[time-nuts] Re: NTP servers

[Gregory Beat]

A couple of years ago, I acquired a related “time-nuts” NTP appliance.  As usual, it was not working properly and waited for service time on my electronics workbench.

The ESE ES-188 is an NTP referenced Master Clock and Time Code Generator (circa 2007).
It displays nine digits (Day of Year, Hour, Minute & Second) of time, as received via a user selected NTP server.  It has option to be an NTP Server.  The newer ES-188E Master Clock is the current ESE production model.
https://www.ese-web.com/188e.htm

ES-188 Master Clocks are often found used (>10 years old) for $1,000 to $1,500 by a handful of Florida based eBay resellers.  I purchased mine for 10% of asking prices, from an eBay reseller in Oklahoma, who had no idea how it worked (“but the lights come on”).  Closer inspection demonstrated that it was not working properly, and likely why it was discarded by original owner.

Visiting the Electronics workbench, the two backup batteries (Coin Cell for backing up the User settings, and a SLA/Gel-Cell for a 4-hour operational backup) were DEAD.
In addition, a majority of the electrolytic capacitors in the DC voltage section were faulty (bulging or beginning to leak).
Two integrated circuits (7400 series) near data I/O ports were damaged (likely due to DC voltage issue, or an external induced surge event), but thankfully the CPU and Ethernet module were functional. 
Replacement parts were acquired from Digi-Key.  I used high quality Panasonic electrolytic capacitors for the DC power section.  The failed (bulging) capacitors were from a southern California “shell company” for a Chinese mfg. (telltale green capacitors, seen during earlier “Capacitor Plaque”).

The ES-188E generates several types of time code, including SMPTE LTC, ESE-TC89, ESE-TC90, ASCII (RS-232C & USB), EBU, IRIG-B and a 1PPS signal. These outputs allow the ES-188E to drive external clock displays as well as interface with computers, automation and clock systems.

The Ethernet port (RJ-45) serves a dual purpose (client/server), when the Optional NTP Server is installed or configured.
 
The ES-188E became popular for users in urban areas.
1.) Trouble getting a reliable GPS Signal into a facility, such as a basement or a building with metallic coating on the windows.
2.) Trouble getting an antenna to the outside of a facility, because the cable run will be too expensive or the facility cannot be modified, which is the case with many historical buildings.
3.) The specific facility needs to be time synchronized to a remote location through NTP, for example, universities with multiple campuses or NPR affiliate broadcast stations. ESE has a specific option for NPR broadcast station usage.

Powering up the ES-188, I configured the Master Clock settings.  
One step is selecting the primary and secondary NTP reference servers, as well as delay / latency factors.  I selected my ISP’s NTP servers (Xfinity/Comcast), instead of Google, NIST, or other known NTP references (higher latency potential).
This ESE Master Clock drives (IRIG-B) an old Masterclock TCD-26 series I (2-1/4” high digits) in the workshop (cannot internally DST adjust - since 2007).

The differences between my GPSDO references and the ES-188 are very small, 
BUT a hard-core “time-nut” would likely need restraints after a year. :-)

greg
==
Date: Sun, 21 Nov 2021 21:29:52 -0500
From: McFail Troll <time.isanapp at gmail.com>
Subject: [time-nuts] NTP servers
To: time-nuts at lists.febo.com

Hi all, I am new to the mailing list, and pretty new to timing stuff in general. I wanted to ask if any of you folks who have a more advanced set-up (synchronization via gps/radio, or just a well working rubidium clock or something) maintain a solid stratum 1 NTP server. Of course, I am aware that there are plenty of good stratum 1 NTP servers open to the public (e.g. NIST's servers), but I am curious to see if I could sync up
with some of you guys who seem to have some pretty cool set-ups.

Btw, sorry if this has been asked before on this list. 
Thanks.