Friday, February 16, 2007

New Rigserve Project on Sourceforge


Some of you know that I've been working on "Rigserve", which is meant to be a much streamlined server-style application providing much of the functionality of Hamlib. We avoid most of the cross-platform problems by defining our API over an IP connection, which is human-readable and even testable over Telnet. Rigserve is implemented in object-oriented style using Python, which should allow it to run on many platforms. I am not sorry to jettison low-level C, the GNU Automake stuff, SWIG, and all that!

We have talked about the relationship of this development to Hamlib. Should we think of it as a candidate for "V2 Hamlib"? Well, Rigserve is not a library, and there is no backwards compatibility. Rigserve does share some philosophy with Hamlib, but that's about it. I have concluded that it should stand on its own, but we should give full credit to the many folks who have brought us Hamlib as we have it today.

[There are some alternate approaches, too, such as XML rigCAT descriptions at http://w1hkj.com/xmlarchives.html . These may be useful to both Hamlib and Rigserve down the road.]

There is now a project at http://sourceforge.net/projects/rigserve with a slightly updated version 0.21 available for download. The files are managed in the Subversion (SVN) repository.

I would welcome anyone who wants to contribute to rigserve to join this project. There shouldn't be a conflict of interest here, because the intersection of hotshot C and Python programmers is probably limited. Though I am neither(!), I will continue to support the TenTec Orion for Hamlib.

It has been interesting to start a Sourceforge project and to learn Subversion and the other tools. Frustrating, too, because SF's shell server and compile farm chose this week to go into meltdown. The project web page is at rigserve.sf.net.

73, Martin AA6E

Upgrading the Blog

I finally made the leap into the new Google-authenticated scheme on blogger.com. It was a good thing I did, because I found quite a number of user comments for the blog that were pending. All moderation requests were going to an obsolete email address.

Apologies to readers who made great comments along the way. They should now be posted.

-Martin

Thursday, December 07, 2006

Experiments with picopower

On a recent evening at the W1YU Club at Yale, we had a program on QRP operation. That got me thinking. What equipment do I have for QRP work?

Well, I have an Elecraft XG-2. It puts out a fairly well calibrated 50 μVolts into 50 ohms. That is about 50 picoWatts on 20, 40, or 80 meters.



So here is my QRP transmitter. All it needs is a CR-2032 battery. I find it is tricky to send CW with the power switch, so I attached an old straight key. The coax goes to a 3-element SteppIR at 40 ft.

What can we do with 50 pW on 20 meters? First, try listening for it on my main rig, the Orion using a 40 M dipole. There it is, about S2 on 14.060 MHz. It is stronger if I aim the beam south, toward the dipole.

I tried a quick "CQ" just in case... But the band was dead. No response, no surprise!

Next I tried using my Icom R8500 set up temporarily in the car, with a 15 foot wire strung out over the trunk. The '8500 is not a great CW rig - it doesn't even have the narrow filter, but otherwise it fills the bill.

First test: yes I can hear the signal in my driveway, about 60 ft from the beam. I drove away to a point about 300 M away and gave a listen. (Auto noise was hopeless - I had to shut off the Acura completely before I could get near the noise floor.) Nothing at 300 M. Drove closer and closer, but still nothing positive. Finally, the signal was there at S1 about 2 houses away from mine -- maybe 50 M. It would have been usable for a QRS CW QSO.

(If we had a more appropriate receiver filter system and receive antenna, we might have gotten 10 dB more sensitivity.)

OK - if 50 meters is the range for 50 pW, what can we calculate? How about if we had 50 microwatts instead? That's a million times more power, and the square root of a million is 1,000. (We assume the inverse square law works, although really we're in the near field at only 50 M separation.) So what range would we expect for 50 μW? A thousand times more -- 50 kM or about 30 miles, at least for free space line of sight.

One day, I may throw together a 50 μW "QRO" rig to check this prediction.

Another calculation: 50 M is 28.6 milli-miles, so we have 571 million miles per Watt. It wasn't a two-way QSO, but would this be a record?

[Miles per Watt, as others have noted, is a nonsense ratio. For a constant signal to noise ratio, "miles" will vary with the square root of power, not linearly in power. In other words, the record should go to the QSO with the highest "miles per square root of Watts".]

[5/22/08: Photo restored.]

Friday, November 17, 2006

Known by the company we keep

I see we made the big time with a listing in AwfulBlogs.

You know what the doctor says, when you say "it hurts when I do this"? He says, "well then don't do it any more."

Moving on...

Rigserve

Rigserve is a new approach to local and remote control of ham rigs, inspired by work on Hamlib. Rigserve is an IP network server, programmed in Python, that provides a simple text-based interface to control an arbitrarily large number of rigs. The code is compatible with Linux-like OSs and Windows. Rig backends are provided initially for the Ten-Tec Orion (I and II) and the Icom R8500.

See hamlib-developer.blogspot.com and www.aa6e.net/aa6e/software for more information.

Saturday, September 30, 2006

Hamlib, reloaded

The Hamlib project has been working on a rig-independent API for software developers that will allow them to connect to a wide variety of ham rigs without worry about their individual interface quirks.

Lately, we have begun discussing how this project can envolve into a "version 2". There is a new blog at hamlib-developer.blogspot.com to support development of Hamlib. If you want to take an active part in the Hamlib project through this blog, please contact me.

The Hamlib project is supported at sourceforge.net/projects/hamlib, which provides a mailing list, CVS, and other amenities.

DXCC at last?

After some 49 years in amateur radio, I tallied up my QSL connection and found 101 "entities". If the League agrees, there will be a new piece of wallpaper for me - DXCC. At this pace, I will be on the honor role in about 150 years.

Thursday, September 21, 2006

ARRL LOTW on Linux Fedora Core 5

If you're a hard-core Linux ham and you want to use the ARRL's "Logbook of the World" (LOTW), you are in for some work. The Linux binary software distribution is provided only for Fedora Core 3 distribution, which is now well out of date. You have to compile from source code, and even the source code is out of date with respect to current (Fedora Core 5) compilers and libraries.
Here is my cookbook recipe for how I did it on my FC5 system. I believe I've incorporated all the steps, but I would welcome your feedback if you try to replicate the results.

Fedora Core 6 is right around the corner, and FC6 may possibly require further modifications.

Added Note: The procedure has been found to work as recently as the Fedora 8 release. (12/2007)