Hey: Don't forget that the cable itself is noisy when moved. Especially
Teflon insulation.
Don
On 2021-08-30 06:51, Bob kb8tq wrote:
Hi
This sort of trouble with BNC’s has been going on a lot longer
than they have been coming in from China. A lot of folks use
them *way* past the point they
On 8/29/21 11:07 PM, Anders Wallin wrote:
FWIW we've played with various SMA-to-SFP converter boards in the lab for
10MHz or 100MHz distribution.
A bare-bones SFP board is e.g.
https://github.com/aewallin/SFP-Breakout-Board
That interfaces directly to the differential AC-coupled TX and RX pins
Hi
This sort of trouble with BNC’s has been going on a lot longer
than they have been coming in from China. A lot of folks use
them *way* past the point they should. They do indeed wear
out. They also come loose on the cable.
We went a bit nuts “killing off” all the BNC cables in the area
back
On Sun, 2021-08-29 at 09:21 -0500, Dana Whitlow wrote:
> I believe that a significant problem in my case was not leakage
> through the
> shield, but
> rather common-mode currents on the cable. My experiences were with
> RG-6
> style cable,
Chiming in with a maybe tangential issue.
I had some
FWIW we've played with various SMA-to-SFP converter boards in the lab for
10MHz or 100MHz distribution.
A bare-bones SFP board is e.g.
https://github.com/aewallin/SFP-Breakout-Board
That interfaces directly to the differential AC-coupled TX and RX pins of
an SFP.
If you want some buffering (and
David I. Emery writes:
> On Sun, Aug 29, 2021 at 10:43:51AM -0400, paul swed wrote:
> Not completely clear what the common
> mode Z of the things is at 10 MHz...
Twisted pair is 135 Ohm.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since
On Sun, Aug 29, 2021 at 10:43:51AM -0400, paul swed wrote:
> We my only issue is every time we had a lightning storm it seemed to
> fry the ICs.
While they may not have ideal behavior with temperature (and
related phase/group delay changes) the old antique 10Mbs era balanced
twisted
ethernet cable?
Most Thinnet has both a braided shield and a foil wrap.
Robert
> --3
Date: Sun, 29 Aug 2021 09:21:32 -0500
From: Dana Whitlow
Subject: [time-nuts] Re: Query about List and about 10 MHz Distro
To: Discussion of precise time and frequency measurement
On 8/29/21 10:29 AM, Robert DiRosario wrote:
Andrew Sureflex (FSJ) is a lot more flexible then the LDF4 Healix,
which is what you find a
lot of on ebay and at hamfests.
Here is some 1/4" Sureflex, new:
Andrew Type N Male to Type N Male Sureflex Cable 30 feet
F1RNA-PNMNM-30-L1 NEW!
This has been an interesting thread.
I purchased some 1/4" FSJ with BNC connectors from the usual auction site years
ago for time nuts use but never installed it. It does seem to be a bit of a
hassle to use in my time lab (I do use some FSJ with N connectors in parts of
my home amateur radio
Hi
With *any* cable setup, proper termination is vital. An improperly terminated
balanced line can be just as bad as a poorly terminated coax. Things like
common mode chokes are part of a *lot* of setups.
What gets messy is that a lot of gear does not properly terminate the cable.
It’s high-z
Andrew Sureflex (FSJ) is a lot more flexible then the LDF4 Healix, which
is what you find a
lot of on ebay and at hamfests.
Here is some 1/4" Sureflex, new:
Andrew Type N Male to Type N Male Sureflex Cable 30 feet
F1RNA-PNMNM-30-L1 NEW!
https://www.ebay.com/itm/173863049072
US $30.00 +
On Sun, 29 Aug 2021 03:30:23 -0400, time-nuts-requ...@lists.febo.com
wrote:
Re: time-nuts Digest, Vol 208, Issue 23 (message 3)
> Date: Sat, 28 Aug 2021 18:57:08 -0500
> From: Dana Whitlow
> Subject: [time-nuts] Re: Query about List and about 10 MHz Distro
> To: Discussion of
Robert wrote:
What about double shielded RG-223, or Thinnet ethernet cable?
Most Thinnet has both a braided shield and a foil wrap.
IME, thinnet cable is notoriously leaky. I have also not had success
with double-shielded cables such as RG-223.
Unless you go all the way to hardline (some
exactly
On Sun, Aug 29, 2021 at 10:45 AM Dana Whitlow wrote:
> Andy,
>
> Balanced twisted pair may be helpful, but only if adequate precautions are
> taken to
> avoid creation of common mode *currents *on the line*.*
>
> Dana
>
>
> On Sun, Aug 29, 2021 at 9:34 AM Andy Talbot wrote:
>
> > Hence
Andy,
Balanced twisted pair may be helpful, but only if adequate precautions are
taken to
avoid creation of common mode *currents *on the line*.*
Dana
On Sun, Aug 29, 2021 at 9:34 AM Andy Talbot wrote:
> Hence my observation that balanced twisted pair might be a better solution
> than coax
Andy
The balanced line does work and does reduce the emissions on a 160 ft run.
Used it for 1, 5, 10 MHz.
We my only issue is every time we had a lightning storm it seemed to
fry the ICs.
The line drivers and receivers were analog devices ADSL type technology.
Was a bit of a pain to deal with
Hence my observation that balanced twisted pair might be a better solution
than coax for 10MHz distribution
Removes all possibility of ground loops
Andy
www.g4jnt.com
On Sun, 29 Aug 2021 at 15:22, Dana Whitlow wrote:
> I believe that a significant problem in my case was not leakage through
I believe that a significant problem in my case was not leakage through the
shield, but
rather common-mode currents on the cable. My experiences were with RG-6
style cable,
namely a cable that mostly went around the outside of the house for TV
distribution.
I get all the TV I want with an indoor
Hi
Skin depth is what gets you with most coax at 10 MHz, even with the “double
shield” stuff. Hardline with a nice heavy outer would do better. It’s not
terribly
practical around the typical lab. Might not be a bad choice for a “burry in the
yard”
setup though. With normal cable, the losses
What about double shielded RG-223, or Thinnet ethernet cable?
Most Thinnet has both a braided shield and a foil wrap.
Robert
On 08/28/2021 08:26 PM, Bob kb8tq wrote:
Hi
Anything you do that has a bunch of 10 MHz cables running out from here or there
will impact your ability to listen to WWV
Bob,
In my case simply disconnecting the long interconnecting cables at both
ends almost
completely eliminated the problem. Hence my expectation that use of fiber
optics
would be effective.
Dana
On Sat, Aug 28, 2021 at 7:27 PM Bob kb8tq wrote:
> Hi
>
> Anything you do that has a bunch of 10
On 8/28/21 4:57 PM, Dana Whitlow wrote:
Bob, my own motivation for going to fiber was entirely different. I
simply wanted to
run 10 MHz all over the place from reference sources in disparate
locations in the
house, and I quickly discovered that cable leakage was embarrassingly
severe. So
I
Hi
Anything you do that has a bunch of 10 MHz cables running out from here or there
will impact your ability to listen to WWV at 10 MHz :) Other than killing all
the sources,
there is no silver bullet.
Bob
> On Aug 28, 2021, at 7:57 PM, Dana Whitlow wrote:
>
> Bob, my own motivation for
Bob, my own motivation for going to fiber was entirely different. I
simply wanted to
run 10 MHz all over the place from reference sources in disparate
locations in the
house, and I quickly discovered that cable leakage was embarrassingly
severe. So
I shut down and began contemplating a fiber
Hi
With a whole variety of pretty good OCXO’s going for cheap money
on eBay, it’s likely less expensive to do cleanup oscillators on the link
compared to going crazy with low noise optical this or that. Yes, you
will be getting something in the high 150’s for noise, but still pretty good
for $10.
White rabbit seems pretty good for time synced over fiber. PTP with
enhanced stability profile. It's a IEEE standard. It seems to work for
CERN. Lately I've been looking at Cisco devices that can support it. It
whould be nice if I could find hardware that'll support it more easily...
Maybe
I was looking for something similar about 18 months or so ago. Although I
haven't taken any
action yet, I concluded that one could do a nice job for under $200 per
segment, including the
transmitter and receiver modules and lots of connectorized multimode
fiber. What I *don't* know
is what the
Look at Synchronous Ethernet.
On Sat, 28 Aug 2021, 17:51 AC0XU (Jim), wrote:
> I am hoping that you can help me about a couple of things:
>
> 1) My time-nuts summaries sometimes appear unformatted and unreadable. All
> the text from all the postings is crammed together without spacing. How
On 8/28/21 9:56 AM, Andy Talbot wrote:
When I asked about this on another Group a while back, I was told the phase
noise made it an undesirable solution.
Although I never tried it, I would imaging balanced shielded twisted pair
would be a better way to go. Immune from ground loop problems
On 8/28/21 9:51 AM, AC0XU (Jim) wrote:
I am hoping that you can help me about a couple of things:
1) My time-nuts summaries sometimes appear unformatted and unreadable. All the
text from all the postings is crammed together without spacing. How can I fix
it?
2) I want to distribute 10 MHz
When I asked about this on another Group a while back, I was told the phase
noise made it an undesirable solution.
Although I never tried it, I would imaging balanced shielded twisted pair
would be a better way to go. Immune from ground loop problems than can
beset coax distribution and a whole
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