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Showing posts with label sBITX. Show all posts
Showing posts with label sBITX. Show all posts

Wednesday, October 16, 2024

SolderSmoke Podcast #253 AUDIO VERSION: NYC, SF, DR, PC, DSC, PODCAST IN DANGER, SPRAT, sBITX, CW, IMD, AI, PNP, MAILBAG


SolderSmoke Podcast #253 is available:  

 http://soldersmoke.com/soldersmoke253.mp3

October 16, 2024

Sponsor!  Parts Candy is back!  Handmade in Chicago!  Standard test leads,  Hook clips, alligator clips in 12" and 32" and multimeter leads

Travelouge/Intro

Bill's trip to NYC -- The Empire State Building

Dean goes to the Bay area. 

Harry Caul,  Marty Klein W3VCG , "The Conversation" and THE KNACK.https://soldersmoke.blogspot.com/2024/08/harry-caul-had-knack-movie-review.html

Joe Piscopo in Bell System video! https://soldersmoke.blogspot.com/2024/08/soldersmoke-quiz-question-who-is-actor.html

Bill's Bench 

Bill's report from SolderSmoke Shack South: The tropics:  What this means.  Guapo wouldn't  go out when the sun was overhead. 

 Skies not great for astronomy now.  But we see a lot of satellites, and meteors.

Antenna developments:   1/4 vertical on a fishing pole.  

Lightning suppression coming for the building. Lightning suppressors.  Got 2.  Good video from the IMSAI guy: https://www.youtube.com/watch?v=7EyABPuNDMA Argon gas suppresion tubes.Need to crimp! 

Hurricane prevention. Metal storm curtains. 

Thinking of solar panels. 12 panels, 5 kW system.  Probably without batteries.  What do you think? 

A golf cart. 

New PC.  BeeLink.  Very tiny! (palm of your hand)   24 inch screen. Works well https://www.amazon.com/dp/B0BVFKN7ZL?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

A very satisfying fix on the 15/10 rig -- loose connection to RF amp.  The highly suspect Ramsey Kit Amp was NOT the culprit!  Got to use the new Rigol DS-1102.  A fun fix. Will build a second CCI amp. 

Digital Selective Calling -- listening to ships and shore stations on HF.  https://soldersmoke.blogspot.com/2024/10/monitoring-maritime-radio-messages-with.html

SHAMELESS COMMERCE:  Our blogs and the podcast are in danger!  Pete is already on a permanent  blog hiatus.  I have seen a big decline in readership.  Frankly, if no one is reading or listening, we just may decide not to do it anymore.  We don't want to do this.  So please, link to the blogs.  Talk up the blog and podcast on your own blogs and social media.  

Parts Candy Test Leads are back as our sponsor.  Pete has them.  Dean has them, I have them in two different countries!     DON'T SCRIMP WITH A CRIMP!  

SPRAT Summer 2O24 Special EXTRA 50th Anniversary issue! https://www.gqrp.com/sales.htm

Dean's Bench

First CW contact:  With KK4DAS on his HB sBITX  and  Alan W2AEW POTA.  TRGHS. 

Dean fixes the sBITX problems. Again.  SUB-THRESHOLD CONDUCTION!    Lots of patience and stick-to-it-ivness. LPF leakage!  https://kk4das.blogspot.com/2024/08/homebrew-sbitx-lpf-leak-stopped.html

IMD IMD IMD and the Tiny SA Ultra https://soldersmoke.blogspot.com/2024/09/sherwood-its-time-to-clean-up-our.html

AI  AI   AI -- Experimental AI Podcasts about SolderSmoke (no kidding -- (NOT April 1) Where they came from https://soldersmoke.blogspot.com/2024/09/where-ai-podcasts-came-from.html 

AI Podcast #2 https://soldersmoke.blogspot.com/2024/09/here-is-another-short-podcast-about.html

AI Podcast #1  https://soldersmoke.blogspot.com/2024/09/a-new-experimental-podcast-about.html

Pete's Bench

 An all PNP rig -- A notional look, https://n6qw.blogspot.com/2024/08/august-30-2024-pnp-20m-ssb-transceiver.html 

Videos on old Boatanchors. https://www.youtube.com/watch?v=mnboJ75NCmY&t=1s

MAILBAG:  

Lex PH2LB making some new stickers.  Look out San Francisco!  

Rogier PA1ZZ sending lots of good ideas and links. 

Todd K7TFC  great idea on SS readersip decline 

Todd VE7BPO  aka Vasily -- great info on how to stabilize LC oscillators. https://soldersmoke.blogspot.com/2024/09/qrp-homebuilder-shows-us-how-to-build.html

Eric 4Z1UG  Welcome words of encouragement on the blog and podcast 

Dave W2DAB says that AI just can't replace the Tappit Brothers of ham radio.  Now the Tappit Triplets. 

Michael AA1TJ  Thoughtfully skeptical about AI. 

Grayson K7JUM on the cleanliness of the 32S-3. Also amazing video on Thermatron MMM. 

Mike WN2A working on DC receivers and hum! 

Floran OE7FTI building Farhan's JBOT amp! 

Mike Murphy WU2D building 1930 replica rigs using a Frank Jones circuit 

Dave K8WPE always great to hear from such a strong SolderSmoke supporter. 

Walter KA4KXX  Great ideas from the Wizard of Orlando. 

Paul G0OER -- Reacting to the 1970s Ham Radio video. Didn't remember being so cool. 

Thomas K4SWL -- Struggling with the hurricane in NC.  Hang in there OM. 

Nick M0NTZ building another Direct Conversion receiver -- with videos about it.

Michael AG5VG building a Mythbustrer-style 20 meter rig.  FT-101 VFO.  FB

Tony G4WIF -- Readership problem advice 

John AB2XT sent us 6000 47 pf NP0 capacitors.  So we are now good for caps!   Thanks John. 

Paul VK3HN Was suitably impresses by the AI podcasts we put on the blog. Thanks Paul. 



SolderSmoke Podcast #253 VIDEO VERSION : NYC, SF, DR, PC, DSC, PODCAST IN DANGER, SPRAT, sBITX, CW, IMD, AI, PNP, MAILBAG

SolderSmoke #253 is available in video form.  See above or: 

https://www.youtube.com/watch?v=DQBojTLL7VY

The audio version is available in the post immediately above this one, here: 

https://soldersmoke.blogspot.com/2024/10/soldersmoke-podcast-253-audio-version.html


Tuesday, June 25, 2024

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.

Saturday, June 1, 2024

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


Monday, April 1, 2024

SolderSmoke Podcast #251 Aurora! CBLA, Winterfest, Legal Action Against SolderSmoke, HB sBITX, SDR, Raspberry Pi, Rounded Passbands, MAILBAG

Aurora Picture by Dean KK4DAS

SolderSmoke Podcast #251  4-1-2024

Audio: http://soldersmoke.com/soldersmoke251.mp3

Videos: Podcast 251 Aurora! CBLA, Winterfest, Legal Threat, sBITX, SDR, RaspPi, Rounded Passbands, MAILBAG (youtube.com)

Travelouge:  Dean goes to the North Pole to see Aurora. 

A CBLA Call to Arms! 

Winterfest.  Lots of goodies.  MXM Industries 40 meter transceiver. 1 dollar. 

Jean Shepherd. Recording of Bill talking to Shep in 1976. 
 https://soldersmoke.blogspot.com/2024/03/listen-to-me-talking-to-jean-shepherd.html

Legal Trouble: Could put us out of operation for a while.  We need listener input. 

November 2023

December 2023

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Pete's Bench

Homebrew SDR (based on Zl2CTM’s original design) and how good it sounds.

Raspberry Pi Zero W is now working on FT-8 with digital adapter.

Ferrite Cores at Digi-Key (a replacement for the FT-37-43 where  you buy 100 and the price is 21 cents/each)

ADE-6 –great specs in HF but more expensive than the ADE-1

For Pete's recent blog posts, go to this site and click on "Archive" in the right column: 

https://n6qw.blogspot.com/2024/03/march-31-2924-happy-easter-to-those-who.html

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Dean's Bench 

sBITX progress, McGyver-ing a lifted pad, replacing crystal on the CODEC board, sBITX success! See: 

https://kk4das.blogspot.com/2024/03/homebrew-sbitx-tx-modules-pa-lpf-and-mic.html

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Shameless Commerce Division:  Please use the Amazon link on the blog to start your Amazon purchases. And please consider using Patreon to support the podcast and blog.  We try to send extra content to our Patreon supporters. Mostly DIY RF --  Boards, Kits and Pete's PSSST

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Bill's Bench

More trouble with the 15-10 rig.  Rounded passbands in 25 MHz filter. See figure 4 in both links: 

https://www.arrl.org/files/file/QEX_Next_Issue/Nov-Dec_2009/QEX_Nov-Dec_09_Feature.pdf

https://www.networksciences.com/pdfs/tutorial.pdf

Experimenting with Balanced Mixers and Product Detectors. Paul VK3HN  Suggests the MC1496 chip; Walter KA4KXX points to SSDRA circuits

But it is on the air!  Using the PA from a BITX40 module and an RD06.  

Put an OLD dial from Pericles HI8P on 15-10 version 1.  Soul in the new machine.

Pericles' Dial on the 15-10 Rig 

Mailbag: 

Grayson KJ7UM's Hollowstate video. 

Mike WU2D's amazing 10 meter DSB transceiver. 

Jack AI4SV (Dhaka Jack) liked video of recent QSO with AzoresDSB rig

Mike AA1TJ and Dave AA7EE on backwaves and 100 uW QRPpppp

Dave G3UUR  on my curved passband problem

Alan W2AEW heard my only QSO with the MXM indsutries SupeRX/TX40

Wes W7ZOI, Mike WN2A, Walter KA4KXX. Farhan VU2ESE on passband, 

Ramakrishnan sent article about Charles Proteus Steinmetz.  Beautiful. 

Justin AC8LV built a receiver!  FB. 

San Francisco QRP:   KDOFNR TouCans Rig, and N6ASD Zinc-Oxide TX

Frank KC8JJL -- Another guy who heard first ham sigs from a homebrew rig. 

Nate KA1MUQ's homebrew thermatron superhet

Dino KL0S sent info on the PAL CB VFO I picked up at Winterfest. Airborne! 

Bob W8SX will be once again doing SolderSmoke interviews at Dayton.  Thanks Bob

Peter VK2EMU  Always good to hear from him.

Tobias Feltus -- Wisdom teeth removed, wondering if he will get sBITX hallucinations...

Rick WD5L continues to work on his Herring Aid 5

Ciprian YO6DXE wants to learn CW. No alerts from his FB Blog!

Todd K7TFC -- Likes CW, says it eliminates the Blah-Blah-Blah 

F1BFU's Amazing PSSST VFO

Monday, February 12, 2024

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: 


Thanks Dean! 



Saturday, February 10, 2024

SolderSmoke Podcast #250 Dean KK4DAS joins Pete N6QW and Bill N2CQR


SolderSmoke Podcast # 250 is ready for download: 

http://soldersmoke.com/soldersmoke250.mp3

VIDEO VERSION: (1707) SolderSmoke Podcast #250 -- With Pete N6QW, Dean KK4DAS, and Bill N2CQR - YouTube

Intro:   Welcome to Dean KK4DAS.  For 2024 Pete and I hope to jazz things up a bit by bringing in fellow homebrewers to talk about their projects.  Dean is our first victim.  Welcome Dean. 

Some good news:  Several new homebrew receivers are inhaling:  Armand WA1UQO in Richmond has an amazing looking regen.  Scott KQ4AOP in Tennessee got his DC RX working.  Mike AG5VG in Texas has been homebrewing BITX 20s and BITX 40s.  All are on the blog.  

Pete's report: 

-- Recent blog entries on filters,  SSB rig architecture, and of course digital VFOs. 

-- Phasing measurements, quadrature, and the Seeed Xiao RP2040

-- Error in QST article on early SSB transceiver.  ANOTHER ERROR!

--LC VFO on blog!  FB Pete!  

Dean's report:  

-- Tales of woe on the homebrew sBITX

-- Help from Farhan.  

-- Ground Bounce.  FFT Hallucinations.   Wisdom files.

SHAMELESS COMMERCE DIVISION:   

-- Whenever you are tempted to buy something from AMAZON, just start at the Amazon symbol on the right side of the page.  We get a cut from Bezos, and it doesn't cost you anything.  

-- You can try to do the same thing with E-bay.  We are finding a lot of great parts there. 

-- If you see a SolderSmoke post on Facebook,  please Like and forward. 

-- Become a patron!  Go to the Patreon page.  We put the money to good SolderSmoke use. 

-- Visit Mostly DIY RF and buy a PSSST kit!  

Bill's bench:  

-- Building yet another BITX dual bander.  15-10 again. Tried to use a 25 MHz filter left over from the earlier project, but I had to build another.  Built a new VFO using the variable cap and anti-backlash gear recommended by Pete.  Was a bit tough to get the receiver sounding good.   Had a diode ring as the second mixer, but went back to a singly balanced mixer. 

-- 10 meter AM -- Thanks to Jerry Coffman K5JC for mod. 

Other topics: 

--Counterfeit chips.  Why? 

MAILBAG: 

Wes W7ZOI 

Jim Cook W8NSA  Transoceanic BFO

Grayson KJ7UM -- Vintage Computer Museum

Chuck Adams --Glad to hear that Chuck is doing well.  

Frank Harris  K0IYE --  NO CHIPS!!!! 

ED DD5LP  Antenna software

Eldon KC5U  10 AM We  made a contact

Joh DL6ID  10 AM   

Phil   W1PJE of MIT   10AM   Where is L5? 

Bob WP4BQV now in UK 

Dino Papas KL0S in Wilmington   Reverse Polarity protection. 

AA7EE Dave Richards  Liked Armand's receiver

Rogier PA1ZZ  

Jonathan-san W0XO  Listened to my ET-2 CW Whoop,whoop

Nick M0NTV  Great videos from Nick the Vic

Will KI4POV  Working on his own SSB rigs.  

John West -- Who is the South American ham who made his capacitors and heat sinks? 

Ed KC8SBV  Working on DC receiver, experimenting with FETs 

Mike WN2A great contributions.  Si5351 sole source danger! 

Nick N3FJZ -- watch out for dead bands when testing receivers! 

Don KM4UDX encouragement from new Prez of VWS

Dave K8WPE Likes QF1 Cap backlash.  Says I'm getting soft! 

Dave WA1LBP My fellow Hambassador, from Okinawa USMC Sergeant with a workshop. 

Friday, December 15, 2023

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: 
  
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. 


Wednesday, May 31, 2023

Farhan VU2ESE FDIM Interview (#6) by Bob Crane W8SX: VHF Rig, sBITX, and Good News on Raspberry Pi 4

It was great that Bob was able to catch up with Farhan and talk to him about his VHF rig and about the sBITX. 
    
Farhan said that the VHF rig (the BITX23) was presented at the homebrew show-and-tell as a project.  The idea was to encourage others to get into VHF homebrewing.  Farhan points out that many of us are reluctant to go into VHF building, thinking that we need special or exotic test gear. No true says Farhan.   He is trying, with this rig, to bust this myth.  FB.
    
On the sBITX, Farhan points out that he too -- coming as he does from the homebrew tradition -- finds some of the modern rigs quite intimidating.  So he designed the sBITX to be less intimidating.  It is, he says, a tinkerable rig that could be homebrewed. It is all open source.  
    
Farhan points out that the rig is built around the Raspberry Pi 4, a device that has recently been hard to obtain.  This has driven up the price of the sBITX a bit.   But good news:  Farhan says that the word on the street is that the Raspberry Pi 4 will be available in quantity starting at the end of June.  

Here us Bob's interview with Farhan: 

http://soldersmoke.com/VU2ESE23.mp3

BITX23 VHF Rig

And here is a video of Farhan describing the BITX23: 

Thanks Fathan!  Thanks Bob! 

Saturday, May 20, 2023

Farhan and Bill Fire up the sBITX and (at the other end of the tech spectrum) a Direct Conversion Receiver (video)


At the high tech end: the sBITX.  At the low tech end: The high-school direct conversion receiver. 
Check out the frequency readout on the DC receiver!  
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column