Very good article on the new Facebook Data Center in Prineville, Oregon via Wired.com. One of the interesting aspects of the data center design is the energy efficiency aspect. In a data center that services 800 million users, shaving a few percentage points off of the energy bill represents huge savings.
According to the article, the location was chosen for its climate. The area has low humidity, thus allowing the use of evaporative cooling system verses the conventional refrigeration cycle systems most often used.
Another area is in the servers themselves. Facebook decided to design their own servers, using a stripped-down platform, larger heat sinks, slower fan speeds, etc to reduce the amount of electricity used.
All in all the article is well worth reading, as the future of broadcasting will be centered on data centers such as this one.
CHU is an HF time signal station operated by the National Research Council of Canada. It operates 24/7 and announces the hour and minute each minute of every day on frequencies 3,330, 7,850, and 14,670 KHz. This is the Canadian counterpart to WWV and WWVH. In the strictest sense of the term, it is a broadcasting station, although many would also classify it as an HF utility station as well. Many countries had HF time signal radio stations at one time, but there are fewer now. Back in the day before GPS, these time signals were critically important to anyone needing coordinated event timing. We used the carrier frequency from WWVH as our frequency standard for test equipment. WWV and WWVH also transmitted a very accurate 1 kHz tone for the same purpose. According to the CHU website:
Normally CHU’s emission times are accurate to 10-4 s, with carrier frequency accuracy of 5×10-12, compared to NRC’s primary clocks, which are usually within 10 microseconds and 1×10-13 compared to UTC.
Additionally, every minute between 31 and 39 seconds, CHU broadcasts FSK time code with a Bell 103 standard (2225 Hz mark, 2025 Hz space) at 300 bits/second (IRIG time code). This could be used as a backup for GPS time clocks on automation systems if GPS were to fail for some reason. One would have to write a little software program to decode the hex output and reset the computer clock once per minute accordingly. That should not be too hard. LINUX information and software can be found here. More on CHU time code here.
CHU Ottawa, Ontario, Canada
In my location 3,330 KHz is audible 24/7. That signal is transmitted with a carrier power of 3 KW into a non-directional vertical dipole antenna as is 14,670 KHz. The 7,850 KHz signal is transmitted with a carrier power of 10 KW into the same type of antenna.
Canadian Time Signal station CHU, aerial view
There is some discussion of adding an additional time station transmitter in western Canada and of changing the modulation from AM to DRM or at least adding some type of DRM service.
Just because I can, here are a few pictures of the inside of a rather expensive 80-amp DC-rated circuit breaker:
80 amp DC rated circuit breaker open
What is the difference between a DC-rated breaker and an AC-rated breaker? Good question. Because DC is, well DC, the current is continuous. Once an arc is struck, greater separation is needed between conductors to extinguish the arc. Using an AC breaker in a DC application can lead to an internal arc and fire. That would be a bad outcome.
Just how did the insides get exposed, one might ask? Well, there I was working on a solar installation with said breaker placed on a horizontal surface waiting for installation when somehow it was knocked to the floor, creating a large crack in the side of it. Angry I was because this thing set me back some fifty dollars.
80 amp DC rated circuit breaker closed
This picture shows the breaker closed, the contacts are still undercover to the left of the exposed parts. What is cool is one can get a good idea of how a circuit breaker works. As the current flow increases, the magnetic field around the coil increases. When it reaches the trip point the small steel piece is pulled down, causing the mechanical assembly to unlock and open the contacts.
Old tech stuff that is taken for granted probably has saved millions of lives since electrical use became widespread.
Still in use as the main transmitter after 42 years at WCKL 560 KHz, Catskill, NY.
CCA AM1000D transmitter, WCKL Catskill, NY
The last seven years or so, it has not had much use, the station being caught in some strange LMA with Clear Channel, then sold to the Black United Fund of NY something or another. They basically had it dark, turning it on for a few days each year to as not to lose their license. Finally, they LMA’d it to Family Broadcasting (not to be confused with Family Radio). There are rumors of a sale, but it remains to be seen.
They have been broadcasting an eclectic, free-form programming style which appears to be the work of mostly volunteers.
The station was first licensed in 1970, thus this is the original transmitter:
CCA AM 1000D nameplate, WCKL Catskill, NY
Towers are 446 feet tall, which works out to 90 degrees at 560 KHz.
WCKL 560 KHz antenna array
The station is licensed to Catskill, but the transmitter site is located in Hudson, across the river. With the current ownership situation in flux, I would characterize the operation as “tenuous.”
The transmitter itself is a pretty simple high level modulation tube type transmitter. It uses 4-400 tubes, like the RCA-BT1AR transmitters, and is built around a similar design, which makes sense as they were designed and built by former RCA engineers. One of the CCA principles, Bernie Wise, still makes Energy Onix transmitters about 10 miles away in Valatie, NY.
Parts are fairly generic and still available. Things like the modulation transformer may be harder to come by, however, Goodrich Electronics, Harbach Electronics, Energy Onix and others will be able to steer one in the right direction. I’d put up a schematic if I could find one.
I find these older tube-type transmitters often sing with modulation, especially the higher frequencies. That sound and the soft sound of the blower moving air is the sound of radio, at least to me.
