Saturday, February 28, 2009
Friday, February 27, 2009
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:
Monday, February 23, 2009
Check it out:
Sunday, February 22, 2009
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 , 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 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 . 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
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
Wednesday, February 18, 2009
You can read more about Dave's project here:
Here is the e-mail exchange between Dave and Johan:
Tuesday, February 17, 2009 7:46 PM
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: On Behalf Of David R. Hassall
Sent: woensdag 18 februari 2009 1:30
To: knights QRSS
Subject: [Knightsqrss] WA5DJJ on the air!! [mailto:email@example.com]
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. 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.
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!
Monday, February 16, 2009
I continue to work on my regen (part of the ET-1/FETer minimalist project). Jim, K9JM, says the raspy tone on CW signals is caused by FMing of the regen stage and prescribes a coil of higher Q. Thanks Jim.
Sunday, February 15, 2009
http://www.soldersmoke.comFor the podcast go to:
Superbowl Sunday in Rome. "Playing for Pizza." Spirals on the Piazza
Empire of the Air -- Gerbils Renamed
"Electrons on Parade" Good RCA film about tubes
ET-1/FETer transmitter built -- some problems
New Minimalist Yahoo group
AA1TJ and AA1MY make QRP History with tunnel diode rig
New beacons and grabbers in US and Canada
K6HX and the lure of the whisperers
Upside down FSK for VK/ZL observers?
Chip extraction tips (belated)
What "s.o.t." means.
Brad WA5PSA still jogging in Tulsa
Ted AJ8T and Paul VK5PH: Lake not named for Lee
Neil G7AQK HB mystery box
Doug WB5TKI on how to extract chips
Ron AA5RS advises Billy to stick with Linux
Bill AA0RQ uses the hard stuff
Scott on Heaviside: Good guy or not?
Brent in Twin Cities: SWL Rockmite and SS lead to ham radio
Dan NM5DV building SDR QRSS rig
Jeff K07M listens while flying private plane
John W6TC has great article for Electronic Design
Edwin WA4YHL: Amateur Logic TV #23 is available
Dale WA5DJJ on the possible benefits of upside down FSK
Eddie G3JZO: Upside down FSK looks like laundry on the line!
Jerry NR5A has the minimalist bug
For the new SolderSmoke Store:
Saturday, February 14, 2009
Here's the article:
No need to move. They do mail order:
Looks like they are having a Vintage Radio event on Feb 21, 2009
Friday, February 13, 2009
You should also visit John's personal web site. We're about the same age, and we are both from New York City. John's page reminded me of another factor that might have put me on the path to solder smoke and hamfests: The 1964 World's Fair. Here's John's page:
Wednesday, February 11, 2009
Tuesday, February 10, 2009
In related news, Jerry, NR5A (who has also been bitten by the minimalist bug) reports the creation of a new Minimalist Radio Yahoo group:
(Jerry and I have been attempting to translate some technical terms found in British schematics. Even though I lived there for four years, I admit to being stumped by "s.o.t." given with values for capacitors. Could this be "subject of test"? )
Sunday, February 8, 2009
Gee-willikers! This RCA movie is the cat's pajamas! Really great stuff. The guy who posted it on YouTube said it had been sitting on his shelf for years, apparently just waiting patiently for the broadband Internet.
I hadn't realized how labor intensive tube production was. Looks like every one of those fire bottles was, to a large extent, put together by hand. The contrast with the way solid state devices are produced is really striking -- the tubes seem like the product of artisans. And they somehow just seem to be more homebrew-friendly than modern solid-state devices.
Don't miss Part 2! Here we see "heroic hams" in action, saving people from serum shortages during floods, etc. Watch the policeman with the Tommy-Gun almost run over the kid on the bicycle. Yikes G-man, that was close!
The date on the film is 1942, and judging by the number of women shown working in the factories it does seem like a wartime film, but I was surprised by how infrequently the tube's role in the war effort was mentioned.
Saturday, February 7, 2009
Be sure to check out Michael's description of the rig:
Also, don't miss the pages on Reginald Fessenden:
Seab, AA1MY sent me a message just over an hour ago saying that he suddenly began hearing my Mikums transceiver running as a beacon! Seab lives in Bethel, Maine, an air distance of exactly 100miles/160km from my QTH. A few hours earlier I'd measured Mikums' output power at 169uW (yes, microWatts!).
I was at the computer when his message appeared so I quickly called him on the telephone. He said that he'd been monitoring while he was busy with some paperwork. He'd just returned from fetching a load of firewood and all of a sudden there I was! He put the phone near his loudspeaker and I just about fell over! I was weak, but perfectly readable.
Then I practically hung-up on the poor fellow in order to race down to my shack in order to try for a QSO. I heard him clear as a bell at a power of 40w (I reported 459, but I ought to have sent 559). He confirmed my report and then dropped down to 4w. Although weak, I easily copied his 429 report to me. I gave him a 219, which he confirmed.
Oh boy...it's done. We made a skywave QSO using a one-tunnel diode transceiver. I'm practically giddy here :o)
Many thanks to Jim, W1PID, who has patiently listened for several days. In fact, Jim has copied my CQ and callsign several times before my signal evaporated on a breeze of QSB. In return, I copied Jim's Small Wonders Labs DSW at 2w on Mikums with no problem the other day. Again, many thanks, OM. The next time we meet, I'm buying, okay?
Again, way to go Seab; that's one small step for man....naw, more like one more exciting and thoughly useless (ain't it great!) milestone in the history of QRP :o)
73/72's all around,
Thursday, February 5, 2009
One of the many interesting things found via the AM Window is an on-line archive of the AM Press/Exchange newsletter. There are some very good articles in there. Issue #114 has a good one by George, W2WLR. It's about lightning and ways to prevent strikes. What I like about the article is the very practical, hands-on approach. George describes how one intrepid enthusiast put an amp meter between a radio tower and ground and watched the currents generated by a nearby storm (don't try this at home!). The article discusses how brushes on the ends of lightning rods help bleed off charge. You can see some charge bleeding off the masts of the ship depicted above.
After reading his article, I went to work. In an idle moment, I looked out the window across Rome's Via Veneto and saw on one of the hotels some lightning rods tipped not quite with brushes, but with multiple spikes. Go St. Elmo!
Wednesday, February 4, 2009
Today, Mr. Rector, Paul, and I went out to Radioworld and purchased a transceiver. After much research, we decided to go with the ICOM Ic-V8000. For the cost, it has exactly what we need. On Friday, we're going to be integrating it into our setup, and doing all the necessary testing.
This contact was no big deal really. When I was talking to Norm Thagard on MIR station back in the 20th century, there was one 13 year-old kid in South Africa who pulled off the same feat.
See: http://www.gadgeteer.us/MIR18.HTM If they had actually built the radios themselves it would have been a bit more noteworthy. Looks like this one had more PR smoke than solder smoke.
Tuesday, February 3, 2009
Read more about OM Grote here: http://www.nrao.edu/whatisra/hist_reber.shtml
Sunday, February 1, 2009
SPECIAL CENTENARY EDITION
A look back to the beginning
Rome Travelogue: Palatine Hill
Fixing my old freq counter: Trials and Tribulations
Empire of the Air:
More great history, but more tech faux pas
"The radio art"
An historical precedent for our GONG
A. Frederick Collins
Understanding Beta Independence
Understanding Feedback and Distortion
SPRAT 137: Minimalist Radio:
The FETer/ET-1: "Haiku from Solder"
Regens: Not for the faint of heart
NEW: THE SolderSmoke STORE: T-shirts, Mugs...!
Shawn N3ZHP new to Knack, wants to build ALL his gear
Steve WB6NTL on hippie origins of "Snort Rosin"
Scott AC0GG recommends new mic, equalizer
Jim AL7RV going QRSS mobile. Can we find him?
George K8VU on kid busted by FCC
Craig KC2LFI helps with SS s sounds
David KB1BED says SolderSmoke driving up Drake 2-B prices
Steve G0FUW "Ten DSB rigs built in cloud of aromatic 60/40"
Brian NF0G HBing at -20F Comet Lulin coming
Tony G4LLW Freq standards, IC extraction, Arc transmitters
Kevin AA7YQ listened to SS while on parachute mission
Graeme ZL2GDN building for DSB and QRSS
Stu N6TTO has new FSK QRSS beacon 10140060
Mark K6HX (has great "Brainwagon" blog) lost SSDRA
Robin AF1RE Heard BITx20s on the air, now is building
Gerry EI8DRB has his 2B
Ray M0DHP has a strange aromatic solder experience...