I had enough! My creaky Intel Atom-based computer had enough oomph with Ubuntu to run fldigi, but just barely. It couldn't handle a browser and logging program running alongside very well. So the D945GCLF motherboard supporting an Atom 230 processor and 1 GB of RAM is now surplus. (See right.) Note that it has on-board serial and parallel I/O ports - a rarity now! (I originally chose the Atom board as an experiment to see how small a processor was really necessary. I answered that question.)
Upgrading was straightforward. I could keep the power supply, case, DVD drive, etc. The board is an MSI B75MA-P45, which will run many current Intel chips. (Left) I selected the "Celeron" G1610 (2.6 GHz, 2 cores) to run with a "mere" 2 GB of RAM. Choosing the configuration was helped quite a bit by Ars Technica's "Bargain Box" System Guide. My logic was that any new system, even a "bargain" system, would be way better than what I had been using. And that has proven correct.
The hardware change went smoothly enough. The real work (no surprise) was building the new Ubuntu environment with needed development tools and Amateur Radio applications. It will be some weeks before we get all the way back to equilibrium.
Added: I ran the BOINC Whetstone and Dhrystone benchmarks on the G1610 and then on my "big" i7-920 machine. For 2 cores, the G1610 gives 2768 floating point and 16928 integer MIPS per core. For 2 cores (of 4), the i7-920 delivers 2869 floating and 16577 integer per core. So core for core, today's "budget" CPU is comparable to a premium chip of a few years ago. Such is Moore's Law. The '920 will run 8 independent execution threads across 4 cores, giving it 2-4 times more potential in terms of throughput. In practice, that throughput is only realized when I'm cranking 8 threads of BOINC apps, which is a nice thing to do, if your tastes run to extraterrestrial intelligence, pulsars, or gravity waves.
Purists will note that Whetstone and Dhrystone aren't great benchmarks, and I'd have to agree. All I will say is, they came easily to hand, and they're better than BogoMIPS.
Sunday, October 20, 2013
Monday, September 09, 2013
Let's hear it for AM radio!
NYTimes: A Quest to Save AM Before It’s Lost in the Static
http://nyti.ms/1aX6J4Y
Friday, August 16, 2013
So *you* have radio interference problems?
If you want to work at the National Radio Astronomy Observatory at Green Bank, WV (my stomping ground in ancient times), you better be prepared to leave your technology behind. It's a little ironic, because they have some of the most powerful computers, receivers, and electronics you would ever hope to use, but all the local equipment is rigorously RFI-suppressed and tested in anechoic chambers before it is installed.
Check out "The Enemy Is Us" (pdf).
Added: NRAO Green Bank is near the center of the National Radio Quiet Zone. This is a much larger area (13,000 sq. miles) where all radio emitters by law have to be coordinated to minimize impact at NRAO.
Thursday, August 08, 2013
Luddite Cellphone Report
For a few years, I've been telling folks about how I've gone from a $100/mo. smart phone service to $10-15, non contract, on a barebones Tracfone device. I don't need e-mail and Internet connectivity when on the hoof, and I have a Nexus 7 tablet for navigation and portable use. Lately, we've had a weird sequence of events that got me to re-evaluate, but the situation is stabilizing now.
The story outline:
- Noticed that my car's Bluetooth hands-free system isn't functioning. After a few days,
- Leaning over to check my pool water, and my Tracfone fell out of my pocket into the deep end.
- Phone is retrieved after 5 minutes and placed aside to dry out. Not much hope, as my last Tracfone suffered the same fate and never came back.
- Recalled that at least one smart phone is now being advertised as waterproof (or resistant?). Maybe that would be a good one to have? It would be nice to have mobile yelp and other services like my friends all seem to have...
- Trying to do some banking business, I discover that I'm blocked because I signed up for 2-factor authentication. I can't add my wife's phone to the list without receiving a code on my dead phone. (I could call the bank about this, but that's a last resort.)
- Google's 2-factor process at least allows me to use one of my one-time pass codes since, thankfully, I haven't lost my wallet. Anyway, I better get a phone back with my old number asap.
- The quickest and easiest way to get my number working again is to go back to Tracfone. I ordered a reconditioned LG.
- Phone arrives, costing a little over $20 including overnight air. It wants me to charge for "5 hours", but charging is complete after about 2 hours.
- Now to the T'phone website to register the new unit and hopefully snag my old number back. End up with a human operator of uncertain nationality talking through a horrendous phone circuit. She said many things that I did not understand, but finally it seemed we agreed on the basics. (I hope I did not agree to sell my firstborn.) My number should be effective overnight. Actually, it only took an hour or so.
- The new phone became registered in stages. At first, I could dial out, but not receive calls. Then it seemed I could send text message, but not receive them. After 1-2 days, we seem to be fully registered wherever cellphones get registered.
- Car's hands free Bluetooth is still bust. I'm guessing that repair will either be free (find the right reset button) or probably 10X the cost of the new phone.
Tuesday, May 07, 2013
Raspberry/Beagle/Core Benchmarks
Measured the other day using iPython:
iPython's "timeit" function is hardly the last word in benchmarking, but it can be very useful if you're thinking about Python applications. Raspberry Pi is very powerful compared to Arduino, say, but very slow compared to modern desktop machines. No surprises, but I haven't seen relative benchmarks before.
Saturday, May 04, 2013
Lousy Saturday on 40 meters
Solar weather (M class flare) makes the low HF bands very quiet this morning! Some day I have to dig in and understand the scale on this map. It says we're affected by "1 dB" on 40 meters, but I'd say it's more like 30 dB from listening on the band.
Check http://www.swpc.noaa.gov/drap/global.html for the latest.
Tuesday, April 30, 2013
Raspberry Pi - 30X more time for coffee
![]() |
| alliedelec.com |
My Raspberry Pi is benchmarking about 30X slower than one thread (out of 8) on my desktop Core i7 processor. It's an interesting challenge to do real-time Python / wxWidgets programming on the little guy, but we're making progress.
Thursday, April 18, 2013
Cable to U-Verse and back again
Executive summary: AT&T U-Verse out, Comcast cable in.
I've been living as an Amateur Radio operator with AT&T's U-Verse service for about 18 months. It was a great experiment, to see whether ham HF operation could be compatible with U-Verse's VDSL2 signalling.
VDSL2 delivers a bit stream over channels stretching from a low frequency to over 8 MHz, so it was a challenge to work at power levels over 50 W or so in the 160, 80, or 40 M bands. We tried lots of things -- ferrites everywhere, shielding, etc. At the same time, AT&T's technology improved, with higher bit rates and more tolerant modems. We weren't too unhappy as U-Verse customers -- but that was only because I don't spend a lot of time on the air (especially QRO) during TV viewing hours.
Still, I have grown tired of having to think too much about my TV, Internet and phone service. They should just work! Even for radio amateurs. Back to the cable world -- Comcast.
The problems with Comcast will undoubtedly come. Maybe they'll throttle me if I don't watch enough NBC shows. But in 2 years, maybe we'll see Google or Verizon or somebody offering something more attractive? Stand by.
I've been living as an Amateur Radio operator with AT&T's U-Verse service for about 18 months. It was a great experiment, to see whether ham HF operation could be compatible with U-Verse's VDSL2 signalling. VDSL2 delivers a bit stream over channels stretching from a low frequency to over 8 MHz, so it was a challenge to work at power levels over 50 W or so in the 160, 80, or 40 M bands. We tried lots of things -- ferrites everywhere, shielding, etc. At the same time, AT&T's technology improved, with higher bit rates and more tolerant modems. We weren't too unhappy as U-Verse customers -- but that was only because I don't spend a lot of time on the air (especially QRO) during TV viewing hours.
Still, I have grown tired of having to think too much about my TV, Internet and phone service. They should just work! Even for radio amateurs. Back to the cable world -- Comcast.The problems with Comcast will undoubtedly come. Maybe they'll throttle me if I don't watch enough NBC shows. But in 2 years, maybe we'll see Google or Verizon or somebody offering something more attractive? Stand by.
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