SolderSmoke Podcast #172 is available http://soldersmoke.com/soldersmoke172.mp3 16 February 2015 Bench Reports: Pete under the gun to finish SSB transceiver project. NEW VIDEO: http://youtu.be/hbLXW0sHTFo Bill fixes his BITX 2040 Oscillator (Bandsweep!) Next: LP filter for 120 watt amp. Bill's 13 dollar Chinese freq counter (Blue! With anti-wobble tape!) Bill's next rig: Chipped to the Max, DDS, SBL-1s, plug in filters! Radio Shack going under and JAN no longer making crystals. Mighty Mite Project: Let's get them DONE! An easy way to get Q or ESR measurements on crystals? SI5351 as a crystal substitute. DuWayne's Scalar Network Analyzer lights up the internet! The Portable SDR rig -- Pete almost goes to the dumpster! Report from the cutting edge: Pete's new Elecraft KX3. MAILBAG: Meeting W7ZOI and WA7MLH at a hamfest. Instant Messaging with Farhan
Oh man, we've all been there in one form or another. The struggle, the frustration, then, THE TRIUMPH! I love when his mother drops the plate. Thanks to John KC0BMF
It has been a while since I visited the Amateur Logic TV site. When I looked in last week I found George and Tommy building a spark transmitter. Pretty cool! The sparks begin to fly at about about the 23 minute point in this video. Very interesting. Way to go guys! SPARK FOREVER! (You will see that emblazoned on the QSL cards of REAL old timers. They were railing against those newfangled Continuous Waves. There is a lesson in there for me... )
Lots of tribal knowledge here! That's the direct conversion receiver that forms phase 1 of Pete and Ben's "Let's Build Something" project. Arduinos! Si5351s! AD9850s! And it will morph into an SSB transceiver. Check it out: http://www.jessystems.com/LBS_Detail.html
Holy cow! Look at that rig. The whole HF spectrum. AM, CW, SSB, Digital Modes, Waterfall display, GPS. It may even have a Vector Network Analyzer! (Deep breaths Pete Juliano, deep breaths!) Michael KE7HIA is trying to get this project going via a Kickstarter campaign. He needs to get to $60,000 He currently has about $47,000 pledged. There are only 42 hours to go: https://www.kickstarter.com/projects/1703258614/psdr-pocket-hf-sdr-transceiver-with-vna-and-gps Wow, this rig would have been great for my Double A DR DX-pedition!
Features:
Coverage from 0 to 35MHz
Waterfall display that lets you see radio signals
Receives AM, USB (Upper Side Band), LSB (Lower Side Band), and Morse code (CW)
Modulates USB and LSB signals
Variable bandpass filter
Hardware:
Powerful ARM processor
Color LCD display
Dual DDS frequency Synthesizers
Quadrature Sampling Detector & Exciter
Digitally controllable instrumentation amplifiers
Morse Code key (the "Giblet" on the bottom right corner of the enclosure)
Magnitude & Phase measurement chip (for VNA and antenna analysis functions) with Impedance Bridge
Dual SMA connectors, smartphone style earphone/microphone connector, and USB port
GPS
Built in Microphone and Speaker
Internal Lithium Polymer battery with charger and high efficiency switching regulator
MicroSD slot
Pads for grabbing raw I/Q signals, both in and out.
Things it will be able to do with your help:
I designed the hardware to be capable of the following, but I can't write all the software myself. Please note that I can't guarantee when or if these functions will be added, or that they will work as desired.
Work as a full Vector Network Analyzer (VNA)
Work as a spectrum analyzer
Cover more modes, including digital modes and image modes
Work as an emergency location beacon
Antenna Analyzer
Frequency Synthesizer
Media player
E Reader / Picture viewer
Have improved audio
GPS Mapping navigation device
High end ARM development board
USB control of any features, including the possibility to operate the PSDR remotely. The USB port supports USB On-the-Go, making it possible to connect keyboards or other devices. Firmware updates will also be possible over USB.
The K1N DX-pedition is currently on Navassa Island (between Jamaica and Haiti). This made me think of one of my earliest ham radio memories: The 73 Magazine article on a 1972 operation on that island. Here is a short video on that trip. It is kind of wacky and fun.
Excellent Lucien! Thanks for sending this. I know what you mean about a project that doesn't work. It is rewarding and educational to figure out where you went wrong. I knew a guy who would ask, at a hamfest, "Does this rig work?" If the the seller admitted that it didn't, he'd reply, "Good, I pay extra for that!" He liked the challenge of fixing it. Of course, there are limits to this, and sometimes these challenges will make you wish you had taken up stamp collecting.
Hi Bill and Pete,
For me too, it's a happy day - I got the Mighty Mite working! Thank you so much for the inspiration to get into homebrewing...
I'm just licensed for a year now and this was my very first project (except for 2 basic kits that I build) and it really was a great learning experience. The best part: Since it didn't work out "plug'n play", I had to debug the thing and actually start thinking - so I put 2 caps in parallel instead of the wrong one I had used (I found them in a little box some guys at a hamfest gave me for free - never thought I would ever use something from it...). And I had to use the voltmeter to look for a short circuit. Basic stuff, but for me, this was a breakthrough!
Here are some more things I learned during this first project (don't laugh):
Where the heck do I plug stuff that's supposed to go to "ground" in? Now I know: usually to the negative pole!
When 2 lines cross in a schematic, that doesn't mean there's a connection!
How do these ready-made breadboards actually work? Had to try out...
It's important to think about the actual layout beforehand!
When debugging, trial and error doesn't help.
There's yet another crazy foreign unit called "gauge"! (I used smaller magnet wire than recommended, it still seems to work...)
9V-blocks get VERY hot when shorted for a minute or so!
Attached is an image of my ugly prototype, now I want to give it a better "home"... And here is a little video, demonstrating that it works, inspired by IZ1KSW:
This is my very first homebrew project guys and I'm so excited! I started from scratch... and when I say from scratch, I mean that I didn't even have one of the 7 components required, no PCB boards, no junkbox, nothing... just the soldering iron and the will to "build something".
Thanks to Pete suggestions I managed to put some components together and now I have a (small) junkbox (I'm very proud of it) and thanks to soldersmoke I entered the ranks of the homebrewers.
I send you also a couple of pictures, I used Manhattan style and I found it very useful to understand the circuit. It's far from being a clean and neat building but it's a first step.
These little frequency counters from China have a lot of potential. And they add a dash of digital color to an otherwise bland analog hamshack. I got mine on e-bay. My BITX17 has now been "accessorized" with 1) A rotatable Moxon antenna (big improvment!) 2) A 120 watt Communications Concepts Linear amplifier (another big improvement) and 3) This digital frequency readout. What next?
DuWayne (KV4QB) has done something very cool here. He's taken an Arduino Nano, a cheap AD9850 DDS board, a small screen, and a couple of log detectors, and he has built IN AN ALTOIDS TIN a scalar network analyzer that lets you see the bandpass of a filter. (We posted an earlier version of this here: http://soldersmoke.blogspot.com/2015/01/duwaynes-ad9850-arduino-tft-swr-scanner.html ) Wow. I've been doing this by hand, changing the input freq at 100Hz increments, measuring the output, putting the results into a spread sheet, converting to log (db), creating a graph... DuWayne makes it a lot easier. DuWayne is being encouraged to write up the results, possibly for QRP Quarterly.
Hi Guys Started playing around with the SWR scanner that I had been working on. Waned to see how hard it would be to make a very simple scalar network analyzer out of what I had. Really wanted something small to use for checking bandpass other filters. Hoped to get about 30 db. of range ,which should be enough for most filters. I have a couple of 8307 log detectors, but was afraid that it would be a pain getting it working and shielded in an Altoids tin along with the rest of the circuitry. Went with something even easier than the resistive SWR bridge I already had. Replaced the bridge with two basic diode RF probes, and changed the amplifiers so I could adjust the gain. I use one to measure the direct output of the 9850 DDS module, and the other for the output of the device under test. Kept the same control function as in the SWR scanner. A short push on the encoder button starts a sweep of the selected band. Holding it down for over a second cycles through the bands. Once a scan is done you can use the encoder to scroll through the sweep. I display the frequency and iDUT value in db relative to the output of the DDS module. The USB connector is available and different start and stop frequencies can be entered if needed when working with IF stages.
Well it worked much better than I had expected. After a simple adjustment of the amp gains with the output looped directly to the input, I was getting nearly 50 db with the loopback removed. Just using some standard value resistors, in a pi attenuator I got a very nice looking sweep that was within a couple db of the 40 db i had built it for. Since I only used standard value resistors, I though this was good enough.
Then I used ELSIE to design a 14mhz lowpass filter, again used standard values for L and C that I had on hand . Really happy with the results I got.
Finally I grabbed 3 crystals out of a bag without checking frequency or other parameters, I threw together a basic crystal filter. Used the USB interface to set the sweep range, I was really really really pleased with the results I was able to obtain.
The software still needs a little tweaking and a couple of additional functions I want to add, but I think this will be a very nice tool. Plan on giving it a try when I build Pete's Lets Build Something transceiver. Amazing what you can stick in Altoids tins, even if you have to stack two so you can include a battery pack .
Attaching some pictures of the progress so far. As you can see that with what I used to build the test fixtures, I am amazed that they even worked at all. 73 DuWayne
