Re: [time-nuts] Z3801A going into Holdover

[Mike Seguin]

I have a weird one with my Z3801A. Screen shot from GPSCon attached. You 
can see the EFC excursion... Maybe the oven in the OCXO is acting up???


Mike

On 6/20/2019 10:25 PM, Mark Sims wrote:

A few months ago, my 3801A started doing this.   It was tracking sats well 
(several years ago I had to replace the receiver because it had lots of 
problems acquiring and tracking sats).I swapped in a replacement 10811 OCXO 
and that fixed the problem.

Apparently the problem with the receiver not tracking sats is usually due to 
the oscillator on the receiver drifting out of spec.  Some of them have an 
adjustment screw...
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--

73,
Mike, N1JEZ
"A closed mouth gathers no feet"
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Re: [time-nuts] Z3801A going into Holdover

[Bob kb8tq]

Hi

Which is why I asked about the EFC ….. they *should* start complaining when the 
EFC gets close to limit. 
How close? No idea. Are there other parameters it monitors? No idea. 

The (useless) heater box around the 10811 in the Z3801 can be opened up. Inside 
is a fairly normal 10811. On the ones
I have seen, there is a trimmer in the usual location. The gotcha is that with 
the “extended” EFC range on the
unit, it has drifted a *long* way by the time it fails. The trimmer may get it 
back, it may also not really have 
enough range to do what you need to do.

Bob

> On Jun 20, 2019, at 10:25 PM, Mark Sims  wrote:
> 
> A few months ago, my 3801A started doing this.   It was tracking sats well 
> (several years ago I had to replace the receiver because it had lots of 
> problems acquiring and tracking sats).I swapped in a replacement 10811 
> OCXO and that fixed the problem.
> 
> Apparently the problem with the receiver not tracking sats is usually due to 
> the oscillator on the receiver drifting out of spec.  Some of them have an 
> adjustment screw...
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Re: [time-nuts] Z3801A going into Holdover

[Dan Rae via time-nuts]

Thanks to all who offered advice.  I have attached a LH screen shot 
showing last night's event.  From my limited understanding it looks like 
the receiver part is working fine...  The EFC had started to dive 
however, more than two hours before it went into holdover.


I'd appreciate comments from those who do understand :^)

Dan

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[time-nuts] GPSDO 10MHZ Splitter

[Don Meadows]

Is there an easy, and cheap way to add a splitter the 10Mhz signal 
from GPSDO, without going to a distribution amplifier to
feed two different devices?

I really don’t want to build a complicated project, or 
spend $200.00 dollars for an 8 output distribution amp
off the net.  One output would be dedicated for my
 counter time base, and the other would be an ‘extra’ 
10MHZ source for another counter, or just to display on the scope.

I don’t have a GPSDO yet, I just can’t decide on one.
I am leaning to the Trimble, but it’s still undecided.

Could anyone comment on buying a “Refurbished by Seller”
GPSDO on E-bay. They are a few dollars cheaper, but I really
want one I can have trust and confidence in.

Sorry for the long post.
Thanks, Don



Sent from Mail for Windows 10

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Re: [time-nuts] Z3801A going into Holdover

[paul swed]

I appreciate the response on the outer oven. When it goes bad it makes a
heck of a mess.
If its not needed it would be good to turn off. Not to distract from this
important subject. Is there a way to disable the oven and yet make the 3801
think its at temperature. (May not actually feed back to anything to give
status) Maybe it can just be disconnected.
Thank you.
Paul.

On Fri, Jun 21, 2019 at 10:00 AM Dan Rae via time-nuts <
time-nuts@lists.febo.com> wrote:

>
> Thanks to all who offered advice.  I have attached a LH screen shot
> showing last night's event.  From my limited understanding it looks like
> the receiver part is working fine...  The EFC had started to dive
> however, more than two hours before it went into holdover.
>
> I'd appreciate comments from those who do understand :^)
>
> Dan
>
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Re: [time-nuts] GPSDO 10MHZ Splitter

[jimlux]

On 6/21/19 7:27 AM, Don Meadows wrote:

Is there an easy, and cheap way to add a splitter the 10Mhz signal
from GPSDO, without going to a distribution amplifier to
feed two different devices?


Just a power divider, or a BNC T, - it's not perfect, but it works.
there's isolation and potential mismatch/reflections, so if you're 
measuring 1E-16 ADEV, maybe not the best approach.


But there's an awful lot of people who just hook up a bunch of test 
equipment with BNC Ts.  Some equipment actually has a switch to 
configure whether the 10MHz input is high Z or 50 ohms.


For "display on the scope" you're going into a high Z input (1 Meg) - so 
the BNC T approach will work fine.


Just be aware that if you pick a coax length that is "wrong" you'll make 
a dandy 10 MHz notch filter. (10 MHz is 30 meters in free space, about 
20 meters in coax, so a 1/4 wavelength is about 5 meters.. )


If you go

GPSDO
cable
BNC T on scope High Z
cable
Counter

Then you don't have problems.

If you go

GPSDO
BNC T - 5 meter cable - Scope High Z
cable
Counter

or
GPSDO
cable
BNC T on counter - 5 meter cable - Scope High Z





I really don’t want to build a complicated project, or
spend $200.00 dollars for an 8 output distribution amp
off the net.  One output would be dedicated for my
  counter time base, and the other would be an ‘extra’
10MHZ source for another counter, or just to display on the scope.

I don’t have a GPSDO yet, I just can’t decide on one.
I am leaning to the Trimble, but it’s still undecided.

Could anyone comment on buying a “Refurbished by Seller”
GPSDO on E-bay. They are a few dollars cheaper, but I really
want one I can have trust and confidence in.

Sorry for the long post.
Thanks, Don



Sent from Mail for Windows 10

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Re: [time-nuts] GPSDO 10MHZ Splitter

[W7SLS]

A couple of ideas:

Make one:

Several hours and a few $  (cheap if you value your time as free)
agree, not a lot of isolation between the outputs
Case, connector, and three 16.67 ohm resistors
in —> 16.67 ohms —> 16.67 ohms to output 1
   —> 16.67 ohms to output 2

Ref:  
https://www.markimicrowave.com/blog/how-to-make-an-n-way-power-splitter/

Perhaps free (may or may not work):

Television 75 ohm splitter
agree, mismatch between 75 ohms and 50 ohms
agree, ugh to F connectors

Ref: I don’t know if this just occurred to me, or if I read it (e.g., 
on this group)

Buy one:

Example: Mini-Circuits ZSC-2-1+, about $50 new
https://www.minicircuits.com/WebStore/dashboard.html?model=ZSC-2-1%2B 


Gulp:

Your mileage may vary
BNC-T connector

As mentioned elsewhere:

Legacy RGB distribution boxes (e.g. Extron), about $40 on auction sites
Yes, they are 75 ohms, but may be fine, or you can change the internal 
resistors to move to 50 ohms.

And of course there are other ($$$) solutions.

(Obviously) I defer to the wisdom of the group (and perhaps groans and eye 
rolls).

Best of luck, whatever you choose.

Scott
W7SLS




> On Jun 21, 2019, at 7:27 AM, Don Meadows  wrote:
> 
> Is there an easy, and cheap way to add a splitter the 10Mhz signal 
> from GPSDO, without going to a distribution amplifier to
> feed two different devices?
> 
> I really don’t want to build a complicated project, or 
> spend $200.00 dollars for an 8 output distribution amp
> off the net.  One output would be dedicated for my
> counter time base, and the other would be an ‘extra’ 
> 10MHZ source for another counter, or just to display on the scope.
> 
> I don’t have a GPSDO yet, I just can’t decide on one.
> I am leaning to the Trimble, but it’s still undecided.
> 
> Could anyone comment on buying a “Refurbished by Seller”
> GPSDO on E-bay. They are a few dollars cheaper, but I really
> want one I can have trust and confidence in.
> 
> Sorry for the long post.
> Thanks, Don
> 
> 
> 
> Sent from Mail for Windows 10
> 
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Re: [time-nuts] GPSDO 10MHZ Splitter

[Bob Bownes]

Sure, presuming the output is 50Ω, build a 50Ω power divider. The signal
will be 3dB down on each of the outgoing legs vs the input. Plenty of
designs if you google it.

If the output is TTL, feed a 74xx04 on pin 1, send pin 2 to 3 and 5, pick
up the output from 4 and 6. Or choose some other gate you have handy.

Bob


On Fri, Jun 21, 2019 at 12:07 PM Don Meadows  wrote:

> Is there an easy, and cheap way to add a splitter the 10Mhz signal
> from GPSDO, without going to a distribution amplifier to
> feed two different devices?
>
> I really don’t want to build a complicated project, or
> spend $200.00 dollars for an 8 output distribution amp
> off the net.  One output would be dedicated for my
>  counter time base, and the other would be an ‘extra’
> 10MHZ source for another counter, or just to display on the scope.
>
> I don’t have a GPSDO yet, I just can’t decide on one.
> I am leaning to the Trimble, but it’s still undecided.
>
> Could anyone comment on buying a “Refurbished by Seller”
> GPSDO on E-bay. They are a few dollars cheaper, but I really
> want one I can have trust and confidence in.
>
> Sorry for the long post.
> Thanks, Don
>
>
>
> Sent from Mail for Windows 10
>
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Re: [time-nuts] GPSDO 10MHZ Splitter

[Jwahar Bammi via time-nuts]

Don,
I use a video distribution amplifier. Bought one off eBay for around $12 or so  
about 2 years agio, model is Sigma  VDA 100A, i am sure there are many suitable 
models on eBay.

cheers,
bammi
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Re: [time-nuts] GPSDO 10MHZ Splitter

[ew via time-nuts]

There is a Trimbo GPSDO on ebay. We have a couple. 252162780444    look to me  
a later version of the Tbolt, has an additional board with Power and 
amplifiers. One 10 MHz is TTL and the other sine wave. Use the TTL for the 
counter.There is an other one on Auction, looks identical has two outputs but 
says Smmetricon may be cheaper 264367965036Bert Kehren

Seller assumes all responsibility for this listing.
In a message dated 6/21/2019 12:07:27 PM Eastern Standard Time, 
donmeadow...@gmail.com writes:

Is there an easy, and cheap way to add a splitter the 10Mhz signal from GPSDO, 
without going to a distribution amplifier tofeed two different devices?
I really don’t want to build a complicated project, or spend $200.00 dollars 
for an 8 output distribution ampoff the net.  One output would be dedicated for 
mycounter time base, and the other would be an ‘extra’ 10MHZ source for another 
counter, or just to display on the scope.
I don’t have a GPSDO yet, I just can’t decide on one.I am leaning to the 
Trimble, but it’s still undecided.
Could anyone comment on buying a “Refurbished by Seller”GPSDO on E-bay. They 
are a few dollars cheaper, but I reallywant one I can have trust and confidence 
in.
Sorry for the long post.Thanks, Don


Sent from Mail for Windows 10
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Re: [time-nuts] Z3801A going into Holdover

[Tom Van Baak]

Dan,

I hate to speculate but it's really odd that more than one person is 
reporting EFC issues with the Z3801A this week. I wonder if it's a bug 
in the Motorola Oncore; the OEM GPS receiver used in the Z3801A (and 
other early hp GPSDO). Two events have happened recently:


1) There was a GPS WNRO in April 2019, so Oncore dates will be wrong. 
But, like the rollover in August 1999, this shouldn't cause a GPSDO to 
go crazy.


2) More interesting, as of June 16, it's been 128 weeks since the 
previous leap second. There were reports of some aircraft GPS receivers 
losing lock from June 9 to June 16 due to an obscure bug in certain GPS 
receivers. It's related to leap seconds and 8-bit week numbers (127 + 1 
is -1 not 128).


In theory this shouldn't cause a GPSDO any trouble, but I know that a 
vaguely similar 8-bit problem occurred with the Oncore VP back in 2003. See:


http://leapsecond.com/notes/leapsec256.htm

If anyone happens to have a binary log from an Oncore VP or UT for the 
past week or two, please let me know.


Thanks,
/tvb


On 6/20/2019 10:05 AM, Dan Rae via time-nuts wrote:
I have an elderly 3801A with some 182,000 hours on the clock, which if 
my arithmetic is correct means over twenty years of operation.  Since 
it has a well aged and remarkably stable OCXO I would like to keep it 
going if possible.  Recently it has been going into Holdover and 
staying there for no reason that I can see, it is fed from the same 
antenna / splitter amp combination with a good sky view as eight other 
GPSDOs here.  LH reports as good a signal strength on it as any of the 
others.  A Cold Reset gets it going again.


Does anyone know if a more modern receiver can be fitted in place of 
the existing VP6?  Is it likely to be a Rx problem anyway?


I'm running LH at the moment and will try to capture a screen when it 
next goes into Holdover to see if that gives me any clues.


Thanks for any advice!

Dan




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Re: [time-nuts] GPSDO 10MHZ Splitter

[Bob kb8tq]

Hi

Cheapest and easiest is to use a power splitter. Ones from Mini Circuits that 
are
rated to work at 10 MHz can be had for $20 or less. At some point you run out
of power ….

Building a splitter from NC7SZ125’s is not a all that crazy as a DIY project. 
You 
can get a dozen or so outputs and still not spend twice what the eBay splitter 
would have cost you. Cost is a bit less if you are happy with TTL out as opposed
to sine waves. ( = you don’t have to spend money on the coils for the T 
networks 
in the output lines). 

Either way, the signal is pretty well isolated and as clean as it was coming 
out of the 
GPSDO. 

Bob

> On Jun 21, 2019, at 10:27 AM, Don Meadows  wrote:
> 
> Is there an easy, and cheap way to add a splitter the 10Mhz signal 
> from GPSDO, without going to a distribution amplifier to
> feed two different devices?
> 
> I really don’t want to build a complicated project, or 
> spend $200.00 dollars for an 8 output distribution amp
> off the net.  One output would be dedicated for my
> counter time base, and the other would be an ‘extra’ 
> 10MHZ source for another counter, or just to display on the scope.
> 
> I don’t have a GPSDO yet, I just can’t decide on one.
> I am leaning to the Trimble, but it’s still undecided.
> 
> Could anyone comment on buying a “Refurbished by Seller”
> GPSDO on E-bay. They are a few dollars cheaper, but I really
> want one I can have trust and confidence in.
> 
> Sorry for the long post.
> Thanks, Don
> 
> 
> 
> Sent from Mail for Windows 10
> 
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Re: [time-nuts] GPSDO 10MHZ Splitter

[Sam Sjogren]

If you don't need them to be in phase, you could just daisy chain them.
What I do is use a couple of BNC tee connectors, two pieces of coax, and a
50 ohm terminator on the last tee. First coax from GPSDO to first tee,
second coax between tees.  Simple and works fine for my purposes.

If phase is important, then put one tee on the GPSDO output then feed the
instruments from there with two identical pieces of coax with a terminator
at each instrument (if they don't have 50 ohm inputs to begin with).

You should verify, perhaps with a scope, that the signals look good at each
instrument.  One of my GPSDOs even has a tunable driving parameter so I can
ensure the amplitudes are in spec; could be handy for the in-phase
configuration where the extra terminator may load the signal down a bit
much.

>Is there an easy, and cheap way to add a splitter the 10Mhz signal
>from GPSDO, without going to a distribution amplifier to
>feed two different devices?

-- 
73,
-Sam
 WB6RJH
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[time-nuts] Cloudflare

[Marco Davids via time-nuts]

Opinions, anyone?

https://blog.cloudflare.com/secure-time/amp/

("Introducing time.cloudflare.com")

--
Marco



signature.asc
Description: OpenPGP digital signature
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Re: [time-nuts] GPSDO 10MHZ Splitter

[Clay Autery]

Easy, Cheap, Good choose 2.

I looked at virtually every option  I love to build.  I settled on 
HP 8-way and 4-way unity gain splitters WITH external power supply 
ports.  I actually retrofitted one with the very hard to find connector.
Easier to find it now...  Well worth the cost to get a small, sealed, 
metal enclosure, with really nice AND equal ports... And I can control 
the power input, and all the ports have no DC superimposed.


There are more expensive and better designs I am sure, but I really dig 
these...  they way exceed my requirements and I NEVER have to worry 
about them being THE issue if there is AN issue.


YMMV...

73,

__
Clay Autery, KY5G
(318) 518-1389

On 21-Jun-19 12:08, jimlux wrote:

On 6/21/19 7:27 AM, Don Meadows wrote:

Is there an easy, and cheap way to add a splitter the 10Mhz signal
from GPSDO, without going to a distribution amplifier to
feed two different devices?


Just a power divider, or a BNC T, - it's not perfect, but it works.
there's isolation and potential mismatch/reflections, so if you're 
measuring 1E-16 ADEV, maybe not the best approach.


But there's an awful lot of people who just hook up a bunch of test 
equipment with BNC Ts.  Some equipment actually has a switch to 
configure whether the 10MHz input is high Z or 50 ohms.


For "display on the scope" you're going into a high Z input (1 Meg) - 
so the BNC T approach will work fine.


Just be aware that if you pick a coax length that is "wrong" you'll 
make a dandy 10 MHz notch filter. (10 MHz is 30 meters in free space, 
about 20 meters in coax, so a 1/4 wavelength is about 5 meters.. )


If you go

GPSDO
cable
BNC T on scope High Z
cable
Counter

Then you don't have problems.

If you go

GPSDO
BNC T - 5 meter cable - Scope High Z
cable
Counter

or
GPSDO
cable
BNC T on counter - 5 meter cable - Scope High Z





I really don’t want to build a complicated project, or
spend $200.00 dollars for an 8 output distribution amp
off the net.  One output would be dedicated for my
  counter time base, and the other would be an ‘extra’
10MHZ source for another counter, or just to display on the scope.

I don’t have a GPSDO yet, I just can’t decide on one.
I am leaning to the Trimble, but it’s still undecided.

Could anyone comment on buying a “Refurbished by Seller”
GPSDO on E-bay. They are a few dollars cheaper, but I really
want one I can have trust and confidence in.

Sorry for the long post.
Thanks, Don



Sent from Mail for Windows 10

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Re: [time-nuts] Cloudflare

[Aanchal Malhotra]

On Fri, Jun 21, 2019 at 4:03 PM Marco Davids via time-nuts <
time-nuts@lists.febo.com> wrote:

> Opinions, anyone?
>
> https://blog.cloudflare.com/secure-time/amp/
>
> ("Introducing time.cloudflare.com")
>

Would love to have the feedback :)

>
> --
> Marco
>
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Re: [time-nuts] Cloudflare

[Bob kb8tq]

Hi

Given the relatively low cost of a GPS based “Stratum 1” NTP, it’s not real 
clear 
why (at the end of the paper) they go off and “exchange emails individually 
with the 
organizations that run stratum 1 servers, as well as negotiate permission to 
use them.” 
to source the root time for the system. I would have thought that some sort of 
combo 
of on site and off site sources would be at the “top of the tree”.

Bob

> On Jun 21, 2019, at 2:20 PM, Marco Davids via time-nuts 
>  wrote:
> 
> Opinions, anyone?
> 
> https://blog.cloudflare.com/secure-time/amp/
> 
> ("Introducing time.cloudflare.com")
> 
> --
> Marco
> 
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Re: [time-nuts] Cloudflare

[David C. Partridge]

As an erstwhile "white-hat" hacker/penetration tester I can say with some 
confidence that the threat is real, and that NTP (as with other core services 
on the net) really does *need* to be secured.

This isn't just scare-mongering.

David

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Marco 
Davids via time-nuts
Sent: 21 June 2019 19:21
To: time-nuts@lists.febo.com
Cc: Marco Davids
Subject: [time-nuts] Cloudflare

Opinions, anyone?

https://blog.cloudflare.com/secure-time/amp/

("Introducing time.cloudflare.com")

--
Marco



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Re: [time-nuts] Cloudflare

[Loron, Peter]

I don't know anything beyond what Is in the press release, but Cloudflare 
generally does good stuff. Their work on the secure protocol is great. Looking 
forward to having it supported broadly.

I wouldn't expect the quality of the time from their NTP system to be notably 
different from any other stratum 1 provider.

-Pete

On 6/21/19, 1:03 PM, "time-nuts on behalf of Marco Davids via time-nuts" 
 wrote:

Opinions, anyone?

https://blog.cloudflare.com/secure-time/amp/

("Introducing time.cloudflare.com")

--
Marco

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Re: [time-nuts] GPSDO 10MHZ Splitter

[Paul Bicknell]

Hi you can always use a resistive splitter 

So if you have an output impedance of 50 ohm 

You use 2 off  50 resistors  to feed 2 off 50 ohm loads  / signals to other
equipment with a 50 ohm input

So we have  a load comprising of 2 off 100 ohm loads in parallel = 50 ohm 

This method is often used to supply several devices and 4 way splitters are 
Often used in the RF industry remembering the voltage / power reduction for
each splitter 

I personally will be using a 4 way splitter on my LEO Bodnar for the 
10 mhz reference noting that the LEO Bodnar has a selectable current for its
output 

Coax T connectors should be avoided when using square wave signals
Regards P




-Original Message-
From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Don
Meadows
Sent: 21 June 2019 15:28
To: time-nuts@lists.febo.com
Subject: [time-nuts] GPSDO 10MHZ Splitter

Is there an easy, and cheap way to add a splitter the 10Mhz signal 
from GPSDO, without going to a distribution amplifier to
feed two different devices?

I really don't want to build a complicated project, or 
spend $200.00 dollars for an 8 output distribution amp
off the net.  One output would be dedicated for my
 counter time base, and the other would be an 'extra' 
10MHZ source for another counter, or just to display on the scope.

I don't have a GPSDO yet, I just can't decide on one.
I am leaning to the Trimble, but it's still undecided.

Could anyone comment on buying a "Refurbished by Seller"
GPSDO on E-bay. They are a few dollars cheaper, but I really
want one I can have trust and confidence in.

Sorry for the long post.
Thanks, Don



Sent from Mail for Windows 10

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-
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Internal Virus Database is out of date.


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Re: [time-nuts] GPSDO 10MHZ Splitter

[Dave ZL3FJ]

As regards the GPSDO, check this out-
http://www.leobodnar.com/shop/index.php?main_page=product_info&cPath=107&products_id=301
I think there's also a US distributor somewhere..
DaveB, NZ

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Don 
Meadows
Sent: Saturday, June 22, 2019 02:28
To: time-nuts@lists.febo.com
Subject: [time-nuts] GPSDO 10MHZ Splitter

Is there an easy, and cheap way to add a splitter the 10Mhz signal from GPSDO, 
without going to a distribution amplifier to feed two different devices?

I really don’t want to build a complicated project, or spend $200.00 dollars 
for an 8 output distribution amp off the net.  One output would be dedicated 
for my  counter time base, and the other would be an ‘extra’ 
10MHZ source for another counter, or just to display on the scope.

I don’t have a GPSDO yet, I just can’t decide on one.
I am leaning to the Trimble, but it’s still undecided.

Could anyone comment on buying a “Refurbished by Seller”
GPSDO on E-bay. They are a few dollars cheaper, but I really want one I can 
have trust and confidence in.

Sorry for the long post.
Thanks, Don



Sent from Mail for Windows 10

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Re: [time-nuts] Cloudflare

[Hal Murray]

> Would love to have the feedback :)

Looks good.  Thanks.

You should probably setup another web page with just the technical details.

What are you going to do about leap seconds?  Smear or not?

DNS for time.cloudflare.com gives 2 IPv4 addresses and 2 IPv6 addresses.  Are 
they all equivalent in terms of routing?  Or would I maybe get (slightly) 
better time if I picked the right one?


-- 
These are my opinions.  I hate spam.




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Re: [time-nuts] GPSDO 10MHZ Splitter

[Dana Whitlow]

One can reduce the gulp factor mentioned by Scott quite a bit by buying
one of the non-connectorized versions from Mini-Circuits and wiring up
one's own BNC connectors.

One thing to keep in mind with these isolating splitters is that the
isolation
between outputs is good only if the impedance of the driving source is
pretty
accurately 50 ohms resistive.  This will not generally be true if the
source is
logic gate of some kind, although a parallel combination of several HCMOS
or ACMOS inverters combined with a series output resistor to bring the
output impedance up to 50 ohms will probably work well.

Dana   (K8YUM)

On Fri, Jun 21, 2019 at 12:18 PM W7SLS  wrote:

> A couple of ideas:
>
> Make one:
>
> Several hours and a few $  (cheap if you value your time as free)
> agree, not a lot of isolation between the outputs
> Case, connector, and three 16.67 ohm resistors
> in —> 16.67 ohms —> 16.67 ohms to output 1
>—> 16.67 ohms to output 2
>
> Ref:
> https://www.markimicrowave.com/blog/how-to-make-an-n-way-power-splitter/
>
> Perhaps free (may or may not work):
>
> Television 75 ohm splitter
> agree, mismatch between 75 ohms and 50 ohms
> agree, ugh to F connectors
>
> Ref: I don’t know if this just occurred to me, or if I read it
> (e.g., on this group)
>
> Buy one:
>
> Example: Mini-Circuits ZSC-2-1+, about $50 new
>
> https://www.minicircuits.com/WebStore/dashboard.html?model=ZSC-2-1%2B <
> https://www.minicircuits.com/WebStore/dashboard.html?model=ZSC-2-1+>
>
> Gulp:
>
> Your mileage may vary
> BNC-T connector
>
> As mentioned elsewhere:
>
> Legacy RGB distribution boxes (e.g. Extron), about $40 on auction
> sites
> Yes, they are 75 ohms, but may be fine, or you can change the
> internal resistors to move to 50 ohms.
>
> And of course there are other ($$$) solutions.
>
> (Obviously) I defer to the wisdom of the group (and perhaps groans and eye
> rolls).
>
> Best of luck, whatever you choose.
>
> Scott
> W7SLS
>
>
>
>
> > On Jun 21, 2019, at 7:27 AM, Don Meadows  wrote:
> >
> > Is there an easy, and cheap way to add a splitter the 10Mhz signal
> > from GPSDO, without going to a distribution amplifier to
> > feed two different devices?
> >
> > I really don’t want to build a complicated project, or
> > spend $200.00 dollars for an 8 output distribution amp
> > off the net.  One output would be dedicated for my
> > counter time base, and the other would be an ‘extra’
> > 10MHZ source for another counter, or just to display on the scope.
> >
> > I don’t have a GPSDO yet, I just can’t decide on one.
> > I am leaning to the Trimble, but it’s still undecided.
> >
> > Could anyone comment on buying a “Refurbished by Seller”
> > GPSDO on E-bay. They are a few dollars cheaper, but I really
> > want one I can have trust and confidence in.
> >
> > Sorry for the long post.
> > Thanks, Don
> >
> >
> >
> > Sent from Mail for Windows 10
> >
> > ___
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Re: [time-nuts] Cloudflare

[Sanjeev Gupta]

Bob,

The hardware is cheap.  The software is free.  The skills to deploy are
widely available.  But...

A cable run from your rack in the middle of the datacenter, through to the
roof, is either impossible or thousands of dollars and weeks of planning.

Data centers can run wires within the building for exorbitant costs, asking
them to run one to the exterior is, well, impossible.

-- 
Sanjeev Gupta
+65 98551208 http://www.linkedin.com/in/ghane


On Sat, Jun 22, 2019 at 6:06 AM Bob kb8tq  wrote:

> Hi
>
> Given the relatively low cost of a GPS based “Stratum 1” NTP, it’s not
> real clear
> why (at the end of the paper) they go off and “exchange emails
> individually with the
> organizations that run stratum 1 servers, as well as negotiate permission
> to use them.”
> to source the root time for the system. I would have thought that some
> sort of combo
> of on site and off site sources would be at the “top of the tree”.
>
> Bob
>
> > On Jun 21, 2019, at 2:20 PM, Marco Davids via time-nuts <
> time-nuts@lists.febo.com> wrote:
> >
> > Opinions, anyone?
> >
> > https://blog.cloudflare.com/secure-time/amp/
> >
> > ("Introducing time.cloudflare.com")
> >
> > --
> > Marco
> >
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Re: [time-nuts] Cloudflare

[Paul]

On Fri, Jun 21, 2019 at 9:12 PM Hal Murray  wrote:
You should probably setup another web page with just the technical details.

What are you going to do about leap seconds?  Smear or not?

DNS for time.cloudflare.com gives 2 IPv4 addresses and 2 IPv6 addresses.
Are
they all equivalent in terms of routing?  Or would I maybe get (slightly)
better time if I picked the right one?

Your questions are answered in their blog post.
1) No smear.
2) Anycast.

I'm pretty sure the implication is they'll provide consistent secure time
to their coverage area not necessarily the best time.  Which see
"Roughtime".
The jitter numbers are quite good from my work to the NYC Equinix
colocation facility (13ms rtt).
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Re: [time-nuts] Cloudflare

[Bob Bownes]

Most of the good data centers I’ve used either offer a connection to a stratum 
1 server or are more than happy to put a antenna on the roof. Many offer 
microwave as a third redundant circuit path, which requires an antenna. All for 
a price, of course. 

When I worked for an ILEC, many moons ago, we had two and a half floors at 60 
Hudson St. Our stratum 1 antenna was literally glued to a window. Next to a 
10GHz dish. :)

My hotel in Toronto two weeks ago overlooked a building that was clearly 
someone’s data center, based on the 6 generators, massive AC, numerous 
microwave links, and yes, GPS bullet antennas, covering the roof. 

Bob

> On Jun 21, 2019, at 22:01, Sanjeev Gupta  wrote:
> 
> Bob,
> 
> The hardware is cheap.  The software is free.  The skills to deploy are
> widely available.  But...
> 
> A cable run from your rack in the middle of the datacenter, through to the
> roof, is either impossible or thousands of dollars and weeks of planning.
> 
> Data centers can run wires within the building for exorbitant costs, asking
> them to run one to the exterior is, well, impossible.
> 
> -- 
> Sanjeev Gupta
> +65 98551208 http://www.linkedin.com/in/ghane
> 
> 
>> On Sat, Jun 22, 2019 at 6:06 AM Bob kb8tq  wrote:
>> 
>> Hi
>> 
>> Given the relatively low cost of a GPS based “Stratum 1” NTP, it’s not
>> real clear
>> why (at the end of the paper) they go off and “exchange emails
>> individually with the
>> organizations that run stratum 1 servers, as well as negotiate permission
>> to use them.”
>> to source the root time for the system. I would have thought that some
>> sort of combo
>> of on site and off site sources would be at the “top of the tree”.
>> 
>> Bob
>> 
>>> On Jun 21, 2019, at 2:20 PM, Marco Davids via time-nuts <
>> time-nuts@lists.febo.com> wrote:
>>> 
>>> Opinions, anyone?
>>> 
>>> https://blog.cloudflare.com/secure-time/amp/
>>> 
>>> ("Introducing time.cloudflare.com")
>>> 
>>> --
>>> Marco
>>> 
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