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Thursday, November 5, 2020
Peter Sripol's Electric Ultralight (and his workshop)
Monday, November 2, 2020
Our Editorial on the U.S. Election
In our last podcast we took a few minutes to share with our listeners our views on the U.S. election and who we think they should vote for. Here is the text of what we said. We stand by every word.
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Just days before a very important U.S. election we feel obligated to express our opinion and to let our listeners in the U.S. know who we think they should support.
Some of you will think this is inappropriate -- we
disagree. Several of the long-running
and more recent themes of SolderSmoke are wrapped up in this election:
SolderSmoke is all about global community, the
International Brotherhood of Electronic Wizards. Trump just rejects the idea of global
community. He is all about building walls, imposing travel bans, rejecting
refugees, circling the wagons, and blaming our problems on foreigners. This is one of the reasons we oppose him.
SolderSmoke is all about Science and Technology. Trump is
anti-science. He is a climate change
denier. That's another reason we oppose him.
Speaking of science, since the onset of the pandemic we
have been urging SolderSmoke listeners to protect themselves, their families,
and their communities by following the advice of doctors and scientists. We urge them to socially distance, and to
wear masks. We even invented an acronym in support of this -- SITS – “Stay In
The Shack.” Incredibly, Trump has been
pushing in the opposite direction: He ridicules
the use of masks. He calls our leading
doctors "idiots." He stages super-spreader
events at his rallies and at the White House. Look, more than 200,000 Americans
have been killed by this thing. I know
five people who have buried close relatives.
Yet Trump STILL treats this virus as some sort of political hoax. This is one of the many reasons we oppose
him.
We are both military veterans. We have both been offended by the way Trump
-- who is a draft dodger himself -- has disparaged those who have gone into
harm's way for the United States. We
remember what he said about John McCain.
His scorn for veterans and service members is another reason we oppose
him.
There are many other reasons to oppose Trump, but those are
the ones we feel are most relevant to SolderSmoke.
Election day is Tuesday.
PLEASE, for the good of the country and the world, get out there and
vote against Trump. Wear your mask and stay safe as you do so, but get out and
vote. Especially if you are living in
Florida, North Carolina, Georgia, Pennsylvania, Wisconsin, Michigan, Arizona,
Texas, or Omaha, Nebraska, please help vote Trump out of office and please urge
your friends and relatives to do the same.
Saturday, October 31, 2020
SolderSmoke Podcast #226 The U.S. Election, Solar Cycle, uSDX, Hermes, HP8640B, SGC 600 Sig Gen, HA-600A, Mailbag
SolderSmoke Podcast # 226
http://soldersmoke.com/soldersmoke226.mp3
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About the U.S. election
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Mars: Setting early, will have to shift to evening observation. Weather has been poor.
Sunspot Cycle 25 is underway -- SFI 78, SN 32
The Gliessberg cycle
Pete's Bench: #49, #50, uSDX, Hermes Lite
Bill's Bench: HP8640B, Global Specialties Corp 6000 counter, Lafayette HA600A.
MAILBAG:
Peter VK2EMU Sent me copy of 1947 Handbook. Thanks Peter
Brad W1BCC Spotted 10 S-38s for 80 bucks on Craig’s list. What’s going on here?
Dale K9NN sent both Pete and I care packages with very cool part, including DG Mosfets
Stuart ZL2TW sent me Les Moxon’s Antenna Book. TRGHS. Moxon will be back!
Alvin N5VZH got his receive converter with a little Tribal Knowledge from SS.
GM4OOU The Bitsy DSB rig from Scotland
Peter VK3YE DSBto DC incompatibility SOLVED
Paul VK3HN's Digital SWR and Power Meter and Low band AM TX VFO/Controller FB Videos.
VK2BLQ alerts us to article about Jac Holzman of Elektra Records.
AA0ZZ great message on assembler language and writing software the hard way.
Tuesday, October 27, 2020
Monday, October 26, 2020
VK3YE: Solving the Direct Conversion RX -- Double Sideband TX Incompatibility Problem
Sunday, October 25, 2020
Saturday, October 24, 2020
On the Cover of The Rolling Stone (Almost) -- Jac Holzman, Elektra Records, and Ham Radio
ARRL reports that his callsign was K2VEH.
Hey, Pete plays guitar. So does Farhan. Should we have our people call Jac's people? Maybe do lunch?
Wednesday, October 21, 2020
Listening in on the Deep Space Network
Not long ago we took the DISH satellite antenna off our roof. For a while I resisted pleas to put the big thing on the curb for pickup. I fantasized about using it for radio astronomy. In the end, I threw it away. I do have VHF/UHF aspirations, but being able to use that dish just seemed to be something in my distant future (if ever!).
But check out what David N2QG is doing with his dishes: He is listening to very distant spacecraft normally picked up only by NASA's Deep space network. Very cool. Truly inspirational.
Here are the links:
http://www.prutchi.com/2020/10/15/recap-of-x-band-dsn-activities-and-plans-for-the-future/
http://www.prutchi.com/wp-content/uploads/2020/10/DSN_Lessons-_Learned_N2QG.pdf
Thursday, October 15, 2020
Too Simple? Deficiency of the Lafayette HA-600A Product Detector?
I've been having a lot of fun with the Lafayette HA-600A receiver that I picked up earlier this month. Adding to the mirth, I noticed that on SSB, the signals sound a bit scratchy, a bit distorted, not-quite-right. (I'm not being facetious; this is an interesting problem and it might give me a chance to actually improve a piece of gear that I -- as a teenager -- had been afraid to work on.)
Before digging into the circuitry, I engaged in some front panel troubleshooting: I switched to AM and tuned in a strong local AM broadcast signal. It sounded great -- it had no sign of the distortion I was hearing on SSB. This was an important hint -- the only difference between the circuitry used on AM and the circuitry used on SSB is the detector and the BFO. In the AM mode a simple diode detector is used. In SSB a product detector and BFO is used. The BFO sounded fine and looked good on the scope. This caused me to focus on the product detector as the culprit.
Check out the schematic above. Tr-5 is the product detector. It is really, really simple. (See Einstein quote below.) It is a single-transistor mixer with BFO energy going into the base and IF energy going into the emitter. Output is taken from the collector and sent to the audio amplifiers. (A complete schematic for the receiver can be seen here: https://nvhrbiblio.nl/schema/Lafayette_HA600A.pdf )
I had never before seen a product detector like this. One such detector is described in Experimental Methods for RF Design (page 5.3) but the authors devoted just one paragraph to the circuity, noting that, "We have not performed careful measurement on this mixer." The lack of enthusiasm is palpable, and probably justified.
A Google search shows there is not a lot of literature on single BJT product detectors. There is a good 1968 article in Ham Radio Magazine: http://marc.retronik.fr/AmateurRadio/SSB/Single-Sideband_Detectors_%5BHAM-Radio_1968_8p%5D.pdf It describes a somewhat different circuit used in the Gonset Sidewinder. The author notes that this circuit has "not been popular."
To test my suspicion that the product detector is the problem, I set up a little experiment. I loosely coupled the output of a signal generator to the IF circuitry of the HA-600A. I put the sign gen exactly on the frequency of the BFO. Then, I switched the receiver to AM, turning off the BFO and putting the AM diode detector to work. I was able to tune in the SSB signals without the kind of distortion I had heard when using the product detector.
So what do you folks think? Is the product detector the culprit? Or could the problem be in the AGC? Should I start plotting a change in the detector circuitry? Might a diode ring work better?
Monday, October 12, 2020
Quino, The Creator of Mafalda ("BASTA!") RIP
Putting "Basta" in the SolderSmoke search box yields many blog posts. The cry of ENOUGH! from six year-old Mafalda has been part of the podcast for many years and is now part of the SolderSmoke lexicon.
https://soldersmoke.blogspot.com/search?q=Basta
We don't do a lot of obits on this blog (we try to keep it all upbeat) but the passing of Mafalda's creator Quino is news that many of you may have missed, and that I think merits mention here. This link has a nice 3 minute report from NPR:
https://www.npr.org/2020/10/04/920038792/mafalda-cartoonist-quino-dies-at-88
Adios Quino. Gracias por todo.
Sunday, October 11, 2020
Ryan Flowers' Admirable Approach to the BITX40 Module
We must remember that Farhan designed the BITX transceivers -- and especially the BITX40 Module -- in the hope that these rigs would encourage hams to tinker, to modify, to change and to repair. When I read Ryan Flowers' blog post, I thought that Farhan's mission has been accomplished.
https://miscdotgeek.com/bitx40-rebuild-part-1-mistakes-planning-and-teardown/
I was also struck by how nice it is that Ryan has a sentimental attachment to this BITX40 module because it was a gift from his wife. That's the kind of thing that gives a piece of electronic circuity soul.
Above we see Ryan's module with many of the parts removed in the sections that he feels he messed up. This is obviously a good approach, but it reminded me of the nightmare I've had (and I am not the only one) where, in frustration, I take ALL the parts off a recalcitrant board.
Stick with it Ryan! You are on the right track. And it sounds to me like you WILL soon be homebrewing from scratch your own SSB transceiver.
A while back we built a blog with many nice mods for the BITX40 Module:
http://bitxhacks.blogspot.com/
Saturday, October 10, 2020
Chip Replaced, GSC 6000 Counter Fixed
This thing has been half-broken for a long time. I needed to get the input for 40 MHz - 650 MHz working I got the a replacement SP8630B Plessey divide-by-ten counter chip on e-bay, and yesterday I extracted the old chip and put in the replacement. I took great care NOT to solder this one in upside down (as I had done with another chip replacement in this counter). I used solder flux and solder wick to gradually get the pins free of the board. (You can see the old chip in the picture above.)
As to what happened to the original SP8630B chip, John over on the Vintage Test Gear Facebook page wrote:
The Plessey SP8630A/B is an ECL divide by 10 prescaler, with a upper working frequency of 600MHz. That generation went out of production in the late 1980s. Plessey was bought by a Canadian company now called Micrel. You may be able to find one from one of the specialist obsolete component companies, but it may be dead on arrival. Those ECL ICs had a fairly high mortality rate if they are very old.
It is the old story of "metal migration". In early semiconductors very small impurities in the silicon structure cause minute bits of the metallisation to leach out into the essentially non-conducting silicon insulation. Many old devices, although they have never been used, were found to be very leaky and this degrades the gain of the active devices. The worst types are the very old Germanium transistors.
As the semiconductor scientist learnt more about the super cleanliness required and the better purification of the metals the problem tended to improve. The Marconi company I worked for back in the 1980s had a real problem with comms satellites failing after a few years of service. Of course you can't go up there and swap out the faulty devices. Accelerated ageing of a backup satellite showed that some devices just stopped working after being subjected to high and low temperature cycling, which is a common problem with satellites in orbit!
I am liking this little machine more and more. It is very simple -- no microcontroller, just a collection of gates. I discovered that the main main crystal oscillator is actually built inside a little oven to keep the temperature stable -- oscillator and the oven stay on as long as the counter is plugged in, even when the device is switched off. I calibrated the counter with WWV and with my HP8640B and with my little Feeltech sig gen counter. I wish I knew how to calibrate the counter in the Rigol DS1102E oscilloscope.
Friday, October 9, 2020
The Bitsy -- Homebrew Double Sideband from Scotland
This is such a beautiful project: it involves DSB, homebrew, troubleshooting, George Dobbs, SSDRA, J310s, a box kite, and ham radio nostalgia. I was struck by how similar the Bitsy looks to some of my own DSB creations (but the Bitsy is nicer). I'm really pleased to find a DSB project coming out of the UK -- when I was there, DSB was kind of frowned upon by spectrum preservation zealots. I say there is plenty of room for the very few homebrew DSB rigs that will ever grace the airwaves with their presence. Thanks John. Have fun with all your projects. 73 Bill
Hi Bill
In the early 80's I built and experimented with Direct Conversion Receivers and had a lot of fun with them. I came across a 40M DC cw transceiver by the late Rev. George Dobbs in a Practical Wireless magazine and decided to build it. Whether I was just lucky I'm not sure but it worked first time and I had several cw contacts with it. It was called “The PW Severn”. I then discovered DSB and looked into modifying the wee rig. I gave George a phone, no internet in those days, and explained what I was proposing to do and if there was any advice he could offer. His reply was , “it should work so try it and see, any problems get back to me”. It worked and I had a lot of fun with it. I used to take it portable and with a box kite to support a long wire and worked all over Europe.
It was after reading and learning about
circuits and home brewing I wondered if I could design and build a DSB
transceiver of my own. I had plenty of articles and most importantly a copy of
Solid State Design, now well thumbed.
So the “Bitsy” was born. It is an 80M DSB
transceiver. The PA produces about 2 watts. I took what I thought was the best
for each module and built it using six circuit boards which I designed and
etched myself. Nowadays I use the Manhattan method for one of circuits. It is
much easier and quicker.
Like most home brew projects, the fun is in
the building and the wee rig lived in a box for several years. Probably over
30. My doesn't time fly. I came across it again while looking through my boxes
and decided to give it an airing. Expecting it to work on power up I was quite
shocked when it produced nothing on both receive and transmit. After staring at
it for a couple of minutes I unscrewed the lid and studied the wiring for a dry
joint. Nothing so I switched on my Digital Multimeter and Oscilloscope. I soon
found out that the output from the VFO was missing. The VFO uses one FET and
two PNP Transistors for the buffers. The scope soon proved that the FET was
faulty. I used an MPF102. These are hard to get so I replaced it with a J310.
While I had the VFO out I also replaced the 9.1v zener diode, which provides a
regulated voltage for the FET, with a 78L05 connecting the centre pin via a
580ohm resistor to earth. This gives me a 9.3v regulated supply for the
oscillator. It is now back in full working condition.
With the Covid 19 epidemic I, like a lot of
the Amateur Radio fraternity, am spending a lot of time in the shack and
looking for new projects. I am buying back my old FT200 which was my first rig.
An old friend and lapsed amateur has still got it and agreed to sell it back to
me. It is still in a good condition for being nearly 50 years old and just
needs some TLC. When it is finished it will take pride of place beside my
restored Heathkit SB104A. And they say nostalgia is not what it used to be!!
John Forsyth
GM4OOU
Thursday, October 8, 2020
HA-600A Gets a New Coat of Paint -- After Almost 50 years!
Wednesday, October 7, 2020
Solar Cycle 25 - The Gleissberg Cycle Dashes Hopes for a Big Solar Max
Tuesday, October 6, 2020
TRGHS -- My First SW Receiver Offered FREE for Pickup -- The Lafayette HA-600A (Looking for Globe VFO Deluxe)
Sunday, September 27, 2020
A Suitcase Portable 40 Meter CW Station from 1951
Wow. Check this out:
http://www.skywaves.ar88.net/homebrew/W9FKC.pdf
A very nice rig built by an amazing homebrewer
And thanks to Al Klase N3FRQ for putting that wonderful web site together.
Thursday, September 24, 2020
Global Specialties Corporation 6000 Frequency Counter -- Anyone have a Plessey SP8630B Chip?
Continuing my effort to improve my workbench and its test gear, this week I turned to an old frequency counter that I picked up at the Kempton Park Radio Rally in London many years ago. It was not working when I got it, but long-time SolderSmoke listeners will recall the tale of woe that resulted from my having soldered a replacement IC (that Tony Fishpool G4WIF had sent me) UPSIDE down. Tough times my friends, tough times.
Well, I'm working on it again. First I converted it from 220 to 110 power. I had a transformer in the junk box that fit nicely, both electrically and mechanically. In the course of doing this, I learned something about this counter that I did not know: As long as it is plugged in, even if you turn it off, the time-base oscillator keeps running. And get this Color Burst Liberation Army members: The oscillator runs at 3.579545 MHz. TRGHS.
With sunspots scarce and with Pete pessimistic about the solar cycle, VHF and UHF now seem more interesting. I need to have more test gear for the higher frequencies. This counter works up to 650 MHz. Yea!
When I first fixed this thing, I was quite pleased to get it going with "Input A -- 5 Hz to 100 MHz." But now I want to get "Input B -- 40 MHz to 650 MHz" working also. I used a 50 MHz signal from my newly repaired HP-8640B to trouble shoot Input B. I think one of the divider chips is bad. It is a Plessey SP 8630B. Does anyone have one of these chips in their junk box?
Wednesday, September 23, 2020
Wisdom from AA0ZZ: NO LIBRARIES! ASSEMBLER CODE ONLY! -- "Digital Crap" -- "No Magic Fruit" What qualifies as a real rig? Si570 vs. Si5351
Bill,
Why do you guys make your Soldersmoke podcasts so darn intriguing such that I can’t listen to them in the background while I’m doing something else? Good grief! I start listening and before long you make me stop and chase down a rabbit hole to find something new that you mentioned that I had no clue was out there. Before long I’m doodling out a new sketch or playing with at a new design for something I really need to experiment with or build “next” or something I need to try. It is taking too much of my time!! J
I’ve been listening to your podcasts for years. Way back, before I knew you and before I knew you were doing these Soldersmoke blogs with Mike, KL7R, and just before he was so tragically killed, I was collaborating with him on a simple frequency counter project using a PIC microcontroller. We were making good progress on a neat design. I later completed the project but always kept his contributions noted as part of the source code.
I’ve been making PIC-based VFOs for years – dating back to about 2000 – aiming them at builders who were looking for something to go along with Rick Campbell’s (KK7B) receivers. Rick is a good friend now, after we met in the Kanga booth at Dayton where we both were demonstrating our stuff. (Bill Kelsey (N8ET) of Kanga, was the “marketer” for my kits as well as Rick’s for many years.) My original VFO kits used a DDS (high-end AD9854) that simultaneously produced I and Q signals which made it perfect for Rick’s phasing gear. Rick is a big supporter of my work but he still kids me about polluting his beautiful analog world with my “digital crap” (copyright KK7B term). When I came out with a newer version VFO using a Silicon Labs Si570 PPLL (I can hear already Pete Juliano groaning) it was a big improvement over the AD9854 in noise/spur reduction. I documented this all in a QEX article in about 2011 and Rick (and Wes Hayward) were very supportive/appreciative of my work.
I have used the Si5351 also and I understand Pete’s point of view. It’s “plenty good” for most amateur projects. However, it remains a fact that the Si570 is a better part and produces a cleaner signal. That’s the reason why the Elecraft KX3 uses a Si570. Granted, the newer Elecraft KX2 uses a Si5351 but it’s most likely because they wanted to preserve battery life (the Si570 uses more power but not nearly as much as the AD9854) and also to reduce the cost. I do understand! I also fully understand the ability of the Si5351 to produce I and Q signals via different channels. I’ve had extensive conversations about this with Hans Summers, at Dayton and online. I use a pair of Flip-Flops on the output of the Si570 instead. My PIC code driving the Si570 is ALL written in ASSEMBLER code. Yep! I’m an EE but have had a career mainly in software development and much of it was writing assembler code. I dare say there aren’t too many gluttons for punishment that do it this way. I do it because I want to understand every line of code don’t want to be dependent on anyone else’s libraries. Every line of code in my VFO’s and Signal Generators is MINE so I know I can debug it and it can’t get changed out from under me. (This problem bit Ashar Farhan hard on the Raduino of his BitX. Tuning clicks appeared because the Si5351 libraries he used changed between the time he tested it and released it. I was really appalled when I dug into this and resolved to NEVER use libraries that I didn’t write myself. Similarly, this also makes me have some distaste for Arduino sketches. I would rather see ALL of the code including the initialization code, the serial routines, etc, rather than having them hidden and get pulled in from Arduino libraries. That’s similar to the reason why Hans Summers didn’t use an Arduino in his QCX. He used the same Atmel microprocessor but developed/debugged it as “C” code with the full Atmel IDE/debugger.
By the way, Pete mentioned the Phaser FT8 transceiver by Dave, K1SWL, in a recent podcast. Dave is a very close friend, even though I haven’t met him in person since about 2000. We Email at least daily and some of it is even about radio. J I did the PIC code for the tiny PIC that controls the Si5351 in the Phaser. Yes, it’s written entirely in Assembler again! I do know how to do it for a Si5351. That Si5351 code is not nearly as much “fun”, though. I know, this will make very little difference to guys who write Arduino “C” code to control it but under the covers it’s a world of difference. It takes me about 15 serial, sequential, math operations to generate the parameters for the Si5351. None of them can be table driven and they all have to be performed sequentially. (This is all hidden in about 5 lines of complex, Arduino “C” code but the operations are all there in the compiled assembler code.) In contrast, my Si570 code is almost all table driven. I just have to do one large (48-bit) division operation at the end to generate the parameters. Yes, that’s a bit of trickery to do in ASM. There are no libraries do this.
I will point out one more advantage of the Si570 in comparison to the Si5351. It has the ability to self-calibrate via software instead of relying on an external frequency standard. In my Si570 app I can read up the exact parameters for the crystal embedded inside the Si570, run my frequency-generating algorithm “backwards” and determine the exact crystal frequency (within tolerances, of course) for that particular Si570. Then I update all the internal tables using that crystal frequency and from then on all generated frequencies are “exact”. I love this! Frequency often moves by about 6 kHz on 40M.
Oh yes, I must mention the difference of home solderability of the si570 vs the Si5351. Those little Si5351 buggers are terribly difficult to solder at home while the Si570 is a breeze. I know, many folks will just buy the AdaFruit Si5351 board and it’s already soldered on but, again, I like to do it all myself. No “magic Fruit” for me.
Now that I retired a couple of years ago and am getting out of the VFO kitting business I can finally build complete rigs instead of just making the next-generation VFO’s for everyone else to use. I recently build a tiny, Direct Conversion rig with a Si570 signal generator (of course) and a diode ring mixer (ADE-1). Look at my web page, www.aa0zz.com to see it, along with my VFO projects that I’ve been building in the past. As you well know, Direct Conversion is fun to build and the sound is astounding; however, they are rather a pain to use! Yes, I did make it qualify as a real rig by making several contacts all over the country. (Wes Hayward gave me the criteria: he told me that I must put any new rig on the air and make at least one contact before it qualifies as a real rig.)
The new rig that’s on my workbench is my own version of a phasing rig, experimenting with a Quadrature Sampling Detector (QSD, sometimes called a “Tayloe” mixer), using some ideas from Rick’s R2 and R2Pro receivers and many innovations of my own. At present my new higher-end Signal Generator works great, the QSD receiver works great (extremely quiet and MDS of -130 dB on 40 meters) and the transmitter is putting out about 16 watts with two RD16HHF1’s in push-pull. You can take away my “QRP-Only-Forever” badge too, not that I’ve ever subscribed to that concept! Still more tweaking to do with the TX but now I’m also working on the “glue” circuitry and the T/R switch. The SigGen, RX and TX are all on separate boards that plug into a base board which has the interconnections between boards and the jacks on the back. I’ve built DOZENS of variations of each of these boards. Fortunately they all fall within the size limit criteria to get them from China at the incredible price of $5 for 10 boards (plus $18 shipping) with about 1 week turnaround. Cost isn’t really an object at this point but it’s more of getting a hardware education that I sadly missed while I concentrated on software for so many years. it’s certainly nice to have willing mentors such as Rick, Wes, Dave (K1SWL), Don (W6JL) and many others to bounce my crazy ideas off. Yes, I’m having a ball!
I was licensed in 1964 but out of radio completely from 1975 to 1995. Do you like the picture of my DX-100 on my web page? My buddy in the 60’s had a Drake 2B and I drooled over it but couldn’t afford one.
Now I must finish this rig before you guys send me down another rabbit hole. Too many fascinating things to think about! I literally have a “priority list” on the my computer’s desktop screen. Every time I come up with a new project idea – something I really want to play with such as a Raspberry Pi, SDR, etc, I pull out the priority list and decide where it fits and what I want to slide down to accommodate it. That’s my reality check!
Take care, Bill. Thanks for taking the time to give us many inspiring thoughts and ideas.
73,
-Craig, AA0ZZ
Monday, September 21, 2020
HP8640B Internal Frequency Counter Fixed (More Repairs Pending)