29 AM
To: David Van Horn 
Cc: Discussion of precise time and frequency measurement 

Subject: Re: [time-nuts] USB over optical fiber

Wow,  cost cutting at work I have the corning one but its 3 years old Remember 
when FCC certification meant something for EMC 





> On Dec 6, 2019, at 3:21 PM, David Van Horn 
>  wrote:
> 

Well, it arrived, and it is NOISY.  ☹
It's pushing out longitudinal noise along the cable, and it's deafening my 
receiver.

After doing some research this morning, it appears that they do the DATA 
optically but power is taken on copper wires, and I'm betting a boost switcher 
to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf



I have another candidate arriving today which will require a 5V supply inside 
the cage, but I can do that with batteries and a linear regulator, much quieter.


--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: time-nuts  On Behalf Of David Van Horn 
via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath ; Discussion of precise time and 
frequency measurement 
Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: Scott McGrath 
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to 
come from your USB device itself and perhaps the power supply 

That said ive never really had a problem doing similar testing using small 
chambers from ETS-Lindgren and similar vendors using the Corning interface. 

That said i’d recommend you go a step up to the Newnex and similar devices they 
are 3x the price but the fiber interlink is just a standard fiber LC-LC patch 
cord.

With the low cost interface crimp its cable once accidentally you are buying a 
new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar 
have an advantage in an open lab.   For permanent installation in raceway the 
cost advantage is with the one piece units.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts 
>  wrote:
> 

I'm not too worried up there, my receivers are working at 457 kHz. 

-Original Message-
From: Scott McGrath 
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d 
worry about as USB 3.0 generates RF signals up to 3 GHz.   And also has fairly 
strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts 
>  wrote:
> 

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices 
($200-300) are acceptable, but I’m worried about noise that the downstream end 
may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com<mailto:david.vanh...@backcountryaccess.com>

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Re: [time-nuts] USB over optical fiber

2019-12-06 Thread Scott McGrath 
Wow,  cost cutting at work I have the corning one but its 3 years old Remember 
when FCC certification meant something for EMC 





> On Dec 6, 2019, at 3:21 PM, David Van Horn 
>  wrote:
> 

Well, it arrived, and it is NOISY.  ☹
It's pushing out longitudinal noise along the cable, and it's deafening my 
receiver.

After doing some research this morning, it appears that they do the DATA 
optically but power is taken on copper wires, and I'm betting a boost switcher 
to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf



I have another candidate arriving today which will require a 5V supply inside 
the cage, but I can do that with batteries and a linear regulator, much quieter.


--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: time-nuts  On Behalf Of David Van Horn 
via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath ; Discussion of precise time and 
frequency measurement 
Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: Scott McGrath 
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to 
come from your USB device itself and perhaps the power supply 

That said ive never really had a problem doing similar testing using small 
chambers from ETS-Lindgren and similar vendors using the Corning interface. 

That said i’d recommend you go a step up to the Newnex and similar devices they 
are 3x the price but the fiber interlink is just a standard fiber LC-LC patch 
cord.

With the low cost interface crimp its cable once accidentally you are buying a 
new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar 
have an advantage in an open lab.   For permanent installation in raceway the 
cost advantage is with the one piece units.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts 
>  wrote:
> 

I'm not too worried up there, my receivers are working at 457 kHz. 

-Original Message-
From: Scott McGrath 
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d 
worry about as USB 3.0 generates RF signals up to 3 GHz.   And also has fairly 
strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts 
>  wrote:
> 

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices 
($200-300) are acceptable, but I’m worried about noise that the downstream end 
may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com<mailto:david.vanh...@backcountryaccess.com>

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Re: [time-nuts] USB over optical fiber

2019-12-05 Thread David Van Horn via time-nuts 
Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanh...@backcountryaccess.com 

-Original Message-
From: Scott McGrath  
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to 
come from your USB device itself and perhaps the power supply 

That said ive never really had a problem doing similar testing using small 
chambers from ETS-Lindgren and similar vendors using the Corning interface. 

That said i’d recommend you go a step up to the Newnex and similar devices they 
are 3x the price but the fiber interlink is just a standard fiber LC-LC patch 
cord.

With the low cost interface crimp its cable once accidentally you are buying a 
new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar 
have an advantage in an open lab.   For permanent installation in raceway the 
cost advantage is with the one piece units.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts 
>  wrote:
> 

I'm not too worried up there, my receivers are working at 457 kHz. 

-Original Message-
From: Scott McGrath 
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d 
worry about as USB 3.0 generates RF signals up to 3 GHz.   And also has fairly 
strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts 
>  wrote:
> 

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices 
($200-300) are acceptable, but I’m worried about noise that the downstream end 
may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com<mailto:david.vanh...@backcountryaccess.com>

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Re: [time-nuts] USB over optical fiber

2019-12-04 Thread Scott McGrath 
You may still have a problem,  That said most of your noise power is going to 
come from your USB device itself and perhaps the power supply 

That said ive never really had a problem doing similar testing using small 
chambers from ETS-Lindgren and similar vendors using the Corning interface. 

That said i’d recommend you go a step up to the Newnex and similar devices they 
are 3x the price but the fiber interlink is just a standard fiber LC-LC patch 
cord.

With the low cost interface crimp its cable once accidentally you are buying a 
new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar 
have an advantage in an open lab.   For permanent installation in raceway the 
cost advantage is with the one piece units.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts 
>  wrote:
> 

I'm not too worried up there, my receivers are working at 457 kHz. 

-Original Message-
From: Scott McGrath  
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d 
worry about as USB 3.0 generates RF signals up to 3 GHz.   And also has fairly 
strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts 
>  wrote:
> 

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices 
($200-300) are acceptable, but I’m worried about noise that the downstream end 
may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com<mailto:david.vanh...@backcountryaccess.com>

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Re: [time-nuts] USB over optical fiber

2019-12-04 Thread David Van Horn via time-nuts 
I'm not too worried up there, my receivers are working at 457 kHz. 

-Original Message-
From: Scott McGrath  
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement 

Cc: David Van Horn 
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d 
worry about as USB 3.0 generates RF signals up to 3 GHz.   And also has fairly 
strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts 
>  wrote:
> 

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices 
($200-300) are acceptable, but I’m worried about noise that the downstream end 
may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com<mailto:david.vanh...@backcountryaccess.com>

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Re: [time-nuts] USB over optical fiber

2019-12-04 Thread Scott McGrath 
Its not so much the noise from the interface its the USB device itself i’d 
worry about as USB 3.0 generates RF signals up to 3 GHz.   And also has fairly 
strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

> On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts 
>  wrote:
> 

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices 
($200-300) are acceptable, but I’m worried about noise that the downstream end 
may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com

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[time-nuts] USB over optical fiber

2019-12-03 Thread David Van Horn via time-nuts 
I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices 
($200-300) are acceptable, but I’m worried about noise that the downstream end 
may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?



--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: 
david.vanh...@backcountryaccess.com

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