KB6NU's Ham Radio Blog

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Building a WWVB receiver, episode 2

Posted: 27 Dec 2015 11:09 AM PST
http://feedproxy.google.com/~r/kb6nu...m_medium=email

The antennas for WWVB, the NIST time-signal radio station near Fort
Collins, Colorado.

A couple of years ago, WWVB, the National Institute of Standards and
Technology radio station that sends out time signals 24 hours a day, seven
days a week on 60 kHz, celebrated its 50th anniversary. At the time, I
wasÂ*interested in building a WWVB receiver, but when IÂ*found out that it
wasnt easy to do, my enthusiasm waned.

Well, a couple of days ago, a reader e-mailed me. He asked, Have you seen
this Everset Technologies Users Guide ? and attached a PDF of the ES100
Application Development Kit. According to the document, the Â*ES100
Application Development Kit (ADK) is a dual-antenna receiver module for the
phase-modulated time-code signal that is broadcast from the WWVB radio
station.

I replied that no,Â*I hadnt seen that, but whileÂ*it does really look
interesting, it looks likeÂ*its vaporware. The URL given in the users guide,
eversetclocks.com, doesnt seem to be working. Googling Everset
ES100Â*returns links to a couple of posts on the time-nuts mailing list, a
press release announcing the first shipment of ES100 ICs, and even a
LinkedIn profile for some guy that worked at Xtendwave/Everset. None of
these, however, produced any promising further information.

While researching this post,Â*I happened to come upon the website for C-Max
Time Solutions.Â*Â*I believe that this is the company that sold the CMMR
modules. It looks like theyre still selling WWVB receiver chips. They have
two different ones, the CME6005 sells for $3, and the CME8000 sells for
$3.75. They also sell antennas and other related stuff.

AnotherÂ*approach would beÂ*to hack an existing WWVB clock. I describe a
couple of approaches in my original post. The most promising seems to
beÂ*the time-nutsÂ*post that describes how to hack a Sony Dream Machine AM/FM
radioÂ*and liberate the WWVB receiver module. This module uses the
Temic Â*U4226B Time Code Receiver IC. Unfortunately, this IC seems to also
be no longer available.

I was thinking about hacking the Radio Shack WWVB clock that I have, but it
didnt look like Id be able to pry the case open without destroying it, and
I dont really want to destroy it at this point. Another source might be
thrift shops. Here in Ann Arbor, the Kiwanis Club operates a weekly rummage
sale,Â*and there are several other thrift shops in the area. I plan on doing
a little thrift store shopping soon to see if I can find a used
WWVBÂ*clock.Â*If any of you happen to have one of these WWVB clocks or WWVB
receiver chips that you no longer want, Id be happy to make you an offer
forÂ*them.
More VLF fun

Yesterday, while on my Saturday morning walk, I had my HT and was talking
to Ed, KD8OQG, and Thom, W8TAM, about this e-mail exchange. Ed and Tom are
both SDR enthusiasts, and at one time, Ed and I were talking about building
a Blitzortung lightning detector, which detects VLF emissions of lightning
strikes.

We got to thinking that this might be possible with some kind of SDR
receiver and an appropriate converter. Thom is going to look into this.

And, talking about lightning detection, we got to thinking that we might be
able to include lightning detection in this project as well. According to
the National Lightning Safety Institute, Various detector detection
receiver algorithms operate at different frequencies and wavelengths:
Boltek Stormtracker in the Low Frequency range 100-700 kHz; Vaisala GAI
NLDNÂ*at 100-400 kHz; NMT Lightning Array at VHF 60-78 MHz; LIS and OTD
optical at 777.4 m; Vaisala SAFIR VHF 109-119 MHz; Vaisala GAI LDAR II at
50-120 MHz; GAI VLF at 20-50 KHz; the UK Meteorological Office RDI at 9.8
KHZ; etc. NASA has published an excellent summary of families of lightning
detectors.

Thats where we are right now. More to come, I hope.

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