Just go to http://soldersmoke.com. On that archive page, just click on the blue hyperlinks and your audio player should play that episode.
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Hi Bill, Pete "The Crossword Guy" K4PHS here again. In the New York Times Crossword for Tuesday June 21, 2016 the clue for 52 across is: "Enough, Enrico!" And the answer is: "Basta!" 72, Pete, K4PHS And from October 5, 2015 Hi Bill,
The clue for #7 across in todays New York Times Monday Mini Crossword puzzle is:
I was quite pleased with the valuable items obtained at the Manassas Virginia Hamfest this morning. Armand WA1UQO and I once again combined forces, offering each other advice and counsel (NO! Forget it!) as we went through the flea market. Above you can see what I got: TOP ROW: 1) A bunch of boxes. Nice aluminum boxes and two really good chassis. I may now have to build something with thermatrons. Armand gave me a really nice Ten-Tec box. Thanks Armand! MIDDLE ROW 2) Ten much needed coax patch cords. I promise to check the connections before using them. Really. I mean it this time. 3) A nice circular coax switch. 4) Two large hemostats. I told the woman I needed them for some surgery that I'd be performing later in the day. She was not amused. 5) A homebrew SWR Monimatch box. Amazing. Dennis Klipa and I have been talking about these, so I bought this homebrew version. 6) Nice Jackson Brothers reduction drive with tuning indicator. 7) Really nice variable cap. 8) Three crystals: two for 3.579 MHz CBLA work, the other for 40 meter phone. 9) Forehead "coalminer" lamp 10) Some PC boards. BOTTOM ROW 11) LARGE box of 455 kc IF transformers
As we were making the rounds we ran into Charles AI4OT. On the tailgate of his truck Charles had a BITX20 in operation! You can see it in the picture. Great to see you Charles and FB on the BITX.
Jan is at it again, this time building a Dutch version of Lew McCoy's Mate for the Mighty Midget. Look at front panel! But wait, there is more!
Here is a side view of the chassis. Wow. What, you may ask, is that round thing?
Holy cow! Homebrew Vernier reduction drive made from the cap of a sewer pipe. And a homebrew dial cord arrangement. Jan is clearly breaking new ground in ham radio homebrew re-purposing.
Jan writes:
Bill:
Here a little update on the MMrx.
Got almost all the parts, except for the Miller 4411 300 uH coils, for which I am attempting to make my own.
While I was looking for some pictures of this coil, if it was shielded or not (found a vintage online Miller catalogue J ),
I stumbled across this article, the W2MQ “Hamster”
There is no mention of the MMrx, but the text is very in line with the latter. Nice read.
I found this in my junk box. I've put it in my old Mate for the Mighty Midget receiver, in the place of the Toyo CM455 crystal-mechanical filter (which I found to have excessive insertion loss). I think its very cool how they squeezed two variable caps into that little can. Designed in 1956. Works great. Note the promised passband: 4.7 kc at 6 db down. Not bad for an LC device. Here is the spec sheet:
Our ace correspondent Bob Crane W8SX caught up with Eric Schwartz WA6HHQ of Elecraft at the FDIM event n Dayton last month. Here is Bob's interview with Eric: http://soldersmoke.com/WA6HHQFDIM.mp3
Pete and I were very pleased to see that Elecraft made use of our beloved Si5351 chip in their amazing new KX2 rig.Check it out:
You can click on the diagram or see it directly on page 62 of the manual at this site:
Steve Silverman sent me this link. This web site has been getting a lot of attention from the solder melting community. And justifiably so. Behold (above) the first transmitter built by Robert Glaser, now N3IC, circa May 1969. The chassis and front panel were made from flimsy printing press sheet metal. Note the key (as in lock and key) switch that the OM put on the front panel -- he took his responsibilities under FCC regs quite seriously. My favorite part of this rig's story is that when he got it done, he didn't have the two 6146s for the final. So he just took a capacitor and used it to connect the driver tube to the output network. Brilliant! With that arrangement he made his first contact. No wonder he labeled it "Excitatation!" It was clearly more exciting than your standard excitation.
Those TV power transformers look very familiar. I was using similar devices to build a power supply for an HW-32A a few years afterDr. Glaser built this rig. It's a wonder we survived.
FB. Check out his site. It is a wonderful catalog of all the stuff this very prolific builder has made over the years:
This amazing picture was taken last night at the Bharati Indian Base Station in the Larsemann Hills of Antarctica. The researchers there report that the aurora was so bright that it cast shadows.
Yesterday I was having a nice 40 meter SSB contact with N3TDE. Rich is 179 miles away, in Pennsylvania. At 1650 UTC, his signal very suddenly dropped into the noise.
The purple lines along the bottom of the chart below probably explains both the aurora and the abrupt end of my 40 meter contact.
Jaydip VU3JOJ came up with a really inventive way to box up his new BITX transceiver. Nicely done. I especially like the way he put the speaker in the space intended for the fan. Very nice.
This appears to be one of the new BITX 40 meter "modules" described in yesterday's blog post. FB! How fortunate the new board fits in the power supply boxes. That's very lucky.
You know, I had an old computer power supply in my hand just yesterday. I almost threw it out. Obviously that would have been a mistake.
Today was a BITX day. Using my BITX DIGI-TIA on 40 I had a long QSO with Rich N3TDE. Rich has a BIT20 built from a Hendricks kit acquired at Dayton. He takes it with him on the Appalachian Trail.
Wow, that board is a thing of beauty. And the story behind it is even more beautiful. Our friend Farhan took his famous BITX circuit, shifted it to 40 meters, and put the whole thing on one small board. It is now a module, but a module that makes up an entire SSB transceiver. The idea is that this module can provide a base for expansion and experimentation. You can add a digital display. Or a (gasp!) digital VFO. Or an RF amplifier. Or more bands. Or all of the above. It is a very cool idea.
Here is the most beautiful part: In an effort to help people who need help, Farhan has arranged for a collective of women to assemble the boards in their homes. They needed work, and Farhan gave it to them on good terms. Bravo Farhan!
In keeping with the earliest purpose of the BITX rigs (simple transceiver for Indian radio amateurs) this board is currently only available in India.
Ryuu's blogs are here : http://ja2nkd.blog.so-net.ne.jp/ and here: http://ja2nkd.blogspot.jp/ They are in Japanese. Google Chrome does a poor job at translating them, but you can get the gist. In any case the pictures are great and the schematics are understandable by all of us. Thanks Ryuu!
Grayson Evans was at Dayton. Scheduling problems prevented him from being interviewed by ace correspondent Bob Crane, but Grayson was kind enough to e-mail us the essence of his presentation. And it is really wonderful. He brings the advantages of the Manhattan construction technique (fast prototyping, all components on the same side of the board, easy modification) to the world of tubes (aka valves or, as Grayson prefers, thermatrons). We also see in Grayson's work an admirable willingness to bridge the digital-analog design, to bring into his rigs the best of the old and the new. Thanks Grayson!
Grayson writes:
An Evolution of Thermatron Homebrew Techniques
For a long time I have been trying to develop some techniques to prototype Thermatron projects as easily as the typical “Manhattan style” solid-state construction. Thermatron projects you see now-a-days still use the traditional technique of mangling aluminum-drilling and mounting everything to a “bud” style chassis. This just takes too much time and my projects always look disappointing.
Fortunately, around two years ago, Rex Harper, W1REX, came to the rescue after hearing an earlier talk of mine and developed a set of thermatron socket pads. The MeTubes panel from QRPme consists of 10 prototype pads for thermatron sockets. The panel has v-scores for breaking the panel into single tube pads. The panel has pads for mini 7 & 9s, octal, compactrons and acorns. Awesome.
The best sockets to use with the pads are PCB style. These provide a large pin area to bend out and solder to the pad (see photos).
I pre-mount a dozen or so of the 7-pin and 9-pin sockets on MeTube pads so I have them ready to go when prototyping. The “crude” example below shows and 7 and 9-pin socket on one of my prototypes. I think this was a microphone amp for my AM transmitter. Pardon the mess.
The nice thing about the pads is that they provide plenty of room to tac solder lots of parts to a single pin–easy to add or remove parts. This is a lot easier than using the traditional tube socket pin.
Prototyping thermatrons in this way is FAST. No more punching out holes to hold thermatron sockets in aluminum chassis!
But it is still nice to be able to have the thermatron on the “top” of the board and the components on the “bottom” of the board. To do this and still use the MeTube pads, the thermatron has to be mounted on the other side. I did this by mounting the socket through the MeTube pad. This requires making a hole in the center of the pad to pass the socket through and then soldering the pins in the usual way. This is way easier with PC mount thermatron sockets and make a very nice installation.
This technique has some great advantages over using the traditional socket with pins. The pad has a lot more room to mount components to each pin. Normal thermatron socket pins are difficult to attach more than two wires and it’s a bit more difficult to get a good solder connection. The pads are easy to solder to and allow components to be easily attached in any direction since the “socket” is now flat.
It is also easy to attach the socket/pad to a copper clad board. The same hole must be made in the copper clad board to pass the top of the socket through, then the pad is superglued to the board in the regular way.
This is another example of “right side up” thermatron mounting on a prototype test board for crystal filters. I mounted a small “plug board” (not sure what you call these things) in the center to allow me to easily swap filter components. Notice the acorn thermatron soldered direct to the pad. The board works great, the filter design sucked. I gave up. Maybe too much distributed C.
I used this technique, combined with Roger Fell’s idea of using inverted aluminum chassis, to build my latest project, a QRP AM/CW transmitter. I’ve been wanting to try out a few new ideas and this seemed like a good project to try them on. I also wanted to build the transmitter in modular “blocks”, interconnected in a similar way to Rogers. It worked pretty good although I am still trying to get the thing to work right. Even new construction techniques can’t cure my screwups. BTW, the ANALOG VFO is ROCK SOLID. +/- 10 Hz over 30 min. Even I was impressed. The Hartley oscillator is the best circuit for thermatron circuits by far.
I’ll send an update when I get it fully working on AM and CW.
Jun JH8SST made this nice video about his version of Pete Juliano's Simpleceiver. I like the approach of putting the stages on separate boards, but perhaps Jun could have made things easier by using Manhattan-style construction on those boards. And of course I like the breadboard-style aluminum sheet. FB Jun. Jun writes:
I've built a simpleceiver, which is a modified version. My first main board didn't work because of several problems, and that's why I decided to divide the board into several separated PCB's with some circuit modifications.
RF and Mixer stages are original, but I employed an 8pole 9MHz ladder Xtal filter. The J310 X 2 is used in IF amplifiers, but load resonant circuit is modified to use a type 10K coil form and a ceramic capacitor.
J310 product detector is original and built on a tiny PCB, as shown in attached photo and YouTube Video.
This modified Simpleceiver has high sensitivity and more than enough gain. I needed to reduce RF/IF gain to eliminate product detector distortion caused by stronger signals.
This simpleceiver works really nicely.
I'm going to re-modify it to make it as original as possible.
The block diagram is: J310X2 RF－DBM－9MHz 8 pole X'tal Filter－J310X2 IF－J310X2 IF－J310 product detector－AF μA741－AF LM380 with NFB.
I'm going to re-modify it as: J310X2 RF－DBM－J310X2 IF－12MHz 4 pole X'tal Filter－J310X2 IF－J310 product detector－AF μA741－AF LM380 with NFB.
I'm also going to add an AGC system using a modified W1FB AGC circuit.
Much to the consternation of Pete "Digi" Juliano, I have been working on analog LC VFOs for simple superhet receivers. As described in earlier posts, I recently converted an old Barebones CW superhet to 40 meter SSB. At first, the VFO (2 -2.3 MHz) was not stable enough -- it would slowly drift in frequency. ("We have a solution for that," chuckled Pete.) My first effort at stabilization involved replacing the toroidal coil. The material in the core is sensitive to temperature changes and this can lead to instability. I found my traditional cardboard tube from a coat hanger, and made a coil of the needed inductance (you can see it in the pictures). This yielded some improvement in stability, but it was still drifting. Next I tried taking out all the silver mica and disc ceramic caps in the LC circuit of the oscillator and replacing them with NP0 ceramic caps. The feedback caps are in the box below the tuning cap, but you can see some of the little NP0s on the outside of the box, connected to a rotary switch. This serves as the equivalent of variable "Bandset" variable cap, with the tuning cap serving as the "Bandspread." I have seven switch positions, each covering about 40 KHz (with some overlap). This gives me all of the phone band and the bottom 30 kHz of the CW band. Switching to NP0 caps really did the trick. The receiver is now very stable. When I told Farhan about my VFO woes, he mentioned that he'd had very good stability results with surface mount caps. I wonder if this success has more to do with those caps being NP0 than with their surface mount configuration. Here is a good description of NP0:
NP0 Ceramic Capacitors are single-layer ceramic capacitors made from a mixture of titanates.
A NP0 ceramic capcitor is an ultrastable or temperature compensating capacitor. It is one of the most highly stable capacitors. It has very predictable temperature coefficients (TCs) and, in general, does not age with time. NP0 stands for negative-positive 0 ppm/°C, meaning that for negative or positive shifts in temperature, the capacitance changes 0 part per million, meaning that it has a flat response across a wide range of temperatures; the capacitance of the NP0 capacitor stays constant (at the same value) despite variations in temperature. From: http://www.learningaboutelectronics.com/Articles/What-is-a-NPO-ceramic-capacitor
But I think it is a stretch to claim that these marvelous caps do not "age with time!" That would be a really astounding property of the titanium dielectric. That would be a Negative-Positive Zero FLUX capacitor, right?
My wife and I went to see this flick about the mathematician Srinivasa Ramanujan. It was filmed at Trinity College, Cambridge -- if you look at the dedication to "SolderSmoke -- Global Adventures in Wireless Electronics" you will see a picture of my kids at Cambridge. Alas, that picture was taken at Kings College, not Trinity; nonetheless, the Cambridge connection got us interested. Then there was the Indian aspect of the story, which is very intriguing. There was also the "amateur makes good" angle that all of us should, I think, find very encouraging.
The movie did not disappoint. We really liked it. The presentation of the cultural clash was very well done. Elisa told me that as she watched Ramanujan struggle with England, she found herself wanting to tell him, "You are just going through culture shock. Be patient! I've been through this many times!" They included just enough math to give the viewer a sense of what Ramanujan was working on. I got a real kick out of one scene in which old Professor Hardy, seeking to motivate young Ramanujan, took him into the Wren Library and showed him the manuscript of Newton's Principia. I had seen the same manuscript in the library of the Royal Society in London -- they had take it out on the occasion of the visit to the library of Stephen Hawking and NASA Director Mike Griffin. They also had on the table the reflecting telescope that Newton himself had made. That was quite a day.
Great movie. I give it the coveted rating of five soldering irons.
I sat in the shack this morning with a cup of coffee, mesmerized by the things Pete was saying. I actually took notes. Some highlights:
-- In describing his zeal to avoid the use of store-bought components, Pete acknowledged that there are limits to this. But then he revealed that his limits are different than those of even the most fundamentalist of homebrew fundamentalists: "Well, I'm not going to mine my own copper." Don't worry Pete -- no one will call you an appliance operator if you use store bought wire.
-- On the same subject, when describing his homebrew diodes for crystal radios, Eric asked Pete why he didn't just go out and buy a Germanium Diode. "That would be cheating," replied Pete. Indeed.
Wow, Rex Harper W1REX deserves some sort of big award. I hereby grant him the coveted Brass Figlagee with Bronze Oak Leaf Palm, but that is clearly not enough. Rex spent a month of 20 hour days putting together kits for the Four Days in May QRP event at the Dayton Hamvention. The results were spectacular: 246 hams succeeded in building QRP transmitters, and they all did it in under 70 minutes. Just as impressive as the results were the ways in which Rex overcame the technical and organizational hurdles prior to the event. You can read all about this in Rex's excellent write up: http://www.qrpme.com/docs/FDIM%202016%20Report.pdf
The OFFICIAL SolderSmoke Correspondent at Dayton was once again our friend Bob Crane, W8SX. Bob caught up with Rex and somehow managed to get him to stand still long enough to do this interview:
And it was very nice that Rex did this as a tribute to Dave Ingram K4WTJ whose magazine articles about simple QRP rigs inspired many of us. Years ago, right after completing a homebrew QRP transceiver, I talked to Dave on 30 meter CW and told him that his articles had helped motivate me to build.
Finally, no SolderSmoke post about Rex would be complete without a repetition of the video showing him transferring the prodigious mojo of the original Tuna Tin Two into my BITX-17 transceiver.
John:
For the last couple of mornings you have been coming in quite strong on 40 meters around dawn here. Attached is a short video from today. I am listening with a homebrew superhet receiver:
sTef DL1FDF/VY1QRP alerted us to this multi-band Michigan Mighty Mite beacon project out of Sweden. They certainly have some fine looking rigs! Check out the reports: http://www.radiorud.se/fyren.php
I remember reading an outraged letter in a stereo magazine back in the 80's, right after CD's came out. The writer had condemned a particular CD player for having a single digtal-to-analog converter that was time-shared between the two channels, consequently inducing an "unlistenable" phase error in the audio. An engineer (and I hope a ham!) wrote in to observe that this was indeed correct, but helpfully noted that the phase error could be corrected by moving one of the speakers about a half inch farther away from the listener. That's noodling! :-)
And you might enjoy this article:
...Some audio scams are so blatant you wonder how anyone could fall for them, like a replacement volume control knob that sells for $485. The ad copy proclaims, “The new knobs are custom made with beech wood and bronze … How can this make a difference??? Well, hearing is believing as we always say. The sound becomes much more open and free flowing with a nice improvement in resolution. Dynamics are better and overall naturalness is improved.” ...
James Randi, magician and hoax-buster, had a standing offer of $1M to some makers of "paranormal" audio equipment, like $700/foot cable, if they could prove it was better in blind A/B testing. Nobody took him up on it.
Second Anniversary of Pete Juliano's arrival on the SolderSmoke Podcast. Dayton and FDIM underway Bench Reports: Pete: -- Repurposing old Circuitry -- Pete's small Display -- New Transmitter -- LBS in Japan and at Dayton Bill: -- S38-E The lipstick has worn off. -- Reduction drive for the Mighty Midget's Mate -- Back to the Barbados Barebones Receiver: Which LO to use for 40 Meters with a 5 MHz IF? Sideband Inversion and "Lower Sideband" filters. Eradicating WWV with parts from AA1TJ Improving VFO stability A bandspread/bandset arrangement with fixed caps Soul in the Old Machine "The Amateur is FRIENDLY..." MAILBAG
"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
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