Ham Radio in China -- Interesting info from 高大伟 David Cowhig

Chinese Radio Licenses and Operating Certificates

David Cowhig (aka WA1LBP,  aka Gao Da Wei) was Hambassdor for 73 Magazine on Okinawa when I held a similar "position" on the island of Hispaniola.  David is a real Asia hand, and is fluent in both Mandarin and Japanese.   He is uiniquely sitated to provide info on ham radio in China.  In a recent post he provides this info, and describes how we may soon be hearing from ham Taikonauts in space:  

https://gaodawei.wordpress.com/2024/05/22/2024-ham-radio-in-china-soon-chinese-hams-in-space/

Thanks David! 

"The New Essential Guide to Electronics in Shenzhen" A Book Review by Jenny List (with a video from Shenzhen)

This new book looks really good.  Great electronics info, with lots of cultural and linguistic wisdom. 

https://hackaday.com/2024/03/13/review-the-new-essential-guide-to-electronics-in-shenzhen/#more-668397 

Jenny's review brought to mind an older SolderSmoke blog post about Shenzhen. In this 2012 video  Bunnie Huang in Singapore talks about getting parts in that city: https://soldersmoke.blogspot.com/2012/08/singapore-knack.html

Thanks to Jenny, Naomi, and Bunnie.  

IMSAI Guy Looks at Counterfeit Chips

Like some of the commenters, I had been scratching my head wondering why someone would go to all the trouble of counterfeiting electronic parts.  It just didn't seem to make economic sense.  Perhaps they were just marketing factory rejects?   But no,  IMSAI Guy shows in the video above that it is a lot more insidious.  It turns out that this kind of crime DOES make economic sense (see comments).  So be careful out there. 

Here is another one IMSAI Guy did yesterday, looking at other faked chips: 

Thank you IMSAI Guy! 

7J6CBQ on Okinawa -- And a Translation of a Science Fiction Novel about Ham Radio in China

 

The article about Sergeant Malik Pugh USMC on Okinawa brought back memories from the 1990s. David Cowhig was 73 Magazine's Hambassador on Okinawa -- I had the same "position" in the Dominican Republic.  David and I were both in the Foreign Service;  we joked that 73 had afforded us our only chances to be ambassadors of any kind.  David's Okinawa QSL and the opening from his initial report to 73 magazine appear above.  You can see more here: 

https://archive.org/details/73-magazine-1992-12/page/82/mode/1up

• https://archive.org/details/73-magazine-1993-04/page/82/mode/2up
• https://archive.org/details/73-magazine-1993-04/page/84/mode/2up
• https://archive.org/details/73-magazine-1993-04/page/86/mode/2up

https://archive.org/details/73-magazine-1993-06/page/76/mode/2up

https://archive.org/details/73-magazine-1993-07/page/82/mode/2up

https://archive.org/details/73-magazine-1993-08/page/78/mode/2up

https://archive.org/details/73-magazine-1993-11/page/84/mode/2up

https://archive.org/details/73-magazine-1993-12/page/78/mode/2upmode/2up

A couple of my own "dispatches" as Hambassdor to the Dominican Republic appear here: 

https://www.gadgeteer.us/DRDISP.HTM

Back in the 90's David sent me an old QST Magazine.  I wrote about this on the SolderSmoke blog: 

https://soldersmoke.blogspot.com/2015/07/been-there-done-that-he-begged-his.html

Later, I learned about another "Hambassador" who was still active as a radio amateur: Ron Gang 4X1MK:  

https://soldersmoke.blogspot.com/2017/10/ron-gang-4x1mk-on-qso-today-podcast.html

Finally (and this is really cool):  David Cowhig has been putting his language skills to good use, translating Chinese written material.  He sent me his translation of the opening chapters of a Chinese science fiction novel about ham radio.   Readers of the SolderSmoke Daily News will like this: 

https://gaodawei.wordpress.com/2021/12/18/chinese-sf-ham-radio-web-novel-we-live-in-nanjing/

We Live in Nanjing 《我们生活在南京》

Thanks David! 

Other Workshops: Genius Girl Fixes (Re-builds!) Old Tractor

This is amazing.  I put it in the "other workshops" category, but when you watch this you will see that she re-builds this tractor with NO WORKSHOP AT ALL.  It seems to be done at roadside and on the front yard of her house.  With some very basic tools. 

I would be a complete mess if I tried this.  And I would fail to get it going. 

I have posted about Lin's projects before.  See:  https://soldersmoke.blogspot.com/2022/04/the-next-time-you-hear-someone.html

Here is her channel: https://www.youtube.com/@LinGuoErOfficial

Polyakov (RA3AAE) Direct Conversion Receiver: 40 meter DC RX with VFO at 3.5 - 3.6 MHz (with video)

I've been reading about Polyakov (or "sub-harmonic") Detectors for a long time: 

https://soldersmoke.blogspot.com/search/label/Polyakov--Vladimir

But until now, I never built one.  Recently,  Dean KK4DAS and the Vienna Wireless Makers group have been building a Direct Conversion receiver.  Their receiver uses an Si5351 as the VFO, but of course Dean and I have decided to try to do things the hard way by building non-digital VFOs.  At first we just came to the conclusion that my earlier Ceramic Resonator VFO wasn't much good (it drifted too much).  This led us into standard Colpitts and Armstrong VFOs, and the fascinating world of temperature compensation.  Then I remembered the Polyakov circuit -- this would allow us to use a 3.5 MHz VFO on the 7 MHz band.  Lower frequency VFOs are easier to stabilize, so I started building my first Polyakov receiver.  You can see the results (on 40 meters) in the video above. 

I started working with a circuit from SPRAT 110 (Spring 2002). Rudi Burse DK2RS built a Polyakov receiver for 80 and 40 that he called the Lauser Plus.  (Lauser means "young rascal" or "imp" in German.) For the AF amplifier, I just attached one of those cheap LM386 boards that you can get on the internet.  With it, I sometimes use some old Iphone headphones, or an amplified computer speaker. 

The Polyakov mixer is a "switching mixer."  The book excerpt below shows how I understand these circuits.  The enlightenment came from the Summer 1999 issue of SPRAT (click on the excerpt for an easier read): 

Leon's circuit shows us how a simple switching circuit in which the switches are controlled by the VFO can result in an output that has the sum and difference components. That is the hallmark (and most useful part) of real mixing.  Remember -- we say that mixing happens in non-linear circuits when the passage of one signal depends on what is happening with the other signal.  A switch is as non-linear as you can get! And that switch is being controlled by the VFO.  

In a Direct Conversion receiver we usually run the VFO at the operating frequency. This results in audio just above and just below the operating frequency. 

The Polyakov Direct Conversion circuit is a bit different.  It has the switches (the diodes)  turned on twice each cycle:  When the VFO voltage goes to a positive peak, this turns on one of the diodes.  When the VFO goes to a negative peak, this turns on the other diode.   So in effect the switch is being turned on TWICE each cycle.  So with the Polyakov you run the VFO at HALF the operating frequency.  For a DC receiver designed to run around 7.060 MHz, you build a VFO at around 3.53 MHz.  This has some immediate advantages.  My favorite is that it is easier to get a VFO stable at a lower frequency.  It is easier to stabilize a VFO at 3.53 MHz than it is at 7.060 MHz. 

When you open that SW 1 switch in the Lauser Plus, you no longer have a Polyakov mixer.  Now you just have a diode mixer.   It will be opening and closing once each cycle at the VFO frequency.  DK2RS used this to cover not only the 40 meter band (in Polyakov mode) but also the 80 meter band (in single diode detector mode).  That is why DK2RS has that big variable capacitor in the input circuit -- that LC circuit needs to tune all the way down to 3.5 MHz and all the way up to around 7.3 MHz.  (I used a coil of about 6.5 uH to do this.) 

With just one diode and operating at 80 meters, it works, but not as well as it does in the Polyakov mode on 40.  I can pick up 80 meter signals, but in this mode there seems to be more of an "AM breakthrough" problem. "Experimental Methods in RF Design" on page 8.11  describes what is going on (the last sentence is most relevant here): 

Here are some very good links with information on the Polyakov receiver: 

LA8AK on Polyakov: http://noding.com/la8ak/c21.htm

LA8AK's Home Page: http://www.agder.net/la8ak/index1.htm

LA8AK SK: http://www.agder.net/la8ak/   Almost seventeen years after his death he continues to help his fellow radio amateurs through his web sites.  TNX OM!  FB! 

BH1RBG: https://sites.google.com/site/linuxdigitallab/rf-ham-radio/dc-polyakov-based-first-dc-receiver

Hack-A-Day on Polyakov: https://hackaday.com/2015/11/15/polyakov-direct-digital-synthesis-receiver/

I will post a video tomorrow showing the receiver in operation on 80 meters.  

Three cheers for Vlad Polyakov, RA3AAE

The Next Time You Hear Someone Complaining About Winding Toroids....

... send them this video. 

Lin is in Hong Kong. What a great job she does with very simple tools.  Notice how she casually mentions that for those parts that have been lost, she will make them herself.  Three cheers for Lin! 

This video reminded me of the people in Santo Domingo 25 years ago who rewound the transformers and RF chokes from my HT-37.  These parts still work.  

Chuck KF8TI recently told me that when he was a Peace Corps Volunteer in the Philippines (1965-1967) he visited a transformer re-winding shop there, seeing piles of insulation and wire on the floor.  Apparently business was good!  

Lin's YouTube channel: https://www.youtube.com/channel/UCpPt42tLH5FRk__ytvMsejw

The (Real) Solar Flare of August 1972 in Cixin Liu's Science Fiction

 

A view of McMath Region 11976 from the Paris Observatory early on 4 August 1972. 

I have a vivid memory of seeing -- as a kid -- Aurora from our home near New York City.  Eric Carlsen, my childhood friend and colleague from the Waters Edge Rocket Research Society,  told me his mom had similar memories. A while back I did some Googling and concluded that it had to have been the monster solar flare of  August 1972:

 https://soldersmoke.blogspot.com/2009/09/carrington-flares-aurora-where-were-you.html    

That blog post got about eight comments, mostly from other folks with similar memories -- they apparently were led to my blog by the same kind of memory-based Googling that I had done. 

This year, on Christmas Eve, Elisa and I were flying home from the Dominican Republic. I was reading (on my phone) "To Hold Up the Sky," an anthology of Cixin Liu's science fiction short-stories.   I'd read his excellent "Three body Problem" in the Dominican Republic back in December 2017.   His work is usually "hard" sic-fi, with a strong connection to real physics.

One of the short stories in the anthology is entitled "Full Spectrum Barrage Jamming." Wow, I thought, that one is really promises to be very interesting for a radio amateur.  I turned out that it was more interesting than I expected. 

I won't spoil the story for you.  Suffice it to say that Cixin Liu makes reference to the same August 1972 solar flare that I remember from my childhood, and discusses its effect on radio propagation.  It was really kind of eerie to be in that plane, flying over the Bahamas, reading Chi-Fi on my I-phone, and seeing the author reference that memorable event from 1972.  TRGHS. 

There were plans to turn this story into a movie: https://www.yicaiglobal.com/news/wandering-earth-producer-to-film-another-liu-cixin-novel

Here is an excellent article describing what happened back in 1972: https://room.eu.com/article/lessons-from-the-sun.   The August 1972 flare was so strong that it caused U.S. Navy anti-ship mines to explode in Haiphong harbor in Vietnam. 

Some Initial Thoughts on FT-8

 -- This is really interesting technology.  Three cheers for Joe Taylor and colleagues.  This mode would obviously be very useful for fast, weak signal contacts as are needed on meteor scatter or EME. 

-- FT-8 does give you the chance to work DX that would have been difficult on other modes. 

-- Chinese hams showing up on FT-8 -- more than other modes. 

-- I think FT-8 is good for hams who just want to have a lot of "contacts." It is definitely not for the rag-chewer. 

--  I find it it kind of cold and antisocial.  More like a computer game than ham radio. A bit like sending  short text messages on a cell phone. 

--  I think FT-8 contacts are in some ways more meaningless than a "59!" contest exchange -- unless you look, you don't even know the report you got,  nor do you know the report you sent. 

--  For me it is more impersonal than CW.  But at least we let the technology decode the characters instead of having to memorize dot and dash sounds.  In a phone contact you can hear the other person's laugh.  In a CW QSO, you hear him key "HI HI."  FT-8?  No laughter at all. 

-- With PSK Reporter, FT-8 gives you a good feel for how propagation changes during the day. But it is kind of like 2-way WSPR.  As with WSPR, it is -- at first -- fascinating, but then it loses its charm. Yes, everyday you are heard in Belgium. 

-- It seems to be getting kind of crowded.  The passband for FT-8 contacts is often full, and it is hard to find an open space.

-- There is little opportunity for the homebrewer.  I hooked it up to my homebrew transceivers and had a small bit of fun using a 2N3904 as a switch triggered by the RTS signal for T/R.  But that's about it. 

-- I get the sense that the ham himself is not really needed in FT-8.  This mode seems like it could easily be automated or run by an AI.  Just tell it to go out there, make a lot of contacts and log them.  Maybe prioritize the DX you "need."  Has this already been done? 

--  After a session with FT-8, I had a really nice 17 meter ragchew SSB QSO.  That SSB contact left me happy.  The FT-8 session was a bit like spending time on social media or a video game.  It left me edgy.  FT-8 made me appreciate phone even more.

But hey, to each his own.  A lot of people really like FT-8.  I hope they have fun. 

Kintsugi -- A Japanese Philosophy for the Owners of Imperfect Rigs

 On Sun, Aug 29, 2021 at 4:05 PM Bob Scott wrote:

Hi Bill:

   After listening to the latest Soldersmoke I thought you might find the Japanese concept of "kintsugi" (literally "golden joinery") interesting.  

 

    From Wikipedia:  https://en.wikipedia.org/wiki/Kintsugi#Philosophy

       As a philosophy, kintsugi is similar to the Japanese philosophy of wabi-sabi, an embracing of the flawed or imperfect.[11][12] Japanese aesthetics values marks of wear from the use of an object. This can be seen as a rationale for keeping an object around even after it has broken and as a justification of kintsugi itself, highlighting the cracks and repairs as simply an event in the life of an object rather than allowing its service to end at the time of its damage or breakage, and can be seen as a variant of the adage "Waste not, want not".[13]

  Kintsugi can relate to the Japanese philosophy of mushin (無心, "no mind"), which encompasses the concepts of non-attachment, acceptance of change, and fate as aspects of human life.[14]
 

  Not only is there no attempt to hide the damage, but the repair is literally illuminated... a kind of physical expression of the spirit of mushin....Mushin is often literally translated as "no mind," but carries connotations of fully existing within the moment, of non-attachment, of equanimity amid changing conditions. ...The vicissitudes of existence over time, to which all humans are susceptible, could not be clearer than in the breaks, the knocks, and the shattering to which ceramic ware too is subject. This poignancy or aesthetic of existence has been known in Japan as mono no aware, a compassionate sensitivity, or perhaps identification with, [things] outside oneself.

 — Christy Bartlett, Flickwerk: The Aesthetics of Mended Japanese Ceramics

73,

  Bob KD4EBM

--------------------------------------------

I shared Bob's Kintsugi message with David, WA1LBP.  David was one of the few radio amateurs in the ranks of the Foreign Service.  He was in Okinawa during the early 1990s, when I was in Santo Domingo.  For a time we both wrote columns in the "73 International" section of Wayne Green's magazine -- this made us "Hambassadors."  David is a real scholar of difficult Asian languages.  During my last years in government service I would sometimes cross paths with David at lunch time on the National Mall in Washington -- he'd be out there with a colleague, studying ancient Chinese poetry. 

Here are David's thoughts on this: 

Thanks,  Hambassador Bill.

In Buddhism, muxin (in Chinese wuxin) is about freeing oneself from troubling thoughts, distractions, and selfishness and so attaining a calmness that is very aware of all that goes on at the same time.  I suppose once free from distractions one can be more alert.  So maybe not literally no mind but no-selfish-obsessed-mind

Amazing what one can find online. A distraction too I suppose!

https://plato.stanford.edu/entries/buddhism-chan/

Chan embraced this account of nonduality and Buddha-nature, but distinctively used it to qualify the meaning of Buddhist practice and the personal ideal of the bodhisattva. In the Platform Sutra attributed to Huineng, he insists that

meditation is the embodiment (ti) of wisdom, and wisdom is the functioning (yong) of meditation.

The point of Chan is to see one’s own “original nature” (benxing, 本性) and realize “authentic heartmind” (zhenxin, 眞心), and in doing so the dualities of thought and reality, of passion and enlightenment, and of the impure and pure all dissolve. Then,

true suchness (zhenru, 真如) is the embodied structure (ti) of thinking, while thinking is the functioning (yong) of true suchness. (Platform Sutra, 13–17)

To see our own original nature is to see that true suchness and thinking are as intimately related as the bodily structure of a horse and its customary activities. Just as the bodily structure of the horse establishes the conditions of possibility for grazing and galloping, it is only the proven evolutionary advantage of grazing and galloping in horse-like ways that have made this bodily structure possible. True suchness or ultimate reality is not a preexistent something “out there” that can be grasped intellectually or accessed through some mystical vision; it can only be enacted.

Huangbo Yixun (d. 850) describes this as demonstrating no-“mind” (wuxin, 無心) or freedom from conceptual impositions that would define or limit reality. But this is not a lapse into mental blankness or indiscriminate presence. Realizing no-“mind” restores our originally whole mind (yixin, 一心) that Huangbo qualifies as the “silent bond” (moqi, 默契) of “conducting oneself as all Buddhas have” (in Taishō shinshō daizūkyu, Vol.48, 2012.380b to 383c). Significantly, the term “qi” originally referred to notches or tally marks on a strip of bamboo that record the terms of a trade agreement and the bonding that Huangbo invokes is thus one of mutually entrusted obligation and responsibility. True suchness consists in the personification of the bodhisattva ideal of realizing liberating forms of relationality. Ultimate reality consists in enacting the morally-inflected nonduality of wisdom and compassion.

David 

-----------------------------------------------------

I remember that it was George Dobbs, G3RJV who introduced us to the concept of Wabi sabi:

https://soldersmoke.blogspot.com/2010/04/homebrew-hero-george-dobbs-g3rjv.html

This philosophical embrace of imperfection and repair is very appealing to me.  I am surrounded by old radios that bear the marks of wear, tear and repair.  My homebrew radios are filled with imperfections (especially in the cabinetry).   But Kintsugi tells me this is all OK.  I accept it. 

Thanks Bob.  Thanks Hambassador David. And thanks to George Dobbs. 

A Step Closer to the Elser-Mathes Cup? Ham Receives Signals from Mars

 

That is the antenna that Scott Tilley VE7TIL  used to receive signals from the Chinese spacecraft Tianwen-1 in orbit of Mars.  In a recent SpaceWeather article, Scott comments on the importance of SDR receivers in these deep space reception efforts.  

https://spaceweatherarchive.com/2021/02/16/ham-radio-signals-from-mars/

I've been watching the Elser-Mathes cup for a long time. I dedicated my book "SolderSmoke  -- Global Adventures in Wireless Electronics" to my kids, Billy and Maria, noting that they were both possible future winners of this most prestigious award.  Scott Tilley's work has put us a step closer to an award ceremony for some intrepid radio amateur. 

Here is a good article on the Elser-Mathes Cup: 

http://www.arrl.org/files/file/QST/This%20Month%20in%20QST/June2016/Schoenfeld.pdf

Scott was in the news last year for finding a zombie satellite: 

https://soldersmoke.blogspot.com/2020/04/quarantine-search-for-zombie-satellite.html

Glowing Numerals for the Lafayette HA-600A (With Jeweled Movements)

 

I really like this receiver.  I have strong sentimental ties: it was my first SW receiver.  But the frequency readout situation was kind of rough -- depending on where you put the Main Tuning cap, your Band Spread dial could be WAY off.  

China to the rescue!  Specifically the very nice San Jian PLJ-6 frequency counter boards.  I have used these in several projects.  I like them a lot. I get mine on e-bay.  They are very cheap.  Here is the manual with specs: 

https://www.mpja.com/download/35057tebasic%20manual.pdf

As I did with my BITX20, I put mine in an Altoids-sized box.  I got to use my Goxawee rotary tool with circular metal blade to cut the rectangular hole.  Hopefully future efforts will yield neater results, but the flying sparks were fun;  they made me feel like one of those car-part  "fabricators" on cable TV. 

To tap the VFO frequency, I just put a bit of small coax at the point where the 10 pf cap from the VFO circuit enters the first mixer.  I ran this cable to the unused "Tape Recorder" jack on the back of the Lafayette -- this connects to the input of the counter.  I attached 11 volts from the power supply to an unused terminal on the accessory jack of the Lafayette -- this powers the counter.

Having a counter on the VFO proved very illuminating -- in more ways than one.  I measured the Center Frequency (CF) of my IF to be at 456 kHz.  I set the PLJ-6 to display the VFO frequency MINUS 465 kHz.   For AM broadcast signals, this worked fine:  I'd tune the signal for peak S-meter reading.  This meant that the carried was right at the CF.  

For SSB, things were a bit different.  I set the BFO knob  to be RIGHT AT 465 kHz when the dot is in the center position.  With the BFO there, I could tune in SSB signals.  The suppressed carrier would be right at the center of the IF passband, with the audio information above or below the suppressed  carrier frequency.  But it didn't sound good this way -- it sounded better if I would tune an LSB signal 2 kHz down from the center, then adjust the BFO down about 2 kHz.  This put most of the the audio in the peak portion of the IF filter(s) curve.  Doing it this way means that I have to remember that the number displayed on the PLJ-6 is 2 kHz down from the actual suppressed carrier frequency of the transmitting station.  I can live with that.  

I am going to leave the Lafayette on the corner of my workbench so that I can easily tune in hams  and SW broadcast stations.  Having modified the product detector and added the digital frequency readout makes listening to this receiver even more pleasing.  The jeweled movements are as smooth as ever. 

So 2021 is off to a good start on my workbench.  HNY to all!  

Receiving Signals from China's Chang'e-5 Lunar Sample-Return Mission

Background info: 

https://www.scientificamerican.com/article/chinas-change-5-mission-launches-to-collect-lunar-samples/

 A great report from Daniel Estevez EA4GPZ on radio amateurs receiving telemetry from Chang'e-5: 

https://destevez.net/2020/11/a-look-at-change-5-telemetry/

HP8640B Internal Frequency Counter Fixed (More Repairs Pending)

 

The HP8640B is a complicated machine.  Above you see just one sub-assembly, and the page from the manual that describes it.  This is what I've been working on.  The little spring "tine" fell out of one of those discs behind the two control knobs.  So I had to open this thing up, find the spot from which the tine had fallen, and glue it back in.   

I used Gorilla Super Glue, followed 24 hours later by a dab of JB Weld "minute weld" dual epoxy. One of the other tines was about to fall out, so I went ahead and gave all the tines in this assembly the glue treatment.  ( I bought some "Weld On" acrylic cement but the warnings on the label were quite sobering.  So I left that can sealed up.) 

This morning I put the thing back together.  This is not easy.  At one point a spring popped and a tiny metal part that is probably irreplaceable seemed to fly away into the black hole that is the shack's carpet.   I had just about given up hope when I found the thing sitting right in front of me on the bench.  TRGHS. 

The HP8640B fired up right away without trouble and the internal frequency counter is working fine. 

As I noted in the last SolderSmoke podcast, a very nice community devoted to the HP8640B has developed around the world.  Here are some of the notable participants: 

Bill at Electronics Revisited is a very nice fellow with lots of experience on the HP8640B.  He offered to sell me a replacement unit for the assembly pictured above.  If you have an ailing HP8640B and are looking for someone to work on it for you, Bill is the guy you should talk to:  http://www.electronicsrevisited.com/  He also very kindly offers to answer any questions you may have about the HP8640B. 

Here is the e-bay page of the fellow in Bangalore who makes the brass gears.  Mine are on the way! 

https://www.ebay.com/usr/engineeringideas?_trksid=p2047675.l2559

Marcus VE7CA has a great site devoted to the HP8640B: https://www.ve7ca.net/TstH86.htm

BH1RBG in China has a nice site describing his adventures with the HP8640B: https://sites.google.com/site/linuxdigitallab/home/hp8640b-20v-power-supply-down

K6JCA has a good blog post about fixing the tines and the gears: 

http://k6jca.blogspot.com/2018/09/repair-log-hp-8640b-rotary-switches-and.html

Steve Silverman (who gave me this HP8640B) found a really useful  history of the device: 

http://hpmemoryproject.org/timeline/bob_devries/some_memories_05.htm#part_05_chapt_09

And of course special thanks to Dave VE3EAC who alerted me to the falling tine problem and put me on the path to a successful repair.  

The gears should be here in a few weeks, so that will be another opportunity to work on this HP8640B.  Also there are some tines in the attenuator assemby that might reinforce with the glue treatment. 

The Agony of Troubleshooting -- From China

 

I am troubleshooting my beloved NYC HP8640B Signal Generator (thanks to Steve Silverman and Dave Bamford).  Some of you may wonder why I don't just replace this beast with something small, lighter, cheaper and newer.  Well, I have not found any new sig generators that will do what this beast does:   It goes all the way up to 256 MHz (higher with an extension kit).  It has a great attenuator in it so you can set the output just where you want it.  AM or FM modulation.  Really useful.  So I think I'll fix it. 

My problem is that the internal freq counter stops working above 16 MHz. Using the very extensive  documentation, and without even really opening up the machine, I think I have located the fault.  I think it is in the Counter Time Base Assembly board A8A3.   Now of course, the fun begins.  (Tips, advice, solutions, and words of encouragement would all be appreciated.) 

While planning my assault on A8A3, I came across the web site of BH1RBG.  He too has recently been working on an HP8640B.  His problem was different, but when I read through his site I saw evidence that the agony of troubleshooting is something that is the same all around the world.  Check out his description of the agony: 

I even suspected the LM723 should had something bootstrapping circuit, make sure the Q4 sure start. Because the external reference VR3 is floating too, oh, my godness.

I became hopeless, and ordered several LM732,and waiting delivery for days. This beast frustrate me so deeply, changed the LM723 does not help anything. And i almost desoldering everything in the board!

Oh man, I've been there. Several times while in the throes of a troubleshooting battle I have actually had dreams of removing all the parts from a troublesome PC board.

BH1RBG has a very interesting site with lots of ham radio projects: 

https://sites.google.com/site/linuxdigitallab/rf-ham-radio?authuser=0

SolderSmoke Podcast #224: Mars. Spurs. Bikes. SDR. NanoVNA. Antuino. MAILBAG

SolderSmoke Podcast #224 is available:

http://soldersmoke.com/soldersmoke224.mp3

1 August 2020

--The launch of Perseverance Mars probe with Ingenuity helicopter.

--China’s Tian Wen 1 on its way – radio amateur Daniel Estevez EA4GPZ is listening to it! 

--Sci Fi Books:  Mars Trilogy by Kim Stanley Robinson.  No skip on Mars :-(

--We have some sunspots!  SFI now 72 and the Sunspot number is 23. 

Bill's bench: 

--Conquering Ceramic Spurs in Q-31   Roofing filter -- sort of 

--NE602 for a Q-75 converter – Gilbert Cell. 

--Measuring low power levels out of NE602.  Antuino better than 'scope . 

--NanoVNA   Really cool stuff.  SDR in there. 

--Building a 455 kc LC filter from QF-1 rubble. Using LTSPICE, Elsie... 

--Reviving my bicycle AM radio – The “All Japanese 6”

--Understanding L Network impedance matching. 

--Bill’s new resistor kit from Mouser. Thanks to Drew N7DA. 

SHAMELESS COMMERCE:  PATREON, AMAZON SEARCH.  THANKS

Pete's Bench: 

--Lockdown Special 

--BPF work on SDR Rig

--I U W I H 

Mailbag:

VK3HN Summit Prowler 7

VK2EMU “The Stranger”

SM0P  HB uBITX in Dubai

AE7KI  Worked him in VK from London

ON6UU  EA3GCY’s 4020 rig

KA4KXX A Simpler Mighty Mite

W9KKQ M19 DMR

KD4PBJ Radio Schenectady

W3BBO 12AU7 Regen

KE5HPY Another 12AU7 regen

N5VZH Ne602 Converter

KY3R Wall Art

G4WIF  Spectrum Analyzer in your pocket

W2AEW  Talks to UK Club

KK0S Sent 455 Kc IF cans

KL0S Making 9Mhz filters

VU2ESE  Diving into simple SDR schemes

Dean KK4DAS  Amateur Radio Astronomy

Blog -- "Chinese Electronics Products Tested"

I was looking for information on my  FeelTech FY3200s Signal Generator.  I came across a very informative blog; it covers a variety of other Chinese gear and parts.  

Here is the Feeltech FY3200S article: 

https://chinese-electronics-products-tested.blogspot.com/p/fy3200s-function-generator-tested.html 

Here is the home page of the blog: 

https://chinese-electronics-products-tested.blogspot.com/

And here is backround information on the author: 

Thanks Jos! 

Chinese Micro-Satellite Photographs Eclipse -- FROM THE MOON

Back in October 2018 I posted about this Chinese satellite: 

https://soldersmoke.blogspot.com/2018/10/chinese-amateur-satellites-orbiting.html 

From:https://www.newsnation.in/science-news/chinas-lunar-orbiter-captures-epic-images-of-earth-during-solar-eclipse-article-229818.html  :

According to report by Xinhua, a microsatellite developed by the Harbin Institute of Technology in northeast China's Heilongjiang Province, which is now orbiting the moon, captured mesmerizing photos of Earth during the solar eclipse in the early hours of Wednesday (Beijing time).

It is to be noted that the microsatellite, weighing 47 kg and named Longjiang-2, was sent into space on May 21 last year, along with the Chang'e-4 lunar probe's relay satellite dubbed as "Queqiao" and entered lunar orbit four days later.

According to the research team from the Harbin Institute of Technology, the microsatellite carries a mini CMOS camera that only weighs 20 grams, which makes it easy to operate, and it can take pictures at short intervals.

“Since the camera uses an automatic exposure mode, the camera's field of vision must contain a certain area of the moon to realize correct exposure. When the recent total solar eclipse occurred, the orbiter was flying over the far side of the moon. In the few minutes before and after the moon blocked the earth, all the conditions were right to take the pictures,” Xinhua further quoted the team as saying.

According to the team, to avoid becoming space rubbish, the microsatellite will be controlled to crash into the moon after it stops operation at the end of July.

As per Xinhua, the team cooperated with amateur radio operators in Spain and Germany in taking and receiving the photos. Nearly two pictures taken by the microsatellite during the solar eclipse were sent back to Earth on Wednesday. 

Chinese AMATEUR Satellites ORBITING THE MOON! Radio Amateurs Receiving Images

This is really amazing and deserves more attention than it has been getting.  

http://www.spaceflightinsider.com/organizations/china-national-space-administration/contact-lost-with-chinas-dslwp-a1-lunar-microsatellite/

https://amsat-uk.org/tag/dslwp/

https://gbtimes.com/radio-enthusiasts-receive-new-earth-and-moon-images-from-chinese-microsatellite-in-lunar-orbit?fbclid=IwAR2eUGeyyDK7FgalitW5xQxY7TEekbTxRSwg17uwWrEdzBduGQdfARqHfFo

https://twitter.com/bg2_cry

https://twitter.com/bg2bhc

https://space.skyrocket.de/doc_sdat/dslwp-a.htm

https://destevez.net/2018/06/dslwp-b-detected-with-7-element-yagi/

Video on PCB Factory in China

This factory is a LONG way from Manhattan -- both from the island and from the technique.  

How about some Juliano Blue PC Boards?   

The machine that automatically checks for bad connections was especially amazing. 

And the boards are made in 24 hours, with 3 day shipping to the U.S.