Sunday, February 07, 2010

Amazing local publicity

A great local newspaper piece on Amateur Radio, Haiti support, and Harold Kramer, WJ1B. Check out the video, too.

Sunday, January 24, 2010

Wondering about AMPRnet

Do you know about AMPRnet? I've wondered about this mythical network off and on since the 1980's packet boom. Back then, I was doing 1200 bps 2-meter packet from my home in Guilford, CT. I had a nice little setup with a toaster-style Macintosh, a KAM+, and a 10-20 Watt transmitter (Handytalky with an amp.). It would do the usual packet thing -- access local BBSs, digipeaters, etc. With a lot of effort, I could connect through RF gateways into New York or the Boston area. It was kind of fun sitting there and listening to each packet going out and (hopefully) returning. Not useful, by any means, but entertaining.

Then I got the TCP/IP bug. On the one hand, this was a loser for performance, adding all the overhead of full routing to each packet. On the other hand, there was a degree of error control, and I had actual IP addresses assigned to me! I was 44.88.4.9 (aa6e.ampr.org) and 44.88.4.10 (aa6e-1.ampr.org). So far as I know, the IPs are still "mine", but the server ampr.org has forgotten about me. :-(

There is a "Class A" network assignment for AMPRnet or "ampr.org" -- 44.0.0.0, or as we now say in CIDR terms, 44/8. That's a big deal. That is an allocation of 2**24 = 16,777,216 individual IP addresses, about 1/256 of the entire IPv4 address space, assigned to Amateur Radio. That's the same IPv4 address space that is supposed to be exhausted as soon as 2011.

AMPRnet appears to be very lightly administered (and that's being polite) -- even for an amateur radio activity. The allocations are supposed to be managed by regional volunteers, but coverage seems spotty. The advertised coordinator for my area seems to be inactive now, so there is no one for me to even ask about my allocation! And, if you can get a number, it doesn't have much value, since no one can route packets to you unless you make "upstream" arrangements that are impractical for individuals. People seem to set up tunnels to a server at ucsd.edu, which probably works, but is hardly the way to build a big network!

Traditional packet radio has been in long decline, except for special uses like APRS and DX spotting. Newer digital developments, such as DSTAR and HSMM use TCP/IP technology, since it's still the standard for computer networking, and they may use AMPRnet addresses.

What about that 44/8 network? Is there any way, other than history, to justify maintaining that huge allocation in the face of a global IPv4 number shortage? I know of no simple way to find out which ones are allocated. I would be surprised if there were as many as 1,000 in use. Out of 16 million, it's a trivial number.

The simple fact is that amateurs got a Class A allocation in 1992, when people weren't asking many questions and commercial use of the Internet was just beginning. We'd never get it today.

We should ask why amateurs actually want any IP number assignments. Wouldn't we do just as well with a non-routable private network like 10/8? The vision that somehow a random Internet user needs to interact with a random Amateur Radio station is an odd one. If it involves RF transmission, only licensed operators are allowed -- although the status of server based systems like e-mail and the web may be unclear. It's 2010, and we have 20 years of Internet and ham radio development to look back on. Ham digital nets are fragmented and don't talk to each other much, let alone the Internet as a whole. Why do we need full routability between the RF world and the Internet?

The Internet <--> ham model that is working is tunneling through the Internet to interconnect radio devices and computers. Echolink, IRLP, and DSTAR rely on this mode. No permanent ampr.org addresses are required. An RF-to-Internet gateway is generally at someone's house or place of work, where there is a standard Internet Service Provider connection. The gateway relies on the ISP's assigned address, just as we all do for domestic service.

So maybe AMPRnet needs to be put to rest, giving its water back to the tribe. That would make a nice press release: Public-spirited amateur radio operators help the Internet put off catastrophe for 2 months!

Or, maybe I'm missing something important. Let me know in the comments!

Jeff, WA4ZKO, has some good comments here and here.

Thursday, January 14, 2010

Volunteering at League HQ

Here's the scene at the ARRL Headquarters lobby, as seen from the volunteer Tour Guides' nook. We are a lot busier today than normal, because of various committee meetings and other activities around the Board meeting this weekend.

I've been a ham (amateur radio operator) now for 52 years, enjoying many facets of the hobby -- from Morse Code ("CW") to Open Source Software. In the past year, I've been volunteering at ARRL HQ, as a Tour Guide.

Tour Guides are an interesting lot. They are generally retired folk, like me, who have a bit of time available and who have a long involvement in the hobby and a commitment to the League. I see most of them only rarely, since our slots don't overlap. (I have Thursday mornings, if you'd like to drop in.) The League's coordinator, Diane Petrilli, does know how to keep us motivated, with an occasional group lunch, and a certain amount of "swag". Along these lines, one the best benefits is a special discount at the ARRL bookstore.

The real reason to be a Tour Guide, for me, is to meet a very interesting cross section of radio amateurs, along with spouses, friends, and family members. These are mostly "drop ins" who are visiting in the Newington CT area. Generally, they are long-time hams and League Members. Some of them are quite capable of giving me the tour -- and are happy to do so! On the other hand, there are a few who are just getting interested in the hobby and who need some encouragement which I'm happy to provide.

Tour Guides provide an interface between the visiting public and the ARRL organization, so the flip side for us is having the chance to learn what's what at the League itself. Many hams, myself included, have grown up thinking of the ARRL Headquarters as something like the "mother church". The first visit here is like a pilgrimage to hallowed ground, the historic station W1AW, the editorial offices of the publications like QST, and home of many services for members. I haven't seen anyone kneel to kiss the ground yet, but you get the idea.

Another good reason to hang out at HQ is the chance to operate W1AW. It's a thrill to be a "rare one" on the amateur shortwave bands. It's easy to create a "pile-up" of operators wanting to talk to this classic station. Just as interesting is the chance to use your choice of state-of-the-art radio equipment. It's one of the few ways to "try before you buy".

Today, with the Board of Directors in town, there don't seem to be any normal visitors. A good time to meet some Directors, enjoy the Board's snacks and coffee, and pursue the Internet.

Wednesday, December 16, 2009

Hawaii, as you like it.

Checking the solar weather, you will see there has been some real sunspot activity lately. Is that a good enough reason to check out the HF bands? You bet!


There was exactly one SSB signal on 15 meters, and it was Jerry, AH6V on the Big Island of Hawaii. He was a good S7 here in CT, a very steady and clear signal. Turns out he was running 300 W using exclusively solar power! That's remarkable -- an inspiration, even.

We had a pleasant QSO. I was able to tell him about my new solar garden light system that struggles to produce a couple of mA for a few hours after sunset in the New England winter...

Where were all the rest of the Hawaiian hams?

Sunday, December 06, 2009

Yet another clock program

So I was grumping to myself that my nice, big, cheap Timex digital clock wasn't doing the best job for the ham station. I had modified it for 24 hour time, but the 10 hours digit could only provide a squiggle and not a proper "2" for 20-23 hours. That, and it is physically in the wrong place (away from my computer screen) and it doesn't show civil (local) time along with UTC. I've searched for a good hardware solution with no luck.

Then I looked at some of the many Linux clock options out there. None of those was exactly right for me. I wanted digits I could read across the room, but that would fit onto my crowded Linux desktop. Anyway, it's always more fun to use software you build yourself. I pulled out my Python and wxWidgets (wxPython) references and set to it. As with designing and building your own hardware, half the reward is the stuff you learn along the way.

So here is the product. If it looks like it might be useful to you, it should run on any recent Linux system with no hassles. I also checked it on Windows XP and Windows 7 for good measure. It works there, but you will have to download Python and wxPython from the web. (Linux systems like Ubuntu provide these as part of their repository system.) MacOS will likely also support this program.

This is free (as in beer) and open source software, distributed under the GNU General Public License. That means you can download it and modify it to your taste, as long as you are willing to make your improved source available to the community if and when you distribute your new version.

In a future version, it might be worth working on desktop space efficiency. You notice that nearly half the window area is wasted on Gnome's frame decorations and menus. That could be reduced by using "shaped" frames at the cost of complicating the code and creating non-standard window behavior.

Thursday, November 26, 2009

Why Linux/OSS for Amateur Radio?

How to explain to a non-computer-geek ham what Open Source Software and Linux are all about? OSS and Linux are important to software users the same way a good repair manual and schematics are important to hams. Not every ham knows what to do with schematics, but those who are inclined to open up, understand, repair, and modify their equipment certainly do. Without being able to see what's inside and what connects to what, there is very little you can do. That's exactly why you need to be able to access and work with source code when it comes to software.

These issues will directly affect relatively few hams. Many are "appliance operators" when it comes to software, just as for hardware. For them, a proprietary OS may be a good choice because of its familiarity and the huge choice of available software.

We can admire the dedicated hams who build their own stations and who are on the cutting edge of new hardware technologies. It's the same with software. With software becoming increasingly central to amateur radio (in SDR, digital modes, etc.), competence in coding is getting to be just as important as operating a soldering iron.

While you can roll your own software from scratch, it can be far more efficient (and -- as we like it -- cheaper!) to build your code in the OSS "ecosystem", making use of many libraries and tools that are free for the download. OSS really pays off when you give the fruits of your labor back to the community to spur further development.

These are a few of my open source thoughts!

(a comment on a Linux Journal blog)

Wednesday, November 04, 2009

AC plugs around the world

If you've traveled around the world at all, and you're a ham operator, you've surely wondered about all those different AC power plugs. So who has the best? We have a view from the UK here.

Naturally, the UK wins! I can sympathize with the safety advantages: fusing in the plug and automatic shutters in the socket. (This is for a "manly" 240 V, you know.) But the authors don't consider a few other questions: cost, size, and weight, for example! Those plugs are heavy, bulky, and expensive. The wall sockets take a lot of area for each power point. Don't even ask about outlet strips or "cube taps".

Monday, October 12, 2009

My New "Boonton" Model 59 GDO

Here is my big acquisition from the Nutmeg Hamfest this weekend. It is the classic Measurements Corp. Model 59 Megacycle Meter. Some of us would know it as the "Boonton Grid Dip Oscillator." From what I've been reading, a variant of this unit was first produced in World War II. The manual, available here and here on the Internet, bears a 1947 date. The company was sold to Edison in 1953, so this unit was probably produced in the early 1950's. (The meter/power supply unit is serial #750, the oscillator head is #695, the coil set is #734.)

The developer was the well-known engineer Jerry Minter. (See his IEEE.tv interview that prominently shows the Model 59.) His was one of a number of instrumentation companies active in Boonton, N.J. after the War. There was no connection to Hewlett Packard. (An impression I had at one time.)

I used a Model 59 extensively in the 1960's and 70's, but I did not know that it was a classic even then. Now, it's very satisfying to have my own! It is far superior to the Heath GDO and tunnel diode dipper that I have also used. I see one advertised at $75 on E-Bay, but I got mine for about half that.

The grid dip oscillator is a very handy item for generating signals, checking for resonance, and making rough frequency measurements. This one covers the range 2.2 to 420 MHz in 6 bands.

[Click photos for more detailed versions.]

It is necessary to inspect all new equipment here at AA6E. (The unit was in remarkably good condition. It worked the first time and only needed a little cleaning.) This device had wonderful "build quality" -- as we say these days. The important part is the tunable oscillator assembly, which is meant to be hand held. The inner works are all gold plated (!) and very sturdy. A single 955 "Acorn" triode tube is the active element. Lead inductances are kept very low to allow UHF operation.



Dial calibration is meant to be quite good. Each unit's coil set is supposed to be calibrated to work with a specific oscillator head, although my coil set's serial number doesn't match my oscillator. The tuning "feel" is very smooth.



The power supply uses a 5Y3 GT rectifier and an OD3/VR150 voltage regulator tube. The red filaments and the purple regulator discharge, along with the incandescent (!) pilot light, are a treat by themselves. Not shown is the neat wiring harness beneath the power supply chassis.



Now I need to build another RF gadget!

Sunday, October 11, 2009

Nutmeg Hamfest 2009

The Connecticut Nutmeg Hamfest for 2009 went on in glorious fall weather on October 11.
Note: Click on photos for more detail.

A hamfest always begins with checking out the competition's mobile installations. Relatively few HF installations compared to Dayton.


Always enter by way of the flea market to see what's up. People noted that the larger stores and manufacturers were absent this year. There were still a lot of "mom and pop" flea market vendors.


This was the ARRL Connecticut Convention. Left, our Director Tom Frenaye, K1KI. Right, Section Manager Betsey Doane, K1EIC.


A small, but engaged audience for the League Forum.


Joel Hallas, W1ZR, gave a popular talk on multiband antennas. Guess which favorite antennas really don't work very well on the HF bands!

Another rapt audience.


The flea market had some beautiful nostalgic equipment on display. No, it wasn't selling very fast, but it was nice to look at and reminisce. I got a Boonton grid dip meter, just like the one I used 35 years ago!


The Shore Point club (West Haven) had its very snazzy emergency communications trailer on display. It doesn't look like it's worked through many disasters yet!


The Shore Point trailer command desk. Two people, five microphones, and then some.



I thought this was the highlight of the show. It is W1RT's HF - 10 GHz hill-topping van. An amazing collection of gear, all oriented to VHF, UHF, and microwave contesting.


Overall view of the vehicle area. There was also a converted ambulance from the Danbury group.

I didn't know they gave license plates for Unix veterans, but here is one I found:

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