Podcasting since 2005! Listen to Latest SolderSmoke
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.