Receiver compatibility with modern WWVB

[tkamiya]

I was looking into WWVB receivers, in particular, spectracom 8164.  Then I ran into another article that said in 2012, phase modulation was added/replaced the signal format, so that many receivers became instantly obsolete.

Are there any list or detailed discussion of which models still work today?  (2019)

I'm now in sort of a quest to acquire as many types of time/frequency receivers and systems as I can.  So I really don't care if these are less accurate/precise than whatever else.  So please don't factor that into this discussion.  (and NO, I am not going to buy Hydrogen Maser and be done with it) 

Thanks as always. 

[David Hess]

The time-nuts@lists.febo.com email list discussed the change in modulation and its effect.  That is where I would start.

[tkamiya]

Someone else has told me to go to time-nuts on something else I asked.

Is this type of question not appropriate for eevblog?  I'm also a member of time-nuts but I'm not too familiar with their discussion format.  So I thought I'd start here.

[David Hess]

Someone else has told me to go to time-nuts on something else I asked.

Is this type of question not appropriate for eevblog?

No, not at all.  Your question is fine for the forum here.

I'm also a member of time-nuts but I'm not too familiar with their discussion format.  So I thought I'd start here.

The time-nuts@lists.febo.com email list just has many experts on this subject so your question is better answered there.  I think past posts are available on a web accessible archive.

[ZigmundRat]

There’s lots of discussion in the time-nuts archives. But long story short, phase tracking or synchronous receivers like the 8164 no longer work. They can be made to work with some modification though. But the only receivers that work with the new format are in new versions of ‘atomic’ wall clocks. If you want to play, there are now modules you can buy but they are only useful for telling time - not for disciplining.

There is an article in QST: ’A Frequency Standard for Today’s WWVB’ which describes a project that handles the new format.

Certainly you can get more accuracy with a GPSDO but it’s fun keeping the old stuff running too 

[tkamiya]

This kind of thing reminds me of my earlier days I was into ham radio.  I was in Japan, so I'd calibrate TS520 with JJY signal.  For more than 10 watts, law required "precise frequency measurement equipment", which meant 100KHz Crystal Oscillator.  Not temp compensated or oven'd.  Just a naked 100KHz AT cut (I think) generator.

If I could, I would do Loran, too but there's no one left transmitting.  It's just that over-the-air transmission has nostalgia built in for me.

Thank you for the QST article.  That certainly is an impressive piece and fine piece of engineering.  I'll have to read them few times over and come up with something similar in function.  Since frequency of concern is so low, I'm thinking there could be some software assistance to simplify the hardware quite a bit.  Or, I could extract just the PPS and drive something else.  I tend to feature creep quite a bit, so I will have to be careful.

In time of internet though, I'm really not sure if WWVB has too much future in it.  I heard there could be an issue with running the station due to congressional budget?  Times sure have changed!  I'm much older and parts are much smaller, too. 

[Conrad Hoffman]

I haven't actually installed this, but it should probably work. Make a frequency doubler with a toroid and put that on the front end. In the logic chain, bypass one X2 chip. AFAIK, pretty much all of the older time receivers no longer work because of the phase shift. They also drop the amplitude more, so even the TRF receiver I built no longer works. I need to add a track and hold chip to the locked oscillator so when the signal drops out, the thing doesn't drift. Spectracom is here in Rochester and I think everything they do now is GPS based.

[tkamiya]

I really think depending on just one technology isn't the smartest thing to do.  Loran is gone altogether, WWVB is out from commercial market, so GPS is it for both navigation and precision timing.  If it goes down, we'll have a heck of massive confusion.

[tkamiya]

I guess eBay listing of WWVB that says "Came from working environment" isn't exactly telling the truth, unless the original owner timed its shutoff exactly before the phase mod came on.

[5065AGuru]

Hi,

Here is a link to a "Dephaser" for WWVB use.

http://www.californiahistoricalradio.com/wp-content/uploads//2017/02/CHRS-Construction-BPSK-Dephaser-John-Staples.pdf

I know I have seen a similar "de-BPSKer" on Timenuts but can't find it right now.

It allowed vintage receivers to be used again as its output was at 60Khz!

Cheers,

Corby