FDIM 2024 Interview with Farhan VU2ESE

Thanks to Bob Crane W8SX we have some great interviews with those who made presentations at the Four Days in May event (FDIM 2024).  Sorry for the long delay -- it is all my fault, but I have excuses.  Our thanks to Bob W8SX, our correspondent at the FDIM event.  

Here is the interview with our friend Farhan, VU2ESE, the ham who has brought so much homebrew goodness to the hobby, starting years ago with the BITX 20 schematic. 

http://soldersmoke.com/FarhanVU2ESE.mp3

Thanks Bob!  Thanks Farhan! 

Video Update on the Mythbuster II 20 meter SSB Transceiver

I have added the transmit circuitry. I described building practices. We listen to the receiver again. I talk about plans for transmit/receive switching. After this I will build another CCI 100 watt RF amplifier for use in the Dominican Republic.

For the first look at this rig see:

https://soldersmoke.blogspot.com/2024/10/bill-n2cqr-builds-yet-another.html

 We will discuss this further in an upcoming Ham Radio Workbench Podcast, and in SolderSmoke Podcast #254 (mid-November 2024) 

Bill N2CQR Builds Yet Another Mythbuster Transceiver

 This one is for 20 meters (no need for 75) and will go to the Dominican Republic.

6 crystal filter at 5.2 MHz. VFO from old Yaesu FT-101 Termination Insensitive IF amplifiers using boards from Mostly DIY RF No RF amp ahead of the mixer. First mixer is homebrew diode ring. Bandpass filter has 4 LC circuits. Steep skirts. Low insertion loss. Bal Mod/Product detector has two diodes (singly balanced) Carrier osc is crystal controlled and homebrew. Audio amp starts with a 2N3904 amplifier followed by an LM386 board. Transmitter portion will be done next.

The crystal filter as seen on the Antuino

Filter on the blank board. 

Bandpass filter (-20 db = 0)

VFO box, carrier osc, Bal Mod/Product Detector, AF amps

The Antuino looks at the Crystal Filter

Monitoring Maritime Radio Messages with YADD

 

Click on the image for a clearer view

This is really cool and very easy.  Easy nerd thrills.  

On Friday, Steve VE7SL, put up a blog post on how we can relive the glories of our youth by monitoring HF long-distance maritime traffic.  In the old days the ships were on CW and many report that it was great fun to listen to the various "fists" in action from coastal stations, and from ships on the high seas.  While the CW is long gone, this maritime traffic is still on the air.  Today they are using a SEL call system called Digital Selective Calling or DSC.  

Happily, it is very easy to decode these transmissions.  Steve recommends a program called YADD (Yet Another DSC Decoder).  I downloaded it in seconds and had it installed on my computer in minutes.  Next I had to find a general coverage receiver.  I thought about pressing my old HQ-100 into service, or maybe even the S-38E, but a cooler head prevailed.  I remembered that Farhan had given us a general coverage receiver in his uBITX transceiver.  So it came off the shelf and got powered up.  Around dawn on October 14, 2024 I put the receiver on 8.415 MHz LSB.  I didn't even have to do a real connection to the computer -- I just put the speaker close to the mic and that was sufficient.  

Boom.  Soon I was getting signals from ships afloat and from coastal stations.  I heard Shanghai, New Zealand, and Australia.   See above.   From the U.S., I heard Miami, but the most emotional for me was hearing the station at Pt. Reyes, in California.  This is the station that Dick Dilman W6AWO has volunteered at for many years.  FB.  

Back in 2017, Steve had another post on DSC and YADD: 

https://ve7sl.blogspot.com/2017/08/yadd.html

Thanks Steve! 

This site explains very well what DSC is.  From this I think we can see that there is nothing illegal about using YADD to monitor the DSC alerts (that are all emergency-related):  https://infoshipping.tripod.com/gmdss_dsc.html

Homebrew Receiver -- AG5VG's 20 Meter "Mythbuster" Receiver

Michael has the receiver done and is wisely heeding Farhan's advice about pausing to enjoy the homebrew sounds.  

I was pleased to see someone else using the FT-101 VFO.  Great piece of gear.  

On to the transmitter!  

AI Podcast #2: Here is Another Short Podcast ABOUT SolderSmoke.

Click here for the second "About SolderSmoke" podcast. 

 http://www.soldersmoke.com/About SolderSmoke 2.mp3

This one looks not at the SolderSmoke Daily News blog, but instead at the SolderSmoke podcast itself.

I was delighted to see the inclusion of Pete, Dean, Farhan and Mike Rainey!   This was really great.  

Look, it is not perfect.  There are errors.  But probably about the same number of errors that you would get from real, human hosts, right?    Voltaire told us not to let the perfect be the enemy of the good.  And I find this to be amazingly good. Look, it is so good that it is kind of scary, right?

Before you get too critical realize how this has been done:  I did nothing more than load the SolderSmoke Podcast Archive website into GPT-like model. Then I asked it to produce a deep dive podcast.  That's it.  About 5 clicks.  It developed the podcast in about 3 minutes.  I did the same thing yesterday but with the SolderSmoke blog.  And this is only the beginning.  

A Paraset and the Heathkit SG-6 Signal Generator (Video)

Mike WU2D put out this nice video (above) about whether or not he should part out his Heath SG-6 signal generator, using the parts in a Paraset construction project.  I faced a similar question years ago: 

https://soldersmoke.blogspot.com/search?q=SG-6

I just solid stated the SG-6.  I was influenced by Farhan and the drinking straws that he picked up with his kids at a McDonalds in Hyderabad. 

As with the QF-1, I say to Mike: GO FOR IT OM!  You need those parts for other projects.  Don't feel bad about the SG-6.  But keep that switched coil assembly -- it is quite useful. 

Field Day with Farhan, his Family and an sBITX Near Hyderabad, India

Farhan and his son Rayyan with an sBITX

The SolderSmoke crew thought it had a tough time this Field Day:  Pete N6QW had hoped to do something, but was stymied by hot California weather.  Dean KK4DAS had even worse weather.  Bill HI7/N2CQR was at a remote QTH with an HW-8 and a wire antenna -- he managed just ONE contact (W7RN in Nevada on 15 CW).  But none of us had as much trouble as our friend Farhan had.   In  his account of Field Day in Hyderabad, we see an intrepid ham standing up against the slings and arrows of outrageous fortune that Field Day often throws at true radio amateurs.  Here is Farhan's Field Day story: 

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

You asked for it, so here it goes...

I got the chance last evening to head out to our farmland. My daughter Ramsha had her friend were over. By the time we all got into the SUV, it was already 5:30 pm. I had loaded in the Spiderbeam fiberglass pole, the sbitx with LiPo battery and an EFHW ATU strapped on, into the back into my backpack,  the toolbox with a few hand tools.

On the way to the farm, rain begin to come down. Rayyan (son, VU3ECQ) started said as much, I turned up the volume on Bruno Mars...

By the time we got to the farm, the rain was over(Ha!). We immediately begin to set up the antenna. I chose an inverted V config for the antenna and to use a tree as the support. The spiderbeam, as any who has been taken in by it knows, is a telescoping 33 feet high mast made of fiberglass. A curious villager decided to help us too. The girls had already taken off to pick the Mulberries.

So, Rayyan, the curious fellow, and I tried to telescope out the mast. The curious fellow, having never read the manual, picked up the mast from the wrong end and all the pieces fall out the other end. (Censored @#$%...). Within 15 minutes, we had all the pieces put back in the order of their thicknesses. I scotchtaped the center of the 66 feet wire to tip of the mast and we all hauled it up vertical. For those who don't forget maths, you can figure that two section of 66 feet wire will be exactly 33 feet high and when you tie this to the high end of a 33 feet high pole -- they just hang down vertically in a straight line. I was trying hard to remember the math teacher's name when the telescoping mast decided to untelescope into a 5 feet, collapsed height. My son commented that it has worked as advertised. Now, I wanted to remember my son's Moral Lessons teacher's name...

Next, we scotch taped the center of the 66 feet wire to approximately 2/3rd height. The curious guy and I walked it up back and took it to the tree. Rather we tried to. The branches kept getting in the way. Finally, managed to get within 4 feet of the trunk and I declared that we could just tie it up with the packing nylon rope bundle we were carrying. We did and it held up. 

By now, the two ends of wire had gotten all twisted around each other. We all had an excellent arm workout trying unwind them. The techniques -- never mentioned in any antenna handbook -- is to hold both ends of the twisted pair in one hand each, spread out your arms and make overhead sweeping motion to flick one wire over the other. This method only adds more twists into the wire. I discovered that wires could be twisted around each other both ways. There is no untwisting them. I discovered this amazing feature!

After watching us for 10 minutes, Humera, my XYL, asked us to forgive the world and bring down the mast and untangle the wires on the ground. By now, a stray cow had also sauntered in on her way back home. I think our language attracted her. She was bellowing for her calf to come and watch.

Next, we, efficiently undid the wire twists. Rayyan and the curious fellow held the two ends away from each other and I raised the mast. Or rather I tried to. At 45 degree tilt, the mast sections add up huge amount of weight. I was tottering around with it when it thankfully  leaned onto the tree branches. At this time, I declared it done. We tied the mast at 6 feet height by the rope to the tree trunk. One end went to the a branch of a bush and the other we walked to the point where it was taunt and touched the ground. 

I brought out the radio, much to the curious fellow's surprised, who was looking forward to me doing more entertaining things with the mast rather than a radio. We switched it on, I quickly peaked the ATU to maximum noise and keyed up. The sbitx shut off. Our battery was discharged.

An intrepid ham is never dissuaded by the flings and arrows of time which, when taken at a tide, leads to Field Day. I decided to move the operations to the farm cottage where we had power. But there was no supporting tree nearby. I decided to use the SUV as support.

We packed the SUV at an approximately correct distance from the vernadah of the cottage. We carried the mast over to the SUV and strapped it at two points: on the foot rest and on the overhead luggage rock. At this point the Spiderbeam fiberglass collaspible mast took a commercial break and demonstrated rapid collapse, into the much vaunted 5 feet size. Rayyan was rolling in the grass with mirth. This divided my anger between two opposing directions: toward  my progeny and toward my antenna mast. I didn't move.

I thought like an engineer.  The curious fellow and I carried the mast to an illuminated part of the farm, laid it down, and scotch taped each section to the next as the spiderbeam folks had warned us to do. It is strange how memory works better when your blood pressure is up. 

The mast went up again, this time strapped to the SUV's rack, door column, and the footrest. I setup the radio on a table outside the cottage, running the extension cord from inside. The SUV and the antenna were too far for the EFHW  to reach the radio. 

We asked Humera (XYL) and the girls who were watching us while having their mulberries to DO SOMETHING and not just SIT THERE. So, Humera got inside the SUV and started to roll it towards the cottage. A loud crunching sound announced the sad departure of the sunflower plants we had tied the other end of EFHW from  mother Earth. The EFHW had unrooted its support as the SUV pulled it away. These minor inconviences never deter a determine man, remember Gandhiji! 

Finally everything was in place, and we fixed up the rig but the microphone wouldn't key up. So what? I can just operate from the in-built mic and the thoughfully provided on-screen keyboard for CW, right? Well I could but I needed to key CW contiuously to set the SWR. So I opened up the mic. The curious fellow who had carried the radio to the new operating position was new to radio etiquette. He had just picked up the radio and walked, dragging the mic through the slush and weeds. The mic connector had come out.

I took the matters into my hands, by now, Rayyan was trying to show empathy for the old man by making loud noise like Aww! Shucks! and other unmentionables. I cut the cable with teeth, unbraided a small section and wired it up on the connector so I could short it to key the rig. Why can't the imbecile radio designers think of providing a tune button on the screen??

Finally, everything was in place. I tuned up and AIR net was on. This is the national evening SSB net on 7150. I tried breaking in with SSB a few times but didn't get through. Finally, I changed to CW and called. The net control asked "the CW station to QSY, this is the AIR net....". Finally some other SSB station who could copy my CW translated my CW to the net control and we had a three way contact.

At this point the girls declared we had to head home now that I had had my contact.

I was about to let out my public school vocabulary when I heard them say that they were hungry and there was lamb curry at home. The idea of getting back home and drying out, and eating the hot lamb curry and mangoes was too much for me. We folded up. But the mast refused to collapse. The curious fellow who had taken charge of the mast engineering had finally gotten hang of it. With superhuman strength, he had pulled the section of the mast out so tightly that no power on earth could potentially loosen them. I decided to trick the mast into thinking that we wanted it to stay up, so we put it back up vertically and slammed it into the ground. It dutifully woke up and demonstrated the much vaunted ability to fit back into a 5 feet tube.

I looked into the darkness to find the EFHW winder but I couldn't locate it. The curious fellow had left, scared by the racket the radio was making. The cow and the calf had gone home. We too headed back home. 

In the picture, you can see Rayyan standing while I am checking into AIR net. In the background is the SUV with spiderbeam fiber mast that is easy to carry in a 5 feet size.

73, de Farhan VU2ESE with a little help from my friends and family.

Farhan Talks Radio Tech at SolderSmoke HQ (EAST) (TWO VIDEOS!)

Great stuff!  We were really fortunate to have Farhan and Humera visit the SolderSmoke East shack after Dayton and FDIM.  Dean and I had a chance to talk BITX with the creator. Here is the two part video.  Most of the tech talk is in Part II (below).  

 

Farhan and his zBITX

Dean and Farhan with three sBITXs

Dean's homebrew sBITX

Farhan Phone

Old Tricks, Lore, and Art -- Freezing and Baking our LC VFOs -- An Example from Cuba

Pavel CO7WT explained why Cuban hams used a process of thermal endurance to improved the frequency stability of their homebrew rigs: 

  --------------------

I'm CO7WT from Cuba, I started my endeavor in ham radio with a islander board.

They (FRC, like ARRL but in Cuba) made a print of a PCB to build the Islander, with component numbers and values, making construction fool proof, I think it was on the 90 or end of the 80...

Mine was built with scraps from an old KRIM 218 Russian B&W TV as Coro's explain, later on I get the 6bz6 and 6be6 tubes for the receiver (this worked better than the Russian parts) the VFO was transistorized, made with Russian components. A friend CO7CO Amaury, explain me a trick: thermal endurance:

For a week put a crust of ice on the VFO board by placing it in a frosty fridge during the night. Put them in the sun by day. This indeed improved stability, this was an old trick.

By thermal endurance I mean improving thermal resistance vs tolerance, meaning that tolerance doesn't vary as much with temperature changes.

 It's crazy, but it worked!!

I remember that my vfo was on 7 MHz, with Russian kt315 as normal Russian transistors and capacitors, nothing 1-5%, 20% at most, it ran several khz in 5-10 min, mounted on a Russian "Formica" board (no PCB) and wired underneath.

After that treatment to the complete board with components and everything, including the variable capacitor; I managed to get it to "only" noticeably in the ear after 30-40 minutes.

To me it was magic!!

Basically, what I'm describing is just "thermal annealing", but Cuban-style and with more extreme limits.

In a refrigerator you could easily reach -10 c and in the sun for a day in Cuba 60-80 celsius at least.

In Cuba in the 1990s-2010s many designs of DSB radios proliferated, both direct conversion and super heterodine (using an intermediate frequency)

At first tubes and then transistors, mostly using salvaged parts, so it was common to find 465/500 kHz (if common Russian) 455 khz and 10.7 Mhz with or without "wide" filters since narrow filters for SSBs were not scarce: they were almost impossible to get.

Not only that, crystals, ifs, PCBs, transistors, etc.

Then, around the 2000s, Russian 500 khz USB filters began to appear (from Polosa, Karat, etc. equipment from companies that deregistered and switched to amateur radio) and that contributed to improving... Even though at 7 MHz 500kc if is very close.

I made many modifications with the years mostly from 1998 to 2004 ish... better filters in front of the first RX stage (same IF described between stages) improved selectivity and out of band rejection, remember we had on that days broadcast as low as 7100 khz

Tx part was a pair of russian 6P7 (eq. RCA 807) in paralell, etc.

The Jagüey and others is one of those evolutions...

 This is something I remember...

73 CO7WT

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

This is not as crazy as it sounds.  We can find versions of the same technique in the writings of Roy Lewellan W7EL, Doug DeMaw W1FB, and Wes Hayward W7ZOI.  I found this 2007 message from our friend Farhan VU2ESE: 

I think the word 'annealing' is a bit of a misnomer. the idea is to thermally expand and contract the wiring a few times to relieve any mechanical stresses in the coil. after an extreme swing of tempuratures, the winding will be more settled.
this techniques owes itself to w7EL. I first read about it in his article on the 'Optimized transceiver' pulished in 1992 or so.
but all said and done, it is part of the lore. it needs a rigorous proof.
- farhan

https://groups.io/g/BITX20/topic/copper_wire_annealing/4101565?p=,,,20,0,0,0::recentpostdate/sticky,,,20,1,860,4101565,previd%3D1193595376000000000,nextid%3D1194269624000000000&previd=1193595376000000000&nextid=1194269624000000000

And here is another example of coil boiling: 

https://www.qsl.net/kd7rem/vfo.htm

-----------

I can almost hear it,  all the way from across the continent:  Pete N6QW should, please, stop chuckling.  Obviously these stabilization techniques are not necessary with his beloved Si5351.  Some will see all this as evidence of the barbarity and backwardness of LC VFOs.  But I see it as another example of lore, of art in the science of radio. (Even the FCC regs talk about "Advancing the radio art." ) This is sort of like the rules we follow for LC VFO stability:  keep the frequency low, use NP0 or silver mica caps, use air core inductors, keep lead length short, and pay attention to mechanical stability.  Sure, you don't have to do any of this with an Si5351.  Then again, you don't have to do any of this to achieve stability in an Iphone. But there is NO SOUL in an Iphone, nor in an Si5351.  Give me a Harley, a Colpitts, or a Pierce any day.  But as I try to remember, this is a hobby.  Some people like digital VFOs.  "To each, his own." 

Thanks Pavel. 

A Contact with my Old Azorean DSB Transceiver

I've been thinking about balanced modulators, and I wanted to see how some of my early circuits performed.  So I pulled this OLD Double Sideband rig off the shelf and fired it up. The balanced modulator -- and everything else! - worked fine,  and I soon made contact on 17 meter SSB with Gene, AB9GK. 

This was the first DSB transceiver that I ever built.  I made this out in the Azores, probably in 2000 or 2001.  Years later I had replaced the RF power amplifier with a "JBOT" (Just a Bunch of Transistors) designed by Farhan.  

Over on my YouTube channel a comment came in from my friend Jack:  

@dhakajack

"Looking inside and seeing the o-scope probe in place while the radio was on the air reminded me of neurosurgery where the patient is awake and talking while the surgeon probes different brain regions soliciting feedback. Sure, ham radio isn't neurosurgery, but it's not too far at times. Also, you already have rocket science covered."

Here is an article about my build of that first rig:

https://www.gadgeteer.us/17METER.HTM

I think the article captures well the trials and tribulations faced by new homebrewers, perhaps with the twist that comes from being out in the middle of the Atlantic ocean.  

Mike WU2D is having similar fun with his homebrew 10 meter DSB transceiver: 

https://www.youtube.com/watch?v=uZt1LTGyoHc

I was struck by how similar Mike's early QSO experiences were with mine.  We both put our DSB transmitters on the air before they made their way into real cabinets or boxes. 

Here's mine from 2001 in the Azores: 

Innovation and a Dual Band Sweep with Version 2 of the 15-10 Transceiver

Here are a couple of videos on Version 2 of my 15-10 SSB transceiver.  In the video above I try to show the advances and innovations that have been made since the start of my BITX construction adventure back in 2013.  

 The video below shows the receiver in action this morning on 15 and 10 meter SSB.  I think it sounds pretty good. 

Click on the image for a better look

Farhan asked what the passband of the 25 MHz crystal filter looked like.  I sent him this.  I think it looks very good, and shows that it is possible to use an IF this high.  This permits us to not only set up the transceiver for dual band coverage (in this case 15 and 10 meters), but it also allows for a lower frequency VFO (in this case around 3.5 MHz) with a resulting increase in VFO stability.  

Dean's Amazing Homebrew sBITX

 

I was kind of making fun of  it during SolderSmoke podcast #250, but later that same morning I had a chance to watch the KK4DAS homebrew sBITX in action, in person, and I must say, it was very impressive.  This may be the only homebrew sBITX in the world (please correct me if I'm wrong).  

In the picture above you can see the amalgamation of traditional superhet with modern DSP.  Even for an HDR guy like me, the result is really cool.  Once again, I experienced waterfall envy.  And the sBITX receiver sounds great. 

Dean has written up his experiences with this rig in a blog post.  Check it out for more info: 

https://kk4das.blogspot.com/2024/02/homebrew-sbitx-receiver-gound-bounce.html

Thanks Dean! 

Pine Boards, Analog VFOs, and Homebrew BITX Transceivers -- AG5VG's Magnificent Creations

Click in image for a better view

This is amazingly cool.  WE ARE NOT ALONE!  There are others out there breaking the tyranny of the Si5351, building BITXs with analog LC VFOs.  And using copper clad boards affixed to pine boards. Plywood cabinetry!  And medicine bottle coil forms.  Really great.  And what a wonderful workshop. Thanks Michael.     

Good Afternoon Bill,

This is Michael Sahn, AG5VG.

I hope your doing well, all is well here in south Texas. I have recently built a bitx20 receiver and bitx20 for 40 meters receiver.

I built it using the analog VFO and both of mine are stable. What an awesome feeling it is to have a stable homebrew VFO. I have attached pictures .

It’s been a fun journey to get to this step. I have just been enjoying the receiver as Farhan instructed us. Then I’m going to go through the transmit side.

Air core coils are great for VFO. On my bitx40 I used a medicine bottle bottom but I put the VFO in a tin can as you will see in the pictures.

The bitx20 is all out, hand capacitance is a slight issue but it’s all learning experience.

Going to be adjusting the pvc coil bandpass filter inductors, I think the value is a bit off so it’s not as loud as it should be, but everything else is set good.

Just wanted to check in and great job on the videos and podcasts. I really enjoy them

73s

Michael

Click on image for a better view

Click on image for a better view

Scott KQ4AOP Successfully BUILDS a Receiver (Video) -- This is the Homebrew Spirit at its Maximum

This is just so cool.  Scott KQ4AOP has successfully homebrewed a ham radio receiver.  He used the circuit Dean and I developed (with a lot of input from Farhan and others) for the High School receiver project.  But Scott has had more success than any of our students.  And I think he has had -- in a certain sense -- more success than any of us.  After all, how many of us can say -- as Scott can -- that he used a homebrew receiver that he made to listen -- for the very first time -- to amateur radio signals?  Scott writes:  "Those first sounds were my first time ever hearing any Amateur Radio first hand!" 

In the email below, you can see Scott's deep commitment to homebrew: "I want to build my own gear for 40m. I want to learn morse code. I want my first contact to be on my own gear."  Wow Scott, the building of the receiver is the hard part, and you have already done that.  I think you are well on your way.  

In the video above you can watch Scott tune the entire 40 meter band and a bit beyond. You hear CW at the low end.  Then FT-8.  Then SSB.  Up just above the top of the band I think you can hear our old nemesis Radio Marti.  And this powerful broadcaster is NOT breaking through on the rest of the band.  FB Scott.  Congratulations.  

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

 Bill,

Thank you for the quick response, direction, and pointers. I won't give up, and I am not in a rush. 

I have wanted my amateur radio license since the early-to-mid-80s. I got my Technician and General in May of 2022 and completed my Extra in May 2023. I always wanted to understand how to design circuits, and I wanted to build them. I share that background to say that I have this impractical goal that I am stubborn enough to stick to (all due respect to you and Pete's advice on the topic of getting on the air). I want to build my own gear for 40m. I want to learn morse code. I want my first contact to be on my own gear. So, your blog and podcast really resonates with me. 

I am only teaching myself at this point. It was the perfect project for my goals. I thought that if all these high school kids in Virginia, Canada, and Germany can do it, it was the sweet spot I was looking for. 

The only transceiver I have was recently gifted to me. It is a Sommerkamp TS-788DX CB radio that allegedly works on 10m in addition to CB. I haven't connected it up because I wanted to stay focused on the HSR. I have a mentor who has gear that I can use to test the oscillator. I am not involved with the nearby ham club, but I know they would help if needed. 

Thanks again and I will keep you posted,

73 Scott KQ4AOP

KQ4AOPFebruary 2, 2024 at 10:49 PM

Bill and Dean - Thank you for sharing and documenting this receiver. I greatly appreciate you publishing the circuit, class notes, and build videos. That got me 75% to completion.
I feel blessed that both of you chipped in and encouraged me through the troubleshooting to finally getting the receiver to start “breathing RF”.
Those first sounds were my first time ever hearing any Amateur Radio first hand!

First Light! First Signals received on Version II of Homebrew 15-10 Transceiver

Ianis S51DX in Slovenia was the first call sign heard. Some peaking and tweaking remains to be done, but the receiver is working.

Congratulations to Scott KQ4AOP who got his Direct Conversion receiver working yesterday, And congratulations to Armand WA1UQO who got his regen receiver working. I think all of us are following Farhan's advice and are taking some time to just listen to the receivers we have built ourselves.

Check out the Hyderabad, India Hamfest! LARC-6

This all looks very familiar.  It is very much like the hamfests and rallies I've seen in the US and UK. 

Note in the video above that we see the HF Signals table and our good friend Farhan VU2ESE.

I was privileged to speak to the convention about my Mythbuster transceiver: 

https://soldersmoke.blogspot.com/2023/12/mythbuster-video-for-lamakaan-amateur.html

  

Joseph VU2JQE recorded and uploaded many short videos on the LARC-6 convention and hamfest.  You can see the on his YouTube page:  https://www.youtube.com/@VU2JQE  Thanks Joseph and thanks to the Lamakaan ARC. 

Mythbuster Video for the Lamakaan Amateur Radio Club of Hyderabad, India

I was really pleased when Farhan asked me to speak at this year's Lamakaan Amateur Radio Club convention.  He asked me to talk about my Mythbuster 75 and 20 meter SSB rig.  It was especially nice to talk about this rig because so much of the inspiration and circuitry for it came from Farhan's BITX rigs.  

I recorded a video so that we could avoid WiFi trouble -- the video appears above.  Below you can see photos of the convention and the presentation of the video.  

Thanks Farhan and thanks to the Lamakaan ARC! 

Sunburst and Luminary: Apollo "Rope" Memory, and other items of interest

 

Wow.  That is the method that they stored computer memory for the moon missions.  When they were satisfied with a program they would say it was time to "put it on the rope."  

Here's an article on the women who built the rope memory (and the integrated circuits used in Apollo). This reminded me of the women's collective in Hyderabad that "wove" the ferrite core transformers for Farhan's BITX rigs: 

https://www.sciencenews.org/article/core-memory-weavers-navajo-apollo-raytheon-computer-nasa#:~:text=Core%20memory%20used%20metal%20wires,to%20create%20a%20particular%20pattern.

Here is a Wikipedia article on core rope ROM memory with some great illustrations: 

https://en.wikipedia.org/wiki/Core_rope_memory

The Rope

Other stuff of interest that I have spotted so far in the book Sunburst and Luminary -- An Apollo Memoir by Don Eyles:  

-- Not long before the fatal Apollo 1 fire, an MIT colleague of Don Eyles had a drink with Astronaut Gus Grissom.  Grissom unloaded about the poor state of the spacecraft, saying that, "What we have here is a Heathkit."  Grissom died in the fire. 

-- Eyles mentions the use of 6L6 tubes in analog audio amplifiers. 

-- MIT's Doc Draper used a Minox camera.  

-- When the Apollo 11 astronauts came back and were living for two weeks in an isolation chamber, NASA had bulldozers on standby to bury the whole thing ("astronauts, staff and all") in case some dangerous moon bug was detected.  (Is that true?) 

-- At one point soon before an important missile test, engineers realized that they needed an isolation transformer.  They did not have enough time to order one.  So they took an isolation transformer out of one of their soldering stations and used it in the missile.  It worked. Sometimes you just use what you have on hand. 

SolderSmoke Podcast #247 -- Hating on the IC-7300, Pete Goes FT-8 with a KWM-1, Bill's 15-10 Rig, MAILBAG

Bill's 15-10 Rig -- Click on image 

SolderSmoke Podcast #247 is available: 

Audio Podcast:  http://soldersmoke.com/soldersmoke247.mp3

Video:  (482) SolderSmoke 247 -- Hating on the IC-7300, Pete goes FT8 (with a KWM-1), Bill's 15-10 rig, Mailbag - YouTube

Bill’s Bench:

The 15-10 Dual Bander.

n  10 pole crystal filter at 25 MHz.

n  G3UUR, Dishal, AADE and all that..

n  Testing woes.  Looked bad.  But it was a bad test cable. Duh.

n  VFO (Colpitts) at around 3.5 MHz.

n  Buffer blues:  Bad J-310s.  Beware!  

n  Variable cap from a Heath Q Multiplier

n  A bit of a black art – competing goals. Freq coverage, etc.

n  BFO needed an amp to turn on the diodes in the balanced modulator

n  TIA amps.   SIX dual direction TIAs.  18 transistors.

n  On a pine board (like Frank Jones)

n  Will use the N6QW all discrete AF amp.

n  Maybe an RD16 in the final?

n  Will build a second one for the DR.

 Shameless Commerce:  Mostly DIY RF and the PSSST kit.  Todd K7TFC reports:  “The P3ST is on track for Lee Deforest's birthday release (August 26th). I'm going to send out another newsletter on July 4th, and I'll give some details on P3ST development.” Results of Todd’s Survey.

Pete’s Bench

n  FT-8 on the KWM-1!

n  Presentation to the ham club.

n  Why the Icom 7300 is the anti-thesis of homebrew.

MMAILBAG:

-- SPRAT 195  Summer 2023, in the mailbox.  A happy day at N2CQR

-- Armand WA1UQO sent a wonderful book about Faraday and Maxwell… And told me Jim K8OI was heading to our area.  I met Jim at the VWS Field Day event.  FB.  Thanks Armand.

-- Tony G4WIF sent Father’s Day greetings.

-- Alvin N5VZH asking about electrolytics for his 2-B.  Hayseed Hamfest!

-- John AC2RL replacements for the IBEW.  We need to start over!

-- Steve “Snort Rosin” Smith WB6TNL was in the area.  Sorry I missed him.

-- Joh DL6ID helping us to track down origins of a homebrew receiver Grayson saw in Berlin.

-- Grayson KJ7UM was in Europe visiting his wife’s relatives.  But I think he is back in the USA.

-- Walter KA4KXX sent a QRP HB family portrait. 

-- Wouter ZS1KE sent info on surface mount soldering.

-- George Zaff KJ6VU Ham Radio Workbench – re-runs! Recommended audio processor.  Let me know how it sounds. 

-- Michael AA1TJ   Great to hear from him. 

-- Alan Wolke W2AEW on the toroids  he used in Diode Ring video.  Thanks Alan!

-- Dean KK4DAS, AI and SWR meter project  And new lexicon word:  Hamsplaining. 

-- Bob N7SUR --  Let me know we are semifinalists in the Hack-A-Day prize!  

The 15 - 10 rig from above -- Click on image