Earth-Moon-Earth!

I think the really cool thing about this is the “self echo.” Listen carefully when the operator in the video turns it over to the G station. At first I thought they were doubling, or perhaps another station was on frequency. But then I realized that when he releases the push to talk, the first signal he hears is his own signal, bouncing back from the Moon! c is real!

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

DSB Digital Success!

It’s ugly but it gets you there. I finally got the little 30 meter DSB/Direct Conversion transceiver that I built in Rome working on PSK-31 and JT-65. It features a VXO circuit from George Dobbs, an AF amplifier designed by Roger Hayward, and an RF amp chain designed by Peter Parker. It produces about 1 watt of RF. At first I was manually switching the rig from transmit to receive, but this got old real fast, so I built a little VOX circuit — the AF from the sound card does the switching. Last night I fired it up on PSK-31 and stations were calling me (including one fellow in Cuba). Then I went to JT-65 and had a complete QSO with KT1B. Another this morning with K0ASK. It is kind of fun to combine the simple (this rig) with the complex (the computer and these digi modes). I find that I can work both JT65 and PSK 31 while keeping the VXO at 10.139 MHz.

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Homebrew Adventures with JT65

My six dollar DDS board hasn’t arrived yet, so this weekend I worked on the re-build of the 30 meter Direct Conversion/DSB transmitter that I built in Rome (originally for WSPR use). I was hoping to use this rig to make at least a few PSK-31 contacts. But I started seeing these strange looking sigs in the waterfall. I found out they are JT65 (JT for Joe Taylor). So I downloaded the program JT65-HF. I got the receiver going very quickly (it is a 40675 dual gate MOSFET followed by the audio amplifier out of Roger Hayward’s Ugly Weekender RX). The transmitter is just a two diode singly balanced modulator followed by the RF chain from Peter Parker’s Beach 40 Rig. QSOs seem imminent.

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Now That’s A Radio Shack! JH0JDV

I was at the workbench this morning, working on a 30 meter DC/DSB transceiver. I had the Barebones superhet tuned to white noise on 17 meters. Then I heard a strong CQ that sounded like DX. It was Ely, JH0JDV. He was the only signal on the band. We had a very nice contact, no problems at all. I was running my normal 10 watts to a dipole. Afterwards I Googled him. Wow, he has a REAL radio shack! FB Ely!

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

WA0RBR’s Fun-Rig

Last night I called CQ on 20 CW (with my Arduino keying the homebrew transmitter!) and was answered by Mark, WA0RBR. I Googled the call and found that Mark is quite a homebrewer. He wrote a nice series of articles for 73 magazine in the early 80’s. Here they are:

http://mikeyancey.com/73mag/listauthor.php?Author=WA0RBR

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Save 20% on “Hollow-State Design” and “SolderSmoke”!


http://www.lulu.com/shop/grayson-evans/hollow-state-design/paperback/product-20987562.html

http://www.lulu.com/spotlight/soldersmoke

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Chuck Adams’ MUPPET Construction: Manhattan-Ugly-Professional Placement Experimental Technique

From a message from Chuck Adams, K7QO, to the QRP-Tech list:

OK, the rush is on. I figured out what I want to do and now
the race is on to use up over 1,000,000 parts before the
estate sale. :0)

And you know I have to show this to every one, whether any
one uses it or not is up to them. I fell into the following MUPPET
technique through trial and error.

Manhattan Construction: Jim, K8IQY, 1998 winning of Dayton contest
started it.
<http://www.k8iqy.com>
<http://wdv.com/Electronics/Fab/ManhattanConstructionTechniques.pdf>

and then there is the variation on this using the ‘Island cutter’ or
a special
diamond circular shaped drill for making pads. Generates hazard
dust and
I have yet to see some one that can make the same pad every time. I
don’t know of a tutorial online that shows using a drill stop to get
uniformity. IMHO.

Ugly Construction:
<http://www.qrp.pops.net/ugly.asp>
<http://www.arrl.org/files/file/Product%20Notes/chapter_1.pdf>
<http://www.sm0vpo.com/blocks/deadbug_0.htm>
<http://www.alg.myzen.co.uk/radio/qrp/ucw.htm>
and about 16,000,000 other sites with a Google search engine.

Professional Construction:
<http://www.youtube.com/watch?v=xm9vW2I-41g>

And using all of the above I’ll call the ‘MUPPET Construction’ for
Manhattan-Ugly-Professional Placement Experimental Technique
for construction of electronic circuits.

Now, unless you have been hiding in a cave for about 20 years,
all of the above should be familiar to you, except MUPPET. For
lack of a better name, it is the term I will use for collecting all
the techniques together to build something.

OK. Going to the known techniques. What is it that you like and
don’t like? How about expense to get started, other than the parts?

Ugly. Requires a supply of high valued >1Mohm resistors for standoffs.
But is is quick and easy. Some times difficult to debug for some else
that did not build the circuit. What is this gismo here for? …

Manhattan. Nasty super glue and doing the layout. Harbor Freight or
similar punch, some people have difficulty finding. Takes time to place
the pads and let them set.

PCB. Layout time. AND, something no one bothered to mention.
Drilling a lot of holes and getting them all centered is a royal pain.

——————————————–

You still are going to be out some expense for equipment. For MUPPET
you will need a PCB shear/cutter and some cheap items for doing
PCB etching. Don’t give me grief about the muriatic acid. Just
kill it with backing soda when you are done and flush.

Here is an example out of the gate. Just a simple VXO test fixture
to determine why I could not get constant startup on a VXO in a project.

<http://www.k7qo.net/p4110006.jpg>

Then I got excited about not having to drill holes, I can do Manhattan
layouts and as you will see I magically came across a tool that costs
very little and makes things entirely repeatable as many times as you
want.

For the Manhattan projects and my stuff spread around the Internet
like bread crumbs in a fairy tale, I constantly get emails about how
I laid the project out and what software did I use and how I wrote it.
This new technique uses expressPCB for the layout. I just the layout
on the top layer. ExpressPCB, for economical reasons, does not
print out the top layer so that you can easily use the toner transfer
method to make a PCB.

Here is how I get around that limitation. I generate the PCB and
then ‘print’ it out, but not to my Samsung laser printer. I print it to
a ‘PDF’ printer, i.e. the image is sent to a file and converted in the
process to PDF format. I can now manipulate that to ‘reflect it’
about the vertical to get a reverse image, like you do for iron on
shirts, in PDF format and then print that. So now I can do double
sided boards if I ever want to. The reversal is done using a package
called PDFjam for linux and is most likely available for windows.

OK. Here is the most valuable tool for PCB layouts.

<http://www.k7qo.net/p4120009.jpg>

Using the vector board I get exact distances desired between
component legs and when I bend them they will sit FLAT on the
surface of the PCB. And before removing the component from
the board, I cut the leads sticking through the other side to get
the exact same length every time. As it turns out, it is about
0.1″, the same and the standard IC pin spacing and the same
snap points in ExpressPCB. I use 0.1″ SMT pad sizes for the
solder points and 0.2″ spacing in most cases so that I get
the neatest placement possible.

I can use the vector board edge to bend resistors to get
vertical placement on PCBs in kits and here. Each one
will look almost exactly the same. Try it. You’ll like it.

OK, here is a XTAL OSC that I built up in less than an hour,
from start to finish. Yes, you can do it quicker. But I wanted
to able to reproduce the circuits numerous times, if needed,
and now I can easily share them without having to go through
hoops to get the same layout to you or any one else.

<http://www.k7qo.net/p4120007.jpg> Board before populating.
<http://www.k7qo.net/p4120008.jpg> See how neat the transistor sits?
<http://www.k7qo.net/p4120013.jpg> XTAL OSC complete.
<http://www.k7qo.net/p4120014.jpg> Running 11.040MHz crystal.

Side effects. You can do, on the PCB plane on the sides:
Ugly mods and add ons or replacements for larger projects.
Manhattan pad placement for mods, add-ons, etc.

Note. With judicious placement of text, you can document
parts placement for help in building and later showing
someone where you put things and why. Also will help
in debugging something years later.

And just as an experiment. I promise not to cheat.
I will, at 2200UTC, right after posting this email, I will go back
to the lab. I will not eat, nor will I rest until I have done the following
two projects from scratch.
1. Project 001. The HP 8640jr project.
2. Project 004. The G3UUR xtal osc and parameter fixture from QQ.

I want to do this and then show-and-tell the items at tomorrows
flea market/hamfest at DeVry Institute here in PHX AZ and the
AZ QRP luncheon just down the street at the burger place.

FYI and enjoy,

chuck, k7qo (the lab rat #2, since #1 is already taken in NH) 🙂

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Direct Digital Synthesis

I just bought one of these. I hope to hook it up to an Arduino and turn it into a VFO. Or a signal generator. Six bucks!

http://www.amazon.com/dp/B009I7DR7E/ref=pe_175190_21431760_3p_M3T1_ST1_dp_1

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

A simpler DC motor

A few years ago Alan, VK2ZAY, showed Billy and me how to make a very simple DC motor. This one looks even simpler. I’m guessing that the bottom of the coil is making intermittent contact, setting up flux lines that get torqued by the magnets’ field.

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Grayson’s New Book

Our friend Grayson’s book about hollow-state radio is now available. It looks like a great addition to the radio art. Available from Lulu:

http://www.lulu.com/shop/grayson-evans/hollow-state-design/paperback/product-20987562.html

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

King of the Nerds

Are you a super fan of STAR WARS, STAR TREK, GAME OF THRONES, LORD OF THE RINGS, or BATTLESTAR GALACTICA? Are you a GAMER who owns every console and maxes out trophies and achievements? Do you have an outrageous collection of TOYS and/or COMIC BOOKS? Are you passionate about MATHEMATICS, PHYSICS, or BIOLOGY? Do you build ROBOTS or PROGRAMS for fun? Are you obsessed with SUPER HEROES? Are you a D&D or WoW fanatic? Do you love everything SCI-FI? Are you ARDUINO proficient? Do you know at least 100 digits of Pi?Is your IQ at least two standard deviation above the mean? Do you consider yourself a GEEK or a NERD?

Submit a tape and possibly win 100K.

http://nerdking.net/

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

AA1TJ Crosses the Pond using an Electric Razor!

Take a look at Michael’s Razor Rig, made from parts salvaged from his electric razor. I was thinking that perhaps on the receive side a fox-hole receiver made with a rusty Gillette blade would fit in nicely with the shaving theme. Very glad to see the AA1TJ blog getting more active.

http://aa1tj.blogspot.com/2013/04/talking-to-france-via-my-electric-razor.html

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Arduino, K6HX’s code, and an RBN (minimum) speed limit?

Hello Mark: I’ve been using your code. Very nice. Easy to use and modify, even for a digital dunce like me.
I’ve been using an Arduino and your code to key my 20 meter QRP transmitter. I watch the Reverse Beacon Network to see how I’m getting out. I think your code let me discover something about RBN: there may be a lower “speed limit” on the skimmers. I noticed that when I left your code at the default 12 wpm, I was not picked up by the skimmers. When I called CQ the old fashioned way (with my hand!) at 15 wpm I got plenty of spots. This morning I changed the speed setting on your code to 15 wpm and — sure enough — immediately got picked up by an RBN station.
Anyway, thanks for the code and for your Brainwagon blog.
73 Bill

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Yellowstone, Smoke-jumpers, and SolderSmoke on 20 CW

Bill,

It has been a long time since I have written to you. I’m the ex-smokejumper up here in the great winter wonderland known as Montana. I thought I’d drop a quick note to say howdy and fill you in on the crazy string of events that happened this afternoon.

To refresh your memory…. I stopped jumping fire in ‘09, I have continued to be employed with the US Forest Service as a radio technician. Part of my duties is to do annual maintenance on all of the Gallatin National Forest VHF handheld radios. So every winter I update the programming and check the VCOs, RX specs, modulation, and TX power on about 250 handheld radios (luckily the USFS provides me with a handy Aeroflex 3500 service monitor that speeds up this task, but I digress).


Anyhow I had finished programming and tuning a large batch of radios and today I was making my rounds to deliver them to the various offices. My route was from Bozeman (where my shop is) to West Yellowstone (where I used to jump out of) … through the North side of Yellowstone Park to Gardiner), then following the Yellowstone river north up the Paradise Valley (where I grew up as kid) to Livingston (where I live now). I must say it’s an absolutely beautiful drive that took me to 6 of my delivery points. This time of year Yellowstone Park is closed to normal traffic, but official Gov’t use is permitted, so you see very few other vehicles, it’s a pretty neat time of year to be in the Park.

Continuing….I stopped at the smokejumper base to deliver their radios and visited with some of the “bros” for a bit then headed on my way. As I drove off I was thinking of my very last fire jump in Yellowstone and it reminded me that I had written to you back in ’08 about my last jump and listening to “Soldersmoke” while waiting for my ride home. So today as I drove on through the Park I turned on the old Yaesu FT-747 that I installed in my work truck to accompany me on some of these long drives. I did not have the mic or key with me, so I was “voiceless”, but I put the 20m stick on my hustler antenna and turned it on anyway. I enjoy tuning in to some CW while driving and just listening to random QSOs to make use of my drive time by honing my CW skills. Just after I turned on the radio I heard some a W7 station calling CQ and listened for a while in hopes that it might be W7ZOI, I always am listening for the callsigns of the QRP gurus out there, no luck though it was not Wes. I continued listening for quite a while. On the final leg of my trip from Gardiner to Livingston, I was just north of Yankee Jim canyon in Paradise Valley when I heard a very rhythmic CW pattern. It was almost musical sounding, so I tuned it in good, put the narrow filter on and listened. It sounded like the OP was using a Vibroplex bug key, due to the long dash patterns, but the way he keyed it was almost like CW R&B..it was a little tough to copy but fun to listen to none the less. Anyhow as I continued listening, his callsign was KC0MTC in Des Moines, IA and you can guess who he was talking to…none other than yourself, N2CQR!! I couldn’t believe I had just been thinking about “Soldersmoke”, in fact I had even checked the podcast on my iPhone before leaving West Yellowstone to see if a new podcast was posted yet. Then a hour or so later, I hear you live on 14.058500 MHz. What are the chances. I was frantically thinking of a way to jury rig a cable of some sort to plug into my key jack. I was hoping you would make another contact so I could pull over, take a 15min safety break, rig up a key out of headphone cable or something and give you a call by touching the wires together. Unfortunately, you disappeared right after the QSO with KC0MTC. I think you went QRT after that. I tuned all around the CW portion of 20 searching but no luck.

Either which way, I got a big kick out of it and thought it was quite a coincidence. I figured you would appreciate the story. So here is your signal report into Montana …

You were just above the noise this evening, which is quite high S3-4 due to the engine noise in my mobile. You were readable most of the time but dipping into the noise occasionally. I heard you tell him you were QRP but missed the power level you were using. I’d give you an RST of 549, this was about 1730 MDT. Not bad at all for QRP and 1800 miles or so….KC0MTC was booming in a solid 599.


Anyhow 73’s,

Kevin – AA7YQ