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Saturday, February 28, 2009

Out of the Ozarks... The NS-40!

I think this new rig is really interesting. NS stands for "No Simpler." It has only 14 parts. The coils are etched into the PC board (see above) -- I've never seen that before in an HF rig. It runs Class E and puts out 5 watts! The Designer is David Cripe, NM0S, and a kit is available from the 4 States QRP Club for only $30. Look here for more details:
http://www.wa0dx.org/wa0itp/ns40.html

Friday, February 27, 2009

Out of the Sonoran Desert... The Gnat!

We've been away for a few days, down in the shadow of Vesuvius, but I'm back in the shack now, and this morning I've been looking more closely at the latest creation out of the Sonoran Desert:
Chris Trask, N7ZWY, has given us the design for an amazing rig he calls "The Gnat" (Chris has a deep interest in the flora and fauna of the Sonoran Desert.) Like the ET-1 and FETer, The Gnat is an HF transceiver using only one active device. Chris uses a 2N2222 transistor. But unlike the other one-device rigs, The Gnat uses no switches or relays for T/R transitioning -- his rig goes from Receive to Transmit just by pushing the key down. The receiver is, of course, a regen. And get this: The Gnat can produce somewhere in the area of .5 watts to 2 watts of RF. Wow, that's one big bug! There's definitely a lot of Knack in The Gnat. Check it out:
http://www.home.earthlink.net/~christrask/Gnat%2040.pdf

Monday, February 23, 2009

QRSS on HACK-A-DAY

Eliot over at Hack-A-Day was kind enough to run an article about our QRSS exploits. I figured this aspect of the hobby would be intriguing for the more computer oriented folks who visit that blog. Judging from the comments, I think I was right.
Check it out:
http://hackaday.com/2009/02/22/qrss-radio-amateurs-slow-speed-narrowband/

Sunday, February 22, 2009

Happy 6L6 DAY!

Cory, WA3UVV, sent in this nice article about a beloved vacuum tube:

Say "73" to the 6L6


Sometime in the spring of this year, the 6L6 will celebrate it's 73rd birthday. Originally conceived of a year earlier by engineers at General Electric, it represented a new design in receiving tubes (more about that later) and used the recently developed metal case(envelope), instead of glass. RCA was licensed to manufacture it and the first ones hit the market in 1936.

Originally thought of for audio use, it could give you 30+ watts of RF if used in a single-tube oscillator circuit. Not bad for a "receiving" tube - a general name used for things that were "low power" when thought of in comparison to broadcast radio transmitter power levels. It quickly became the most popular tube for ham transmitters for many years to come.

In a fairly short period of time, the 6L6 was also produced in a variety of glass envelopes. In fact the basic 6L6 went through many changes and upgrades as it went through life. RCA moved the plate connection to the top and the 807 was born. This power house, when given 600 volts on the plate could manage 60 watts without breaking a sweat. So much in use, the term "807" was once a popular ham nickname for beer. Technology marches on, and eventually the 807 was succeeded by the shorter 6146. The 6L6 saw it's life increased as the 6LQ6. Both of these tubes were quite popular, as well. Used in sets in kilowatt-level amplifiers with over 1,000 volts on the plates, they also showed up in pairs as finals in hybrid rigs in the 70's. I have a Handbook from 60+ years ago with a circuit for a one-tube 6146-based, 75 watt crystal-controlled transmitter. Don't try that with anything less than a FT-243 crystal...

The 6L6 also had lower rated siblings, the 6V6 (popular with Novices and used in some commercial designs like the Ameco AC-1 transmitter kit) and the 6K6 (very QRP-friendly). "Circle of Life" fans will note that 6L6's still enjoy use everyday, although primarily in audio amplifiers for those who like the glow and "warmth" of the the sound. You can find them at music stores for $50 a pair and up or at hamfests and Ebay for much more reasonable prices.

While I don't know the exact date the 6L6 arrived, March 14th is the 73rd day of the year. There's still time to celebrate the 6L6 by building a rig and putting it on the air that weekend. A straight key is strongly suggested. A quick perusal of the League's searchable QST database (you are a member, aren't you?) will turn up many design ideas and possibilities. Even if you don't have a spare 6L6, 6V6, 6K6, etc. to play along, they're easy to find. (In fact, I'm sure I have a spare for someone who wants to build his own rig in the coming weeks.)

Power supply? A 6 volt filament supply is easy - you can even use some wall warts for that. Coming up with 150 to 600 volts may be a bit more daunting, but if you have a tube-based receiver (makes a nice companion) you can carefully borrow some B+ for a low-power version. Or, go to the "everything we sell is a dollar, so please don't ask how much it is" store and pick up some 9 volt batteries. If you buy 15 packs of 2, you can click them together and come up with 270 volts for (wait for it) $15.

Hey, don't touch the ends to see if it's hot - it's still 270 volts and is dangerous if not respected! Pick up 15 more packs and you'll have a real rock crusher on the air.

If you've never gone on the air with tubes, here's a fantastic opportunity to mark "73 to the 6L6 Day" (or something like that). Remember, real radios glow.

Saturday, February 21, 2009

W3JDR 's LTSpice NE602/SA612

Here's something we've needed for a long time: an LTSpice model for the ever-popular NE602/SA612 chip. Joe Rocci, W3JDR, developed this one back in December. You can download it, along with the LTSpice program (free!) from links on Joe's page:
http://w3jdr.ham-radio-op.net/ Thanks a lot Joe!

Speaking of Spice, Jim, AL7RV, has been e-cursing me for getting him involved with this highly addictive program. Jim has come up with an ingenious idea for making the simulation experience more realistic. I will tell you all about it in the next podcast.

Friday, February 20, 2009

The Reggie Works a DX Station!

There it is. Finally we see it. The famous Reggie of AA1TJ. With an awesome 80 milliwatts of 80 meter RF, Mike yesterday worked the Bahamas with his highly unusual rig. For more details visit Mike's always inspirational web site:
http://mjrainey.googlepages.com/reggie

Wednesday, February 18, 2009

WA5DJJ's QRSS Beacon: Immediate Success!

Here's a story that really captures the fun of QRSS, the way in which this mode can be both high tech/DSP-ish and low tech/minimalist at the same time. It also shows the global reach of the fraternity that supports QRSS. In SolderSmoke 101 I reported on the QRSS building project of Dave, Wa5DJJ. He was building a rig based on a design by the esteemed Maltese radio wizard Stan, 9H1LO (Stan appears in the SolderSmoke slide show -- he is the guy in the lab coat.) You'll recall Dave's comment on how upside down FSK might be useful in reaching our brothers "down under." Yesterday Dave put his new creation (see above) on the air, and posted a message to the Knights of QRSS Yahoo Group. In Belgium, Johan, ON5EX, saw Dave's message and decided to check W8LIW's receiver (via LIW's online grabber). Johan saw Dave's signal and reported the success to the Knights.
You can read more about Dave's project here:
http://www.zianet.com/dhassall/QRSS.html

Here is the e-mail exchange between Dave and Johan:


Tuesday, February 17, 2009 7:46 PM
From:
To:
knightsqrss@cnts.be

Hi Dave, I can see your sigs are on the Ohio W8LIW grabber right now, with a little downward shifting. Well done! Your website truly reveals a keen QRP-er and homebrewer. BTW: I’ll be firing up my first RockMite (20) soon! 73, Johan on5ex


From: knightsqrss-bounces@cnts.be [mailto:knightsqrss-bounces@cnts.be] On Behalf Of David R. Hassall
Sent: woensdag 18 februari 2009 1:30
To: knights QRSS
Subject: [Knightsqrss] WA5DJJ on the air!!

Dear Gang,

First test of my QRSS 10.140Mhz MEPT. It should be around 1.060 on the waterfall. Power output is 122mW (All I could squeeze out of my poor little 2N222A final. Keying is up shift, at about 5 hz. I hooked it to my 30 Meter Inverted Vee off my tower. Apex is at 40 feet. I think I have it right and hope it doesn't blow up. We shall see when I get some reports. I will have pictures on my website as soon as I can get them there. Thanks for all the advice and help. This was a really fun project. Now to get a couple more built to get some others on the air.

73 Dave

------------------
BTW: I succeeded in putting Johan's grabber output onto this blog. Look at top of my right-hand column. If the sun is up over Europe, you should see my upside down FSK around the middle of Johan's screen. (He has the screen kind of split in two to allow more minutes to be displayed, so you should see me in the middle of both the top and bottom halves of the screen. ) You may have to hit the refresh button on your browser to get my blog page to pull down an update of Johan's grabber. Just think about how cool this all is: I transmit a 50 mw sig from Rome with a very minimalist rig. Johan receives it in Belgium using DSP software and puts the results on the www. I embed his output screen on my blog, which you can now see, almost in real time!
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column