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Monday, February 27, 2012
Hubble Ultra Deep Field in 3D
This is about 2 years old, but somehow I missed it. It is really beautiful, and it helps keep things in perspective.
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Winterfest!

We managed to get rid of a bunch of junk, and only bought one item of new junk (a Hallicrafters S-38E receiver). And we got to show our friend (and aspiring homebrewer) John what a real hamfest is all about.
Thanks to the VWS for another great 'fest.
Friday, February 24, 2012
The ZL2BMI DSB Transceiver
Oh man, I've been a fan of this rig for many years. I first read about it in the pages of SPRAT. Today I stumbled across what appears to be an on-line version of the instruction booklet prepared by Eric Sears, ZL2BMI. Lots of lore in there. Lots of soul in this rig. This site has three documents describing the rig. All three are a lot of fun: http://www.mightymessage.com/
Three cheers for Eric Sears! Hip-hip...
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Two Workbenches and a Mini Solder Pot
Hi Bill,
FB...What a great addition to your work bench. Congrats, you will put it to good use! I remember that scope when I worked at the Nuclear Physics Research Department Cyclotron at Indiana University about 30 years ago. It was the top of the line and worked great!! I lucked out by getting a Techtronics 2213 60Mhz dual trace at a Hamfest for a great price a few years back. Luck like that comes to those that wait. I recently gave my work bench a face lift... BTW, the bench doesn't look that nice now...
73,Kent KC9LIF
Dino's bench
Bill -
Ray VK4ZW's "solder pot" idea is a good one....for another version check out Doug Hendrick's tech note at his Hendricks QRP site:
http://www.qrpkits.com/files/MiniSolderPot.pdf
Congrats on the new scope! We have finally moved to our "place in the sun" and I had the opportunity to double the size of my workbench.
73 - Dino KL0S
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Thursday, February 23, 2012
Fat Tubes-day!

I couldn't resist using that title. Stephen from the UK sent me this link to Jeff Duntemann's site about Compactron tubes. Many possibilities here. I think I have a 6T9 in my junk box. These are kind of like tube versions of ICs, but with the advantage of being understandable.
http://www.junkbox.com/electronics/CompactronTubesIndex.shtml
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Tuesday, February 21, 2012
New Oscilloscope!
As you can see below, the 'scope fits perfectly in the center position on the shelf above the bench. I've already put it to work -- here you see it looking at the output from the VFO of the kick panel rig.
A Soldering Tip(!) from Australia
Bill,
I heard you discussing the gadgets that you have in your shack on a recent SolderSmoke podcast particularly the small flame device that you use to remove the enamel from copper wire. I have found the following to be a fantastic way to remove the enamel and tin the wire at the same time. I was alerted to this process by Grant, VK4JAZ, who saw it on the Hendricks QRP Kits site.
Get hold of a basic soldering iron, usually around $10 - $20, and take out the solder tip (you don't need to buy a new iron if you have a spare tip but I find the separate iron allows me more flexibility during construction). Drill a hole in the base of the tip, about 5 - 10 mm, and place the tip point first into the soldering iron. The hole can be filled with solder when the iron is hot and all you do is put the enameled wire into the solder. The heat removes the enamel and the wire is tinned at the same time. The burnt enamel floats to the surface and all you need to do is skim it off before tinning another wire: Simple and neat.
Vy --... ...--,
de Ray VK4ZW
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Sunday, February 19, 2012
Words of Wisdom from Farhan
I read the mail of the BITX20 group. Here is some good advice from Farhan:
I have often seen builders finishing an entire build, then powering it
up to face the frustration of a dead circuit. I suspect that the
trouble is with our kit building mind set. As a kit builder, we assume
that if it has worked well for a few hundred others, there is no
reason for it to not work for us. But the truth is more sobering ...
Of the hundred odd components, any of them could get swapped by
another, or a bad solder, wrong polarity, etc. can all conspire to
thwart your attempts. The bitx manuals are really some of the best
produced in the recent years and yet, even with leonard's videos,
troubleshooting kits is a challenge.
I am proposing a more elaborate, slower but surer approach to building the bitx.
It is as follows: build it one stage at a time, use one stage to test
the next. For instance, one could start with the bfo first. Just a
single transistor with the crystal. Then use an RF probe to check the
rf output. If there is no output, then sort that out before proceeding
to the next stage. With the addition of the buffer amp, the output
should go up. Then one could proceed to the audio amp. Injecting audio
from your mp3 player or computer could check that it works. Next,
replace the audio source with the mic amp, this tests the mic amp.
Now, if you add the two diode modulator, you should be able to receive
the dsb at 10 MHz on your HF transceiver.
This approach tests each stage individually and in isolation before
proceeding to the next. It also provides wholesome education to the
builder. In software industry, it is called a 'test driven
development' method of developing software.
In the end, this approach is no slower than the current approach,
except that surprises are not kept for the last.
I am sure that some of us can come out with a sequence of stages to
build where each stage is tested using the previous stage.
As much as bitx is about building it cheap, it is also about learning
your radio from inside. Bitx is also education on the cheap, don't
give up that opportunity.
- farhan VU2ESE
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
I have often seen builders finishing an entire build, then powering it
up to face the frustration of a dead circuit. I suspect that the
trouble is with our kit building mind set. As a kit builder, we assume
that if it has worked well for a few hundred others, there is no
reason for it to not work for us. But the truth is more sobering ...
Of the hundred odd components, any of them could get swapped by
another, or a bad solder, wrong polarity, etc. can all conspire to
thwart your attempts. The bitx manuals are really some of the best
produced in the recent years and yet, even with leonard's videos,
troubleshooting kits is a challenge.
I am proposing a more elaborate, slower but surer approach to building the bitx.
It is as follows: build it one stage at a time, use one stage to test
the next. For instance, one could start with the bfo first. Just a
single transistor with the crystal. Then use an RF probe to check the
rf output. If there is no output, then sort that out before proceeding
to the next stage. With the addition of the buffer amp, the output
should go up. Then one could proceed to the audio amp. Injecting audio
from your mp3 player or computer could check that it works. Next,
replace the audio source with the mic amp, this tests the mic amp.
Now, if you add the two diode modulator, you should be able to receive
the dsb at 10 MHz on your HF transceiver.
This approach tests each stage individually and in isolation before
proceeding to the next. It also provides wholesome education to the
builder. In software industry, it is called a 'test driven
development' method of developing software.
In the end, this approach is no slower than the current approach,
except that surprises are not kept for the last.
I am sure that some of us can come out with a sequence of stages to
build where each stage is tested using the previous stage.
As much as bitx is about building it cheap, it is also about learning
your radio from inside. Bitx is also education on the cheap, don't
give up that opportunity.
- farhan VU2ESE
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Kick Panel Rig: EXPOSED!
I thought I was having some trouble with RF getting into the mic amp. The audio out from the mic amp looks a bit distored when I have the oscillator and PA circuits fired up. I worked on it for a while, beefing up the decoupling on the 12 volt lines, but that didn't change things. I've decided not to worry about it, because the output signal from the final looks clean, and the signal sounds good on my trusty Drake 2-B. It may have been a test gear problem -- the 'scope probe may have been picking up some RF and may have been uglying up the AF wave form.
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Wednesday, February 15, 2012
Kickin' the Kick Panel to 40?
Craig and OM KWJ suggested 10 meters. I hear you, but I'm looking for a rig that I can use for pre-dawn rag chews, and at that hour 10 is often a white noise generator.
Bruce wants me to put it on 475 KILO hertz. I dunno about that one Bruce -- sounds kind of lonely!
As I thought this over, I remembered a comment from the true guru of DSB: Peter, VK3YE. In one of his inspiring videos, he mentioned that 40 meters is his favorite band for DSB rigs. It is 0545 local and I am hearing a lot of activity on 40. It all sounds very friendly. Some DX coming through... I could make a stable VFO for 40. Then I add a little DC receiver and I'm in business. So I'm leaning towards 40 meters at this point.
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Tuesday, February 14, 2012
Back to the "Kick Panel" DSB Rig
The oscillator is running as it should and the RF amplifier chain (my design) is amplifying (and not oscillating!). The balanced modulator is doing its balancing act quite nicely. The only problem seems to be with the the little op-amp that have in there for the AF -- it seems to be distorting the audio quite a bit. That shouldn't be hard to fix.
There is room in the box for a simple Direct Conversion receiver, so this box will become a DSB/DC transceiver.
But here is my problem: I find myself unenthusiastic about working on a rig for 75 or 80 meters. On the one hand those frequencies are good for me -- I'm an early riser and I need a rig that I can use in the hours before sunrise. But 75/80 always seems to be an unfriendly place -- lots of frequencies that seem to be "claimed" by groups who don' t seem interested in meeting newcomers, not a lot of people calling CQ...
I can put this rig on another HF band. 40 seems nice, but I have plenty of old boatanchor stuff that covers 40. I don't need another 17 meter rig. I already have a homebrew 20 meter DSB rig. How about 12 meters? Or 10? I know they are both dead in the early morning, but better times are coming, right? What do you guys think? To what band should I kick the kick panel rig?
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
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