organlists@pacbell.net said:

There are many many the low cost units and only a few of the expensive ones.

It would be interesting to see how many of the expensive WWVB boxes were
still running when they made the switch in transmission format.  I expect
most of the places that needed good time had already switched to GPS.

--
These are my opinions.  I hate spam.

I'll add to the comments the spectracoms are phase tracking receivers and
do not work on the new BPSK  signal.
As mentioned over the years I and others have offered approaches to
correcting the carrier. My last approach that worked very well over great
distances was the cheatin d-psk-er. Works what can I say. But it was never
kit-ed or anything, nor did I want to get into that business. My hats off
to those who make that effort. But I released everything on time-nuts and
to other people who wanted to post it.
Essentially an arduino driven by gps for time and the tick that new how to
create the actual BPSK data stream and to undo what NIST did. It flipped it
back at the same time. The cheatin part was using GPS as the time source.
It also required a soldering iron...
Simple, dump, stupid. The best approach.

As others say the spectracoms certainly have a nice display but the new
WWVB clocks are pretty darn nice for $50-70 as I recall.

Regards
Paul
WB8TSL

On Thu, Mar 22, 2018 at 3:47 PM, Hal Murray hmurray@megapathdsl.net wrote:

paul swed write:

When the German PTB made effort to increase the accuracy and reliability
of the DCF77 long wave receiver in the 1980s, they implemented thus in a
way that old receivers of the original AM modulation would not be affected:
https://www.ptb.de/cms/en/ptb/fachabteilungen/abt4/fb-44/ag-442/dissemination-of-legal-time/dcf77/dcf77-phase-modulation.html

If I remember correctly then there were some discussions with folks a
NIST when they were going to introduce their new modulation scheme, but
even though the guys at NIST knew that their approach would break
existing receivers, they implemented it anyway that way, even though
other (compatible) ways would have been available. :-(

Martin

The AM modulation stuff is not affected also by the new WWVB signal.
The WWVB problem affecting timing and frequency receivers is the
180deg phase modulation where the DFC77 is only 13deg and is
randomized so that the mean phase is zero.

On Fri, Mar 23, 2018 at 10:35 AM, Martin Burnicki
martin.burnicki@burnicki.net wrote:

Hi

There is a lot of analysis on the WWVB change in the archives. The bottom line
seems to be that the change did not impact wall clocks and watches. The number
of companies running WWVB phase synchronous gear appears to have been
near zero at the time of the change. There certainly was no giant flood of gear
onto eBay. There also does not seem to have been an uproar in the commercial
sector.

Bob

Martin
NIST did preserve the AM data so that the cheapy clocks typically worked.
But phase tracking receivers don't.
Regards
Paul
WB8TSL

On Fri, Mar 23, 2018 at 5:35 AM, Martin Burnicki <
martin.burnicki@burnicki.net> wrote: