I know some guys are just not into homebrewing, but with the construction techniques on the Circuitry Snacks Web page, everyone can become a builder. Even if you don’t own a soldering iron!
At the Hands-On Musuem, we’ve been having some trouble with our signals getting into some cheap computer speakers that one of the staffers has connected to her computer. I Googled to see if I could find any information on this, and came across a reference to some computer speakers that West Mountain Radio sells that are supposedly RFI-resistant.
I e-mailed them, asking if they might be able to tell me what they’d done to improve the performance. Here’s their reply:
We are sure you can find a great deal of information in the ARRL Handbook about making equipment, that has to exist in strong RF environments, immune to that RF.
I the case of the computer speakers we designed and have available for sale in our line of quality Amateur Radio Products, we have applied some of these techniques and some of our own. However because we designed these as products in our continuing attempts to remain in business by making a profit (as slim as it may currently be) we do consider this to be Confidential Intellectual Property and as such we are unable to be anymore specific than this.
Thank you for your interest.
Sales & Support
West Mountain Radio
This response really turns me off. I could maybe see them responding this way if I was asking for some super-secret DSP algorithm or something like that, but as K3EIN points out, this information is readily available. It’s certainly not rocket science. Anyway, this makes me kinda not want to buy anything from West Mountain Radio again.
Charles Osgood, a national news commentator for CBS Radio, commented last week on our current lack of sunspots. He says,
The Sun normally undergoes an 11-year cycle of activity — and last year, it was supposed to have heated up — and, at its peak, would have a tumultuous boiling atmosphere, spitting out flares and huge chunks of super-hot gas.
Instead, it hit a 50-year low in solar wind pressure, a 55-year low in radio emissions, and a 100-year low in sunspot activity. Right now, the sun is the dimmest it’s been in nearly a century.
If you’ve been on 20m lately, you already know that, though. To hear or read the rest of his commentary, go to The Osgood File website.
Samuel F.B. Morse was born on April 27, 1791 in Charlestown, MA. Google, never one to miss a beat is commemorating Morse’s birth today.
Yesterday, Bruce, KD8APB, and I held another one-day Tech class. This time, however, only eight out of ten passed the test.
The two that failed, were a teenager and his grandmother. I was afraid that this might happen. Teenagers just don’t seem to do very well with this format.
I think part of the problem is that because the training is so intense, the students really have to stay focused. Kids, being kids, are not usually that focused. I’d be interested in hearing from any of you out there who have had more experience with teenagers.
Thanks to the VE team: Clay, W8JNZ; Roger, W8ZRF; Ralph, AA8RK; Rane, N8REG.
The latest buzz on the Glowbugs mailing list is about the sale of a Weskit BN-1. This rig, apparently sold by Western Radio of Kearney, NE is a one- or two-tube “Novice transmitter/receiver.” It originally sold in kit form for $14.95, assembled and test $19.95.
Sheldon, KC0CW, actually has a very nice writeup, which includes a schematic, about this radio. In part, he writes:
The Weskit transmitter-receiver was made by Western Radio (a.k.a. Western Electronics) of Kearney, Nebraska, around the 1956/1957 time period. It is an extremely simple rig, using only a single 7 pin miniature type 3A5 tube. This dual triode tube, which typically serves as a push-pull audio output tube in battery powered portable receivers, performs the transmit function with one triode, and the receive functions with the other. The front panel as shown above, is made of thin sheet metal, with a rather attractive gray paint job with red screen printed markings. The sides, top, and bottom of the box are made of a plastic impregnated cardboard, while the back of the unit remains open.
The transmitter is a modified Pierce crystal controlled oscillator on the 80 or 40 meter amateur bands. The L-C tuned plate tank circuit is link coupled to the antenna, and a type 1843 incandescent lamp in the antenna circuit is used as a tuning indicator. After tuning, the lamp is to be replaced with a type 41 lamp to reduce resistive losses. Power input can be as much as 5 watts with 180 volt supply, however the instructions suggest plate supply voltages as low as 45 volts, with “nominal” operation at 90 volts, with about 1 to 1.5 watts input. Snap on clips are provided for connection to dry cell batteries for high voltage, and a single D-cell battery holder is provided for the filament supply. Switching from transmit to receive applies filament power to only the half of the tube which is in operation.
The receiver is a regenerative type. Regeneration is controlled by a potentiometer across the feedback winding of the tuning coil. Frequency coverage is claimed to be 3400 kc to 8000 kc in the manual, however dial calibration does not go below 3500 kc. Audio output is intended to be fed to high impedance headphones. An optional stage of audio amplification using a type 3V4 tube can be added for operation of a small speaker. A pre-punched hole in the chassis can be utilized for the purpose of mounting the additional tube.
As you can imagine, comments were mixed.
One guy commented, “What a cutsy-kewl rig; and it’s DC powered to boot!”
Another replied, “I remember seeing an ad for the bn-1 when I was a novice and taking offense at the word ‘novice’ emblazoned on the face of the poorest excuse for a lunchbox with knobs I had ever envisioned. I still think that abomination was designed and marketed as a joke. I just cannot imagine any sane ham buying, building, or even wanting something that crude. The folk that brought that thing to market were confusing the words amateur and fool.”
A third said, “The thing with such gizmos, like the one-transistor radios and such that were advertised in the same era magazines, is not to expect miracles for your money. That the ad was the size of a postage stamp should be a clue to any reasonable reader that you were not dealing with the National, Hammarlund, or Hallicrafter class. The thing does work, whether you like it or not. What’s not to work?
“A 1-watt transmitter and a 1 or 2 tube receiver. Granted, the
tuning rate is atrocious, but it was intended to just tune to the frequency of the crystal.
“I prefer to consider such gizmotron products as kind of a friendly joke. The buyer understands, somewhere in his head, not to expect miracles, but you can still hope for them. The company provides a not-expensive learning experience (and I don’t mean learning about being ripped off!! ) and makes a little money as well.”
It does kind of amaze me that someone would actually buy one of these things, but as the last guy says, you could get them to work, and if they weren’t stellar performers, they were cheap, so it was an inexpensive education.
Here’s an interesting post to the GlowBugs e-mail list from Jason, KF6PQT. The subject is, “I think this Ham Radio nonsense might have finally paid off!”
In my 13 years since graduating college, (mind you, I have a Liberal Arts degree in Philosophy, um, yeah, one of those… It cost a lot more than it was worth!) my career has been IT stuff—tech support, Systems Administration. All computer related, as that and the Internet was the sexy new “high tech” back then. I later specialized within the Entertainment Industry, mainly with Disney. Which, as you may have heard, isn’t really the happiest place on earth to work.
I’ve been on their “revolving door” program, full time employee laid off after 3 years, then returning for various stints as a non-benefitted, expendable contractor
I’ve been out of work since last August, part of that was due to slacking off, some more due to the crummy economy, and the remainder: I simply came to hate my career after a while, and especially the industry I was in. I recently realized that a big reason why I was still unemployed was that I simply didn’t want to do this sort of work anymore, and therefore I was simply not pursuing it at all. Likely a lot of the reason I was let go (aside from making way more $ then they wanted to pay me) was that I knew exactly how much of a POS my project was, and there was absolutely no way I could ever be a cheerleader for it, under any circumstances, even though the only reason it worked at all was my 2-1/2 years of hard work.
What else to do? Why can’t I get work doing what I do for a hobby? No one wants to give me a job building CW transmitters out of discarded TV sets. ;) Finding a gig as a babysitter for a broadcast transmitter would be awesome, but those jobs are extremely scarce. Even if they still needed CW capable radio offices on ships, I don’t think my girlfriend nor family would be too fond of it. (Even if I was issued my own AK-47 with handy clip-on grenade launcher.) I’ve even pondered applying for a Lineman position with my municipality’s electric Co. 12kV? Heights? Not a problem. Sun damage or skin cancer from working outside all day? Might be a problem.
So I got up late this morning, and over my morning coffee looked through Craigslist, saw a job for an electronic testing technician. Sent ‘em an email with my resume, saying why I’d be a good fit even though I have absolutely no career experience doing this—I’ve got the highest-level Amateur Radio license, like to tinker with electronics and troubleshoot, etc.
I got an email back pretty quick asking when’s the soonest today they could meet me! I spent almost two hours chatting with them, and seeing what the testing techs do.
Got a phone call earlier this evening offering me the job! Of course I accepted, got them to bump the pay rate up a tad too, and got them to let me take the vacations in May and June I’ve been planning since last year, also. I won’t make as much as I used to at my last IT job, but its not bad for pretty much a total career change with no formal experience. And it sure beats the unemployment check and hustling scrap metal!
This company makes 100% accurate reproductions of airplane cockpit instruments for flight trainer/simulator systems. Most of it all are LCD displays, but there were a couple of little CRTs being worked on as well! ;)
That, and getting my CA state income tax refund, (miracle in and of itself!) has made for a pretty good day!
73, Jason kf6pqt
Here’s another card to add to my collection of QSLs from stations whose callsigns spell words:
Thanks, Bill. This is the first time that I’ve been HEXed over amateur radio.
I also recently worked a couple other relevant stations: K0OR and N2OH.
From the IEEE website:
Communications-frying e-bomb might be part of a stable of “less lethal weapons”
15 April 2009—This week at an arsenal in Huntsville, Ala., defense researchers are testing a new high-power microwave (HPM) bomb—one that creates an electromagnetic pulse capable of disabling electronics, vehicles, guided missiles, and communications while leaving people and structures unharmed. The tests mark the first time such a device has been shrunk to dimensions that could make it portable enough to fit in a missile or carried in a Humvee or unmanned aerial vehicle.
IEEE, the world’s largest technical professional association, has awarded the HP-35 Scientific Calculator with the prestigious IEEE Milestone in Electrical Engineering and Computing award. The designation was awarded on April 14, 2009 and an IEEE Milestone plaque recording the award will be permanently displayed at HP Labs in Palo Alto, CA, the site where the HP-35 was originally developed.
The Web page commemorating this award has all kinds of info on the HP-35, including a video and photos.
Just to show how old I am, the HP-35 came out my senior year in high school. When I got to engineering school the next year, several of my fellow students already had one. I waited until Texas Instruments came out with the SR-50. The SR stands for “slide rule,” as in “electronic slide rule.” The HP-35 cost $400, and the more advanced HP-45 a little more. The SR-50 cost $250, and as far as I could tell did everything that the HP-35 could do.
I actually still have my SR-50, although I haven’t used it in years.