Just go to http://soldersmoke.com. On that archive page, just click on the blue hyperlinks and your audio player should play that episode.
http://soldersmoke.com
The French "repairability index" is an interesting concept. I wonder how modern ham radio "radios" would score. I think our homebrew rigs would max out the index.
Pete has commented on manufacturing processes that do (or don't) factor in access for repair.
One of the recent horror stories we've heard is about a certain manufacturer of mobile phones. It seems that they have designed the phones so that if you dare to replace a broken screen, the new screen won't work unless you de-solder the associated chip, then re-solder in the SAME CHIP.
In his recent interview with Eric Guth, Courtney Duncan N5BF told us that the communication between the Ingenuity helicopter on Mars and the Perseverance rover is being handled by off-the-shelf Zigbee 900 MHz transceivers.
I did some Googling and found some more details on this:
----------------------------
"Once separated from the host spacecraft (lander or rover), the Mars Helicopter can only communicate to or becommanded from Earth via radio link. This link is implemented using a COTS 802:15:4 (Zig-Bee) standard 900 MHz chipset, SiFlex 02, originally manufactured by LS Research. Two identical SiFlex parts are used, one of which is an integral part of a base station mounted on the host spacecraft, the other being included in the helicopter electronics.
These radios are mounted on identical, custom PC boards which provide mechanical support, power, heat distribution,and other necessary infrastructure. The boards on each side of the link are connected to their respective custom antennas.
The helicopter antenna is a loaded quarter wave monopole positioned near the center of the solar panel (which also serves as ground plane) at the top of the entire helicopter assembly and is fed through a miniature coaxial cable routed through the mast to the electronics below. The radio is configured and exchanges data with the helicopter and base station system computers via UART.
One challenge in using off-the-shelf assemblies for electronics systems to be used on Mars is the low temperatures expected on the surface. At night, the antenna and cable assemblies will see temperatures as low as -140 C. Electronics assemblies on both base station and helicopter will be kept “warm” (not below -15 C) by heaters as required. Another challenge is antenna placement and accommodation on the larger host spacecraft. Each radio emits approximately 0.75 W power at 900 MHz with the board consuming up to 3 W supply power when transmitting and approximately 0.15 W while receiving. The link is designed to relay data at over-the-air rates of 20 kbps or 250 kbps over distances of up to 1000 m.
A one-way data transmission mode is used to recover data from the helicopter in real time during its brief sorties.When landed, a secure two-way mode is used. Due to protocol overhead and channel management, a maximum return throughput in flight of 200 kbps is expected while two-way throughputs as low as 10 kbps are supported if required by marginal, landed circumstances."
Yesterday I went through my novice logs from 1973-1974. I was in Congers, NY and my call was WN2QHL. Please take a look at the callsigns from my log and let me know if we had a contact. I will then let you have more details from my log.
There are a number of good ideas in this video. We've known for a long time that many expensive mics are really simple, cheap mic capsules in fancy packaging. This video takes a $12 mic capsule (which looks a bit like the ones we are using for the podcast), adds come amplification, a USB interface, and some really cool looking bronze packaging to come up with a very nice microphone.
I liked his use of solder wick as a shield for the DIY mic cable. Who knew the wick was hollow! I also like the cooking torch for use in soldering the brass. I need one of those. The little Murata DC voltage booster with positive and negative output seems useful.
It seems that anyone working on this kind of project quickly gets pulled into the use of "audio speak." Late in the video Matt says his mic has nice low-end "presence." A quick look at the comments section shows one person saying that one or the other of the mics sounds a bit "moist."
There are many other similarly interesting projects on Matt's YouTube channel:
This morning Eric Guth has a really interesting interview on his QSO Today podcast.
Courtney Duncan N5BF had a full career at JPL and is the current president of the San Bernardino Microwave Society. There is a lot of interesting stuff in this interview, much of it about space exploration. Courtney tells us about how experience with re-purposing radio gear came in handy at JPL. For example, the helicopter that they have been flying on Mars has a very cheap and light off-the-shelf Zigbee transceiver. He also talks about the origins of the Cube Sats.
Here is Eric's page on this interview, with useful show notes:
I really liked Nick M0NTV's approach to making a crystal filter (see video above). He really simplifies a process that desperately needs simplification. I remember when I was building my first superhet receiver, I came across Doug DeMaw's schematic for a crystal tester that would allow me to properly build the filter. But the piece of test gear was far more complicated than the receiver I was building. I never built Doug's device.
Nick's technique is simpler even than the G3UUR method that many of us have been using for years. Nick dispenses -- wisely I think -- with the need to calculate motional parameters, Q, and equivalent series resistance. This also eliminates the need to fidget around with the design software such as Dishal or AADE.
Nick uses the Cohn topology (good choice) and uses kind of an "informed cut-and-try" technique to come up with the capacitor values.
Filter impedance is determined with series trimmer resistors and the NanoVNA to watch the resulting passband. Nick says this is a Charlie Morris ZL2CTM suggestion. It obviously works very well -- the ripple that would result from impedance mismatch is eliminated.
Nick's determination of the best turns ratio for the impedance matching transformers is brilliant.
Nick apologizes for what he says is a long video. But it is only 30 minutes or so long, and if you are going to build your own superhet or SSB filter rig, it is well worth watching.
Three cheers for Nick and for Charlie! Thanks guys!
A few days ago I put up a blog post about using a noise generator (in my case my cheap FeelTech sig generator) and my TinySA spectrum analyzer to look at the passband of a crystal filter. I was using the 9 MHz filter used by Dean KK4DAS and the Vienna Wireless Makers Group. The idea is simple: insert broadband noise into the input. The filter should pass more of the noise that falls within its passband. The TinySA should let you see this. At first, I was pleased that I could clearly see the passband. I thought I had succeeded. See above.
But I was bothered by something. Look at that bump in the passband. It should be close to flat across the top.
I decided to take a look at the same filter with my NanoVNA. Here I was not using a noise generator. The NanoVNA sweeps the filter using and looks at output in the Log-Mag mode. Here is what it looked like (below):
That was much better. But why the difference? Tony Fishpool G4WIF suggested that my noise source might not be putting out noise at the same level on all frequencies. I took at look at the noise output of the FeelTech sig gen in the range of the filter passband (with some above and below frequencies for reference) and I found that the flatness of this noise depended a lot on what frequency I had the sig gen set to. I tuned it around a bit until I found a setting that produced a flat noise output in the desired frequency range. Then I went back and swept the filter with the noise and the TinySA again. Here is what it looked like with the "flat" noise:
Better, I think. Closer to the passband displayed by the NanoVNA.
Tony points out that these Chinese sig gens don't really put out random noise -- they give us predictable noise. Dean said "Predictable Noise" would be a good name for a rock group. I said they could open for my favorite: "The Ceramic Spurs."
The presentation starts at about the 4 minute point.
I think if I were only allowed to watch one YouTube video in the next year, I'd make it this one.
In this amazing RSGB video, Ashhar Farhan VU2ESE takes us back to his earliest days as a radio amateur. He tells us about his very early desire to build radios, his early projects, and his personal evolution as a designer and builder, from a simple DC receiver, to the BITX, the Minima, the uBITX and now the hybrid HDR/SDR sBITX.
There is a lot of homebrew wisdom and tribal knowledge in this video. And we learn so many hitherto unknown details about the rigs that have become so important to us:
-- Farhan had the EMRFD book with him on the famous flight from Sweden to India during which the BITX was designed.
-- We learn about the origins of the BITX oscillator circuits, and that the VFO and BFO are essentially the same.
-- I was really pleased that Farhan included a picture of my HB BITX17 rig in his presentation.
-- Farhan discusses the difficulties he faced in obtaining needed parts in India.
-- We actually see the nylon washers that Farhan used in the original BITX.
-- Farhan discusses his early system for measuring coil inductance.
-- In addition the huge contribution of EMRFD, Farhan talks about how he was helped by Pat Hawker G3VA's writing, and the ARRL's SSB Handbook.
-- Farhkan talks about his Tex 465 'scope and his building of a Spectrum Analyzer.
-- We see his evolution to dual conversion. We see the conceptual birth of the Minima and the birth (thanks Wes!) of the TIA amps. I didn't know about the HF-1. Then Farhan designed the uBITX and now the sBITX.
-- Farhan talks about his practice of taking the pictures of new rigs with the new rig sitting atop the book that was most important in its design and construction. FB.
-- I was really blown away by Farhan's presentation of how the uBITX advertisement was inspired by and in many ways based on the Heathkit ad for an HW-101. Amazing.
-- I learned a lot from Farhan's discussion of SDR theory. I pledge to spend more time with this. I really like Farhan's hybrid HDR/SDR approach.
-- But I have a question: Farhan seems to say that we'd need a big expensive GOOGL computer to do the direct sampling HF SDR. But doesn't the little RTL-SDR do just that? Without a GOOGL?
-- Great to see Wes's AFTIA being used in the sBITX.
-- Really cool that Farhan has his mind on VHF transverters when designing the sBITX. I liked use of the TCXO module to free up one of the Si5351 clock outputs. FB. And great to include an idea from Hans in this rig.
Thanks very much to Farhan (who stayed up until 3 am to do this!) and to the RSGB for hosting.
Only 85,000 Euros (that's the opening bid). But hey, it comes with the receiver pictured on the right. I guess that's so you can listen to the beeps.
Here's the description:
---------------
Laboratory Test Model of "Sputnik 1 EMC/EMI", 1957 1:1 scale test model of the satellite "Sputnik-1", serial no. "0K6-1/004/1957", with built-in transmitter (including modern 12-volt power supply), polished stainless-steel sphere, consisting of two threaded hemispheres of approx. 23 in. diameter with two pairs of antennae of 95 in. and 105 in. at an angle of 35 degrees to the axis, on stand with O-ring, stand approx. 59 in. high, stand and model together approx. 79 in. high, accompanied by a Tesla Maj 620A radio receiver, manufactured in Prague c. 1956, restored working condition, including replacement of the silver-zinc battery with a modern alternative and a new metal casing for the electronic transmitter. Note: Built at the Experimental Design Bureau-1 (OK?-1/OKB-1) factory, also known as S.P. Korolev Rocket and Space Corporation Energia, Koroljow, Soviet Union, in 1957, shortly before the launch of Sputnik-1. - An impressive artefact from the dawn of the space age, of which few models are known. - Provenance: From the collection of Dr. Frank Malina, USA/CSSR.
Start Price: EUR 85.000
---------------------------
I'm a bit suspicious of the "modern 12-volt power supply," the "modern alternative" battery and the "new metal casing for the electronic transmitter."
Here's my suggestion: Musk or Bezos or Branson should buy this thing, fix it up a bit, and put it back in orbit. So we can listen to it again. I know a version of this was done back in 1997. But I think we should do it again, this time with the actual test model.
Here are the earlier SolderSmoke blog posts about Sputnik and Sputnik-related projects:
Steve Silverman sent the auction posting to me. Thanks Steve.
It just so happens that earlier in the week I was out at the Air and Space Museum facility near Dulles Airport, where I saw this flight backup of the Vanguard satellite:
I've been meaning to try this for a long time. Years ago Tony Fishpool and Graham Firth wrote about using a noise generator and a spectrum analyzer to sweep the bandpass of a filter. The idea here is to send very broadband noise into a filter, and then use a spectrum analyzer to see which frequencies make it through.
I thought about building a noise generator like the one in Tony and Graham's book, but then it occurred to me that probably had one sitting on my bench. Sure enough, a look at the manual for my cheap FeelTech function generator revealed that PRESETS 3 and 8 are noise generators. I quickly pulled out a 9 MHz filter that Dean KK4DAS had given me, put the noise into one end and the TinySA on the other end. Bob was quickly my uncle. See above.
More recently Tony G4WIF built a comb generator as a noise source:
Because our podcast and blog is called SolderSmoke, I felt compelled to post about this video in which a fellow does some pretty interesting research into how solder smoke actually moves. We don't often see this much concern about the behavior of our beloved smoke.
"SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
http://www.amazon.com/dp/B004V9FIVW
Bill's OTHER Book (Warning: Not About Radio)
Click on the image to learn more
Where are the readers of SolderSmoke Daily News?
Pete Juliano N6QW
SolderSmoke Co-Host and Master Homebrewer
Dean Souleles KK4DAS
With beret and with a Michigan Mighty Mite in hand
The Eternal Question: Which Radio Should I Pack?
-
It’s a question as old as time itself: “What radio should I take on
vacation?” This month, we’re heading out for a short vacation, and while I
think I’ve a...
Bob’s 1968 Radio Tirana QSL Card
-
Many thanks to SWLing Post contributor Bob Colegrove, who writes: Kudos to
Don Moore for his excellently crafted article on Albanian radio. […]Perhaps
some...
Linux Mint, QRP, & C / C++ Compilers
-
Greetings:
On the bench I'm studying PLL techniques using a sample & hold detector +
VHF circuitry. Currently, I've got nothing to post RF-wise. Another...
December 11, 2024. We take things for granted.
-
We often take things for granted! You know, you snap on your homebrew rig
or appliance box, and it comes alive. Or that if you want a fresh salad,
there is...
MeSQUAREs alternative - 1/32" board
-
MeSQUAREs are excellent. I've purchased them from QRPme in the past and
used them with great success. I get through them very quickly and find it a
bit unf...
HRWB 224 - 2024 Holiday Shopping Show
-
In this episode we give you the buyer's guide to holiday cheer. The team
put their heads together to come up with many suggestions for the
workbench, ha...
The November - December 2024 SARC Communicator
-
*Another BIG issue*
The final issue of the year. The November-December Communicator, digital
periodical of Surrey Amateur Radio Communications is now avail...
Hollow-State Design, 3rd Edition
-
Hollow-State Design, 3rd Edition is available from: Lulu Press:
tinyurl.com/hollowstatedesign3 eBay: search for “hollow-state design”
Electric Radio bookst...
I Finally Bought My Dream Airplane
-
Aviation has been a love of mine since I was a very little person. Living
in Nevada, seeing posters and ads for the Reno Air Races, specifically the
Texa...
2000 47pF Caps ...
-
An unexpectged package arrive in the mail today. Did you ever wonder what
2000 47pF NP0 capacitors look like? Thanks to John, AB2XT I will never run ...
New QRP Cluster From OM0ET and OM6APN
-
By DX EXPLORER
DX EXPLORER
Paul OM0ET and Peter OM6APN recently launched a new cluster dedicated to
QRP operations. Have a look and I hope you will enjoy...
Daylight Again – An all Analog Radio
-
What’s all this? In 10 seconds, A high performance, 7MHz, 5 watt SSB rig
Draws just 24 mA of current 90 dB dynamic range, 80 dB close-in dynamic
range 3D ...
Digi-chirp! Digital synthesis of ‘nostalgic’ CW
-
The bottom ends of 80, 40 and 20m are not what they used to be. For
starters, the busiest part is the digital segment where computers talk to
computers – l...
SMA Torque Wrench for the NanoVNA (uncalibrated)
-
I have been using SMA connectors on most of my projects, and have
occasionaly gotten a slightly different reading than I had expected. Using
the NanoVNA, ...
40m SSB Tramping Rig
-
Please see my YouTube channel for details of the build.
http://www.youtube.com/c/CharlieMorrisZL2CTM
*2N3904 Antenna Amplifier (initial)*
Voltage gain is ...
Modifications to the Dayton/FDIM-2019 Antuino
-
The Dayton Antuino has sub-optimal performance. This is a short note on
improving it to an 80 db range of measurements. The trouble with Antuino
2.0 (the o...
Raduino as NBFM TX
-
Here is a neat, 30 minute hack for your Raduino to turn the Si5351 into a
pretty stable, solid NBFM transmitter. The hack is to add a varactor diode
in ...
QRP Labs shop!
-
[image: Shop]
All QRP Labs kits may be ordered online securely at the shop, with PayPal
payment.
*Click here to visit the shop!*
*Click!*
*Shop! Order...
Posts
