Monitoring WWVB 

I had a thought about monitoring WWVB on 60KHz the other day. Since I have a really stable source of time (GPS disciplined Rubidium Oscillator) why not log the phase of WWVB relative to the GPS time instead of monitoring the amplitude of the signal?

I can think of a few ways to do this that would be easy to implement:

1) Pure analog setup with a ramp and a sample/hold circuit
2) Frequency counter with a & b inputs to measure the time.
3) Microprocessor to measure the time difference.

Since I have a suitable counter, maybe I'll set up to watch the time difference over a few days to see how it looks before deciding on a final approach.

Thoughts anyone?

Cheers,

Keith
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Maker Faire 

I had a really nerdy weekend! I spent Saturday at the Maker Faire in San Mateo. I've been a big fan of Make magazine since it debuted, and I have been to all of the Bay Area Maker Faires. This year was really great. A mind-bending experience as always. Plenty of Steampunk, model rockets, trebuchets, mad science, tesla coils, robots, you name it. I highly recommend attending.

The other nerdy thing I did was to go to Sturgeon's mill, which is a steam powered saw mill in western Sonoma County. The mill has been on this spot since the 1920s. When it was shut down in about 1963, Wade Sturgeon, one of the original partners, continued living on the site. He had the foresight to keep the rain off the old mill, and to go out once a week with his oil can to keep everything lubed and moving. I wish more people could think ahead that way. Recently a group including Wade's family got together and brought it all back to life. When you stand on the deck as they saw logs, you can feel the pulse of the steam engine and hear the exhaust note change as the saw blade bites into the log. IT'S ALIVE!!!

Cheers,

Keith
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Decametric Receiver Mods 

I've been playing with the TenTec 1056 receiver to optimize its performance measuring solar noise. One of its features as a communications receiver is the fairly narrow and adjustable bandpass filter. The manual doesn't say, but it appears to have about a 1KHz bandwidth. This is really too tight for picking up broadband noise from the sun.

The guys at Fringe Dwellers recommend adding a switch to allow you to bypass the bandpass filter stage altogether. This goes a little too far the other way for my suburban location. The Radio Jove receiver has a multi-pole filter with a 3.5 KHz bandwidth. I decided to follow their lead. I put a simple RC filter in place and so far it seems to be working well.

Here's how it is hooked up. Remove the "Mute" jumper and put an SPDT switch across it with the common to the right end. Across R12 (3.3K), put a series combination of a 1K resistor with a 0.047uF cap. The resistor goes to the right, the other end of R12 is ground. The node where the resistor joins the cap connects to the other end of the bypass switch. Voila, a simple RC filter.

Now to record data for a couple of days and see how my results compare to others.

Cheers,

Keith
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Astronomy Day 2010 at the RFO 

We are all set up for Astronomy day here at the Robert Ferguson Observatory. We are getting a good crowd for Solar observing which will last until 4:00 PM. Then after a break for a meeting and dinner, we'll be back to show the night sky. I brought my Orion 8" dob, several others will be here with small scopes, and all of the large scopes in the observatory will be operating. We also have not 1, but 4 lecturers who will be giving a variety of talks starting at 8:00 PM.

Although there are no sunspots today, the sun appears to be active in the decametric radio spectrum. Dean has picked up several noise bursts on the Radio Jove receiver.

Wherever you are, there should be some club doing public astronomy today. If not, at least go out and look at the moon and Venus tonight just after sunset.

Dark Skies!

Keith
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Radio-SkyPipe Data on-line 

I have some rudimentary plots available from Radio-SkyPipe on-line now. You can see the data here. The prominent red track is from the 24.8KHz Gyrator II receiver monitoring NLK at Jim Creek, Wa. The flat orange track near the bottom is from the 20.1MHz receiver. I'm still working on that one. I hope to have something on the other channel soon too.

I've also taken info from some of my posts here and started to create some "permanent" pages on my solar monitor project. This Linkwill take you there. So far, it just covers the system mainframe and bar graph modules. Over the next few weeks I'll add pages for each receiver/sensor too.

Cheers,

Keith
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