An excerpt from page NIST-25 of the proposed budget linked above:<\/p>\n
NIST will discontinue the dissemination of the U.S. time and frequency via the NIST radio stations in Hawaii and Ft. Collins, CO. \u00a0These radio stations transmit signals that are used to synchronize consumer electronic products like wall clocks, clock radios, and wristwatches, and may be used in other applications like appliances, cameras, and irrigation controllers.<\/em><\/p>\n The shortwave stations WWV and WWVH are probably most familiar to radio enthusiasts, because their shortwave signals are easily audible as tones in a radio’s speaker. \u00a0But there’s a low frequency station, WWVB, at 60kHz, which sends digital time signals out across the US. \u00a0Its signals are commonly received by radio controlled “atomic clocks” and wristwatches, making it possible to have inexpensive self-setting clocks that maintain accurate time with no human intervention, using very little battery power. \u00a0They even self-adjust for daylight saving time.<\/p>\n It’s true that many of the old time and frequency uses of WWV are now handled pretty well, and often much better, by the GPS system. \u00a0GPS offers much more accurate time and frequency standards over a much broader area than the old shortwave and LF stations. \u00a0But WWV and WWVB still perform some useful functions that GPS doesn’t handle. \u00a0Those self-setting clocks aren’t really laboratory grade time references, but they are very popular in many homes, because they offer inexpensive access to time which is accurate enough for household purposes. \u00a0 Their self-setting function will stop working without WWVB. \u00a0GPS cannot be received with such low power battery operated receivers, particularly not if the receiver is in a clock that’s indoors on the first floor of a two-story house. \u00a0And there is no practical way to retrofit a GPS receiver into a consumer-priced self-setting clock, regardless.<\/p>\n If this proposal goes through, I’ll miss the tones of WWV for nostalgic reasons. \u00a0But I’ll miss the self-setting, maintenance-free clocks in my house for practical reasons.<\/p>\n The budget savings expected? \u00a0About six million dollars annually. \u00a0That’s about two cents a year per person in the US. \u00a0Or around half a percent of the GPS system’s annual taxpayer budget.<\/p>\n WWV 15 MHz Transmitter.<\/p><\/div>\n But maybe there’s hope. \u00a0The WWVB modulation scheme is simple and well-documented. \u00a0It only requires a 60 kHz oscillator with two amplitude levels, one about 17 dB lower than the other. \u00a0The signal strength is lowered at the start of each second, and restored to the higher level either 0.2s or 0.5s later, depending on whether a binary “0” or “1” is being sent. \u00a0The details of the digital protocol are documented in NIST Special Publication 432<\/a>.<\/p>\n If someone had something like a Raspberry Pi<\/a> that was synced to the proper time via NTP or GPS, it wouldn’t be that hard to write software to flip one of the Pi’s GPIO pins in the pattern corresponding to the WWVB signals as documented. \u00a0And if one used that GPIO pin to control the amplitude of a low power 60kHz oscillator, nearby radio-controlled clocks just might start working again, even if WWVB were off the air.<\/p>\n","protected":false},"excerpt":{"rendered":" Every radio enthusiast in the Western hemisphere is familiar with radio station WWV, which will have been been steadily broadcasting time signals for 100 years in October of 2019, if it makes it that long. If it makes it that long?\u00a0 Yes, the world’s oldest continuously operated radio station may cease operations, if the proposed Read More …<\/a><\/p>\n","protected":false},"author":1,"featured_media":486,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,6,4],"tags":[],"class_list":["post-485","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-computers","category-electronics","category-ham-radio"],"_links":{"self":[{"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/posts\/485","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/comments?post=485"}],"version-history":[{"count":5,"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/posts\/485\/revisions"}],"predecessor-version":[{"id":654,"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/posts\/485\/revisions\/654"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/media\/486"}],"wp:attachment":[{"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/media?parent=485"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/categories?post=485"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ag6qr.net\/index.php\/wp-json\/wp\/v2\/tags?post=485"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"http:\/\/ag6qr.net\/wp-content\/uploads\/2018\/08\/15mhz1st-large.jpg\")