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Showing posts with label uBITX. Show all posts
Showing posts with label uBITX. Show all posts

Wednesday, May 17, 2023

Farhan Visits Northern Virginia En Route to FDIM (Videos to Follow)


Mike KD4MM, Farhan VU2ESE and Dean KK4DAS

Farhan VU2ESE was in Northern Virginia this week, on his way to the Four Days in May Event at the Dayton Hamvention.   We had a great visit with Farhan.  We took him out to the Thomas Jefferson High School for Science and Technology where he shared with the students tribal wisdom about building CubeSats and about building simple direct conversion receivers.  Farhan's use of direct conversion receivers to teach homebrewing to students in Hyderabad inspired our efforts in Northern Virginia.  We often referred to Farhan when speaking to the students here, so it was really great to give them a chance to talk to him directly. 


From the high school we went to the local restaurant at which Vienna Wireless has its weekly lunch. Many of the people at this lunch are also members of the VWS makers group.  This was a lot of fun. 


Don KM4UDX even brought in his somewhat eccentric build of the uBITX transceiver designed by Farhan.  Don's rig is labeled "The uBITX of Life."  It has also been called "The Franken-uBITX." Whatever the name, Farhan was clearly pleased to see Don's handiwork. 

I shot a lot of video during Farhan's visit (last time I failed to do this and regretted it).  I will put these videos up on the SolderSmoke YouTube channel during the days ahead. 

Thanks Farhan! 

Friday, May 5, 2023

SolderSmoke Podcast #246: PeteGPT! DC RX, Si5351, Franklin osc, Cuban DSB, Hex beams, uBITX mods, DX, 10 meters, MAILBAG

 

SolderSmoke Podcast #246 is available: 

AUDIO PODCAST: http://soldersmoke.com/soldersmoke246.mp3

YouTube VIDEO: (247) SolderSmoke Podcast #246: uBITX, Hex Beam, DX, High School DC RX, 10 meter SSB Rig, MAILBAG - YouTube

The AI Deep Fake Threat!  PeteGPT!

Hearing Aid info:  I can hear the cymbals in my audiogram adjusted Airpods.

Update on the TJ DC RX project – Several receivers working! https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

Sunil’s company provides Nano/Si5351 combos.  With the KD8CEC software. Very cool.  http://amateurradiokits.in They have a new SSB dual band transceiver – the Airpal.

Mark AJ6CU helping me. Sent me Nanos with KD8CEC software. His uBITX Settings Editor seems very cool. https://github.com/AJ6CU/uBITX-Settings-Editor/releases/tag/V2-beta-1  Thanks Mark.  

Franklin Oscillators. 

Cuban Islander and Jaguey info.  Send more!

Fixing up uBITX 2   How Bill blew up TWO Raduino Nanos. My results with the KB1GMX mods. (see below)

Hex Beam work:  Adding 10 and 15 meter elements.  But now I can hear AM breakthrough from WFAX 1220 AM  (5 kW during the day),  So I made a high pass filter.

Made first contacts on 15 and 10:  Argentina, Brazil, Dominican Republic.

First contacts with both India VU3TPW and China BA4TB.  SSB homebrew.

sBITX news. Taking orders!

Pete’s 10 Meter SSB Project

Mailbag:

--Wes W7ZOI provided great info and analysis on the Franklin oscillator. And lots of great tech info on other topics: http://w7zoi.net/oldtech/ponder.html Thanks Wes!
--Lex PH2LB. uBITX mods. TO-18 Heatsinks. New stickers (see above).
--Kostos SV3ORA and Hans G0UPL about the Franklin Oscillator.
--Listening to HRWB 178: Great stuff, many old friends: George KJ6VU moved to Oregon. Thomas K4SWL on the show.  Ben, an old friend of Pete’s,  mentions John Zaruba K2ZA – the guy who gave me the DX-100. Wonderful connections.
--Thanks to Todd VE7BPO for sending me another AADE LC meter. I need it for the SSSS.
--Nick MONTV planning a 15/10 meter dualband SSB rig. Me too! See video.
--Trevor Woods in W. Australia – The portrait in Artie Moore’s shack. Chuck WB9KZY – Willam Ramsay
--LA6NCA Helge three tube RX. Regen or DC? Mike Masterson WN2A and I discuss.
--Mike WU2D video on Retro QRP rigs – Steve G0FUW discusses Severn rig long in the works –started 1983 and nearly finished!
--Tim Hunkin of Secret Life fame did video with speaker made from potato ship bag. Discussed with Tony G4WIF and others. Also, Tim has an amazing video on cutting holes in metal. On the SolderSmoke blog.
--Bob Crane W8SX will be covering FDIM for SolderSmoke!
--Glen VE3DNL working on a more sophisticated DC RX.
--Craig KC2LFI from the beach on Grand Cayman. FB.
--Steve EI5DD reports We have changed our name - The May Issue of the HAM RADIO IRELAND Magazine, Ireland’s only independent magazine for the Radio Experimenter: https://docdro.id/SHH0VEy
--Mike EI0CL on 15 meters with Dean KK4DAS. FB
--Howard N3FEL of the Penn Wireless Association wants to do a group build of a DC RX.
--Martin LW9DTR in Buenos Aires looking for help with the code for an AD9850
--Todd K7TFC – always helping other homebrewers.
--Really thoughtful message from Kevin WN7Z

uBITX 2

My KB1GMX mods to uBITX 2

Saturday, April 1, 2023

SolderSmoke Podcast #245: Cuban DSB, DC Receiver?, Can you spot the AI? (Prize), Winterfest Loot, Gina's Podcast, 6BA6 buy, MAILBAG

 
DC RX Example by KK4DAS

SolderSmoke Podcast #245 is available for download: 


Video:  (68) SolderSmoke #245: Cuban DSB, DC Receiver?, AI, Winterfest Loot, Gina's Podcast, 6BA6 buy, MAILBAG - YouTube

Travelogue: Cuba DSB and AM. Jose CO6EC and the Islander. We need more info, especially on the solid state Jaguey rig.

Bill’s bench:

Will the High School DC receivers get finished? Future uncertain. But the project was technically interesting. Great working with Dean KK4DAS. Battling AM breakthrough from Radio Marti. We joked that Dean has been listening to Radio Marti so much that even though he doesn’t speak Spanish, he has noticed an increased urge to liberate Havana.

Audio amps: Harder than we thought. Lots of variation in Hfe of 2n3904s. Oscillations.
Not using feedback amps nor LM386s, nor push-pull. Simplicity is a design goal.

Fixing the tuning (bandspread) problem on the VFO was fun.

Antennas? A quarter wave with ground or counterpoise works well. We tried it. 
(59) An Antenna for the TJ 40 Direct Conversion Receiver - YouTube
----
Back to work on the uBITX. I chickened out on replacing the predriver with a BFR-106, but then – Just in time Todd K7TFC and his Mostly DIYRF came out with BFR106 boards! TRGHS. I will do the mods on two uBITX transceivers. I even bought a solder-sucking iron for the second job.

Winterfest Hamfest. Big success. Thanks VWS. HERRING AID FIVE! Simpson 260! QF-1, Another Radio Shack DMM, Eamon Skelton’s Homebrew Cookbook, Knobs, SWR meter.
----

SHAMELESS COMMERCE: 
-- Todd’s Mostly DIY RF and the BFR106 boards, and much more: https://mostlydiyrf.com/
-- Become a Patreon sponsor of SolderSmoke: https://www.patreon.com/join/4785634/checkout?ru=undefined

----
Pete's Bench: 

Technical Note: Skype problems. Pete's Skype kept dropping out. Bad in the last podcast (#244). Three minute gap. I was ready to scrap the whole podcast when Dean KK4DAS offered to help. And he is obviously well qualified: https://potomacofficersclub.com/speakers/dean-souleles/ Dean went to work with AI. And he was able to fill the audio and the video gaps. Can you spot the three minutes of AI? Send me an e-mail with the time segment of the AI/Deep Fake portion of SolderSmoke 244. The first one with the correct answer will win a prize. 
SolderSmoke #244:
Thanks Dean!

----Interview on his Pete's daughter’s podcast. https://soldersmoke.blogspot.com/2023/03/listen-to-pete-juliano-on-his-daughter.html

-- 6BA6 e-bay buy. Will we see an all 6BA6 rig from Pete?

-- The NCX-5 on e-bay

PETE’S NEW BLOG: https://hamradiogenius.blogspot.com/

Mailbag:

-- A New SPRAT arrived in the mail. PH2LB’s Gluestick on the cover.
-- Will KI4POV – Awesome homebrew – on the blog.
-- Sands, VK9WX listening to SolderSmoke on Willis Island! Wow. 
-- Andreas DL1AJG in Germany continues with the Electronics for Biologists DC RX build.
-- Dean KK4DAS and his homebrew 10 meter DSB rig.
-- Jim W2UO built a Michigan Mighty Mite and made a contact.
-- Dave K8WPE and the E in IBEW. We need new stickers.
-- Bob KC4LB – Surface Mount is SMALL.
-- Bruce KK0S on the Herring Aid 5 Board.
-- Chuck WB9KZY on Nuclear Monopole Resonance very cool video – on the blog.
-- Alan WA9IRS wants a CW editor for his phone. Really.
-- Vic WA4THR also working on uBITX power out improvement.
-- Tobias weighs in on Kludge. As in Fudge.
-- Tony G4WIF notes that when he changes his oil he often removes sludge, not slooge.
-- Consultations with Lexicographer Steve KB3SII.
-- Walt AJ6T says CW operating declined after FCC ruling in 1970s about callsigns.
-- Ramakrishnan VU3RDD now VU2JXN has joined the VWS. An old friend of SolderSmoke. Urged us to launch a blog back in 2008. We announced his daughter’s birth - - now Ram is getting ready to build a DC receiver with her.

Friday, February 10, 2023

SolderSmoke Podcast #243 -- HI7/N2CQR, uBITX mods for 10 meters, High-School Direct Conversion Receiver Project Launched (Success!) Mailbag

 
DC RX and one of the PTO boards we built as demos last night. 

February 10, 2023


SolderSmoke Podcast #224 is available. 


http://soldersmoke.com/soldersmoke243.mp3


Video here: (32) SolderSmoke Podcast 243 (video) Hi7/N2CQR, uBITX, Success with High School Receiver Project - YouTube


Pete N6QW had technical difficulties this morning.  He insisted that the show must go on.  Pete will be back for the next episode. 

 

Travelogue: 

Bill in the Dominican Republic for all of January.  

HI7/N2CQR  Eastern tip of the island. uBITX and dipoles. 

20, 17, 10.  CW and SSB.  SSB was tough and I had reports of RF getting into the signal.

Went to CW. 

Worked VWS Mike KA4CDN, and Walter KA4KXX on 20CW.

Finally moved up to 10 CW.  Lots of contacts. Even though uBITX very QRP on ten.

I am modifying the uBITX now.  

Copper tape shielding to keep RF out.

 Low power out not the fault of the IRF-510s.  The problem is the 2N3904s.

Will replace with 2N2222 in To-18 cans.

Dean KK4DAS putting KD8CEC software into Arduino.  I gave up.

Who sent me this orphan uBITX?

SolderSmoke Shack South in final phase of construction.

 

SHAMELESS COMMERCE DIVISION:

Patreon!

Bezos Shopping!

 

DC Receiver Project

Local High School radio club. 

Simple:  Like Herring Aid 5 and Wes’s original.

Farhan’s four stages:

BP Filter, Diode Ring, PTO, AF amp. 

Simple Colpitts PTO SURPRISINGLY STABLE.

Simple and easy.  No chips.  No complicated circuits.

Guys have helped test out the design:  Rick N3FJZ, Walter KA4KXX,

Daniel VE5DLD, Stephen VK2BLQ and others. 

First session last night:  We demonstrated build of the PTOs.  

They worked (thank God).

 

Open Circuits book.

Envelope Detection Controversy

Save the Antenna – Book “Losing the Nobel Prize” K1JT

 

MAILBAG

--Dean KK4DAS 10 meter DSB!  Tiny SA ULTRA! FB

--John AC2RL on Elmer W3PHL DSB guy

--AC3K reports inventor of Fender Stratocaster guitar was a ham: W6DOE

--AF8E was doing POTA.  I worked him. He said my rig had presence. FB

--Alain F4IET FB DSB rig with mic in Cigar can!

--Daryl N0DP worked him on SSB.  He is homebrewing

--Steve N8NM was in for repairs but is on the mend.

--Rick G6AKG working with sub-harmonic mixers and logic chips

--Paul HS0ZLQ Built DC receiver but looking for something else to build. No DSB!

--Steve AB4I – Coherer, Jagadish Chandra Bose, and Marconi

--Eldon KC5U    Worked VK5QD right after me and mentioned SolderSmoke FB

--Todd K7TFC is building the DC RX.

--Tony G4WIF and Ian G3ROO using automotive relays for antenna switching. FB.

--Dave WA1LBP Great to hear from my fellow Hambassador (Okinawa)

Older post comments:

--Scott VO1DR was also in CF Rockey’s class! (Blog comment)

--Aurora Aug 4, 1972: Twelve people shared memories.  (Blog comment)

--Will WN1SLG Googled novice call and was led to my Novice log.(Blog comment)


Sunday, January 15, 2023

Working Walter KA4KXX from Hispaniola

 Walter KA4KXX in Orlando has been a prolific builder of rigs for many years, and has been a great friend of SolderSmoke:  Here are some of the SolderSmoke podcasts and blog posts in which Walter's solder melting was mentioned: https://soldersmoke.blogspot.com/search?q=KA4KXX

As we approach the end of our current stay in the Dominican Republic, I could not miss out on the chance to work Walter with his homebrew rigs.  Even though the space weather was stormy, and my dipole was droopy, we arranged to meet up on the high end of the 20 meter CW band this morning.   See the results in the video above.  A solid QSO with Walter.  He says it is HB2HB, but truth be told I was on a uBITX that was built more by Farhan than by me.  But this was a great contact.  Walter started with a 50W rig, then switched to his 3 watt rig with a DC receiver.  FB

Here is the e-mail I received from Walter after the QSO: 

Dear Bill:

Many thanks for the great video, and when
you return to Virginia look for your mailman
to bring a postcard from me!
Just after your phone call this morning I scanned
the band from 14.025 to 14.300 and heard only one
SSB QSO at 14.347, and even now I only hear
a half dozen SSB signals, so that makes what
we did even more amazing. 
The first photo below is my 3.5 watt NE602 direct conversion 
rig which is about 2 years old.  The transmit signal is created
by putting a 3 MHz VFO signal into an NE602 mixer with an 
11 MHz crystal, so the rig can receive CW and SSB from 
14.025 to 14.300 and can transmit CW anywhere in that range
with good frequency stability. 
The bottom photo is my new full break-in CW 50W rig which 
I just put on the air about a week ago and is still in the finalization stage.  
I am not yet happy with it, but then again I am more particular
now than I used to be.  It is really a trans-receiver with a single 
conversion superhet receiver at the bottom of the board using 
an NE602 pair with a 3-crystal 4 MHz 900 Hz bandwidth filter, 
and a single 10.080 crystal VFO which is tuned with a polyvaricon
for operating between 14.061 and 14.068 MHz.  
At the top is the VXO transmit section using a pair of 14.070 
crystals pulled down into the operating range.  This signal
is buffered and amplified to about 500 mW which is all that 
the MRF101 RF Power Amplifier needs.  Visible behind the
board is an AC-powered 24 VDC switching power supply which 
is connected in series with the 12 VDC battery to 
power the final stage with about 36 VDC.  The main 12 VDC is 
provided by a bench power supply which is not in the photo.
In both rigs the morse code key is the microswitch 
at the lower right corner.  (Way more handy and elegant 
than your key, I might say?)
This morning each of these rigs was connected to its own
end fed half wave antenna, one in my backyard 
and the other on the side of my house.  My antenna analyzer
shows them to be essentially equal, but my 50W rig does
not like one of them at all.
Making our international homebrew-to-homebrew contact 
today was a terrific ham radio experience, so thanks for all 
you do!
73,
Walter 
KA4KXX
Orlando, FL

image.png

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Thursday, January 12, 2023

On Ten Meters with a uBITX from the Eastern Tip of Hispaniola


On ten from HI7.  Cluster spots, DX, CW, and the Reverse Beacon Network. 

 

Sunday, January 1, 2023

Happy New Year and Straight Key Night from HI7/N2CQR


HNY from HI7!  In keeping with SolderSmoke tradition, I recorded the above greeting.  If you look over my right shoulder, or in the picture below, you can see the apartment building we will be moving into (at least for the winter months) later this year.  There will be a small shack on the top level.  And yes, a telescope.  


This morning I fired up the uBITX on 20 CW and made two Straight Key Night contacts.  My key is the straightest of the straight --  a homewbrew thing made from an old hack-saw blade,  copper tape, brass screws, scrap wood, and duct tape.  Picture below.  


73 to all!  HNY and good luck in 2023!  

Saturday, December 18, 2021

On 17 meter CW from Santo Domingo with a uBITX



We are up on the 12th floor of a building in Santo Domingo. I brought my uBITX and managed to check in as baggage a 16-foot crappie fishing pole. I figured I needed to get the 1/2 wave antenna away from the building -- last time I was here I was unable to make any contacts from this location with the antenna stretched along the balcony. Last time I was QRP with an SST transceiver. 

The fishing pole worked well, but I operated with fear that it would fall or that the neighbors would complain). Today I got on 17 CW with the uBITX (more power than the SST), put it on 17 CW and promptly worked W4A, a special events station commemorating E. Howard Armstrong.  Turns out that today is Armstrong's birthday.  TRGHS.  

On the Reverse Beacon Network my CQs were heard by KO7SS in Arizona (very cool skimmer station at 8100 feet!) and by W2NAF (interesting operations in Antarctica, Svalbard and Virginia Tech). 



Tuesday, November 2, 2021

Farhan's Amazing Knack Story: From a Boyhood SW Receiver to the Design of the sBITX SDR


The presentation starts at about the 4 minute point. 

I think if I were only allowed to watch one YouTube video in the next year, I'd make it this one. 

In this amazing RSGB video, Ashhar Farhan VU2ESE takes us back to his earliest days as a radio amateur.  He tells us about his very early desire to build radios, his early projects, and his personal evolution as a designer and builder,  from a simple DC receiver, to the BITX, the Minima, the uBITX and now the hybrid HDR/SDR sBITX.  

There is a lot of  homebrew wisdom and tribal knowledge in this video. And we learn so many hitherto unknown details about the rigs that have become so important to us:  

-- Farhan had the EMRFD book with him on the famous flight from Sweden to India during which the BITX was designed. 

-- We learn about the origins of the BITX oscillator circuits, and that the VFO and BFO are essentially the same.  

-- I was really pleased that Farhan included a picture of my HB BITX17 rig in his presentation. 

-- Farhan discusses the difficulties he faced in obtaining needed parts in India. 

-- We actually see the nylon washers that Farhan used in the original BITX. 

-- Farhan discusses his early system for measuring coil inductance. 

-- In addition the huge contribution of EMRFD,  Farhan talks about how he was helped by Pat Hawker G3VA's writing, and the ARRL's SSB Handbook. 

-- Farhkan talks about his Tex 465 'scope and his building of a Spectrum Analyzer. 

-- We see his evolution to dual conversion. We see the conceptual birth of the Minima and the birth (thanks Wes!) of the TIA amps.  I didn't know about the HF-1.  Then Farhan designed the uBITX and now the sBITX.  

 -- Farhan talks about his practice of taking the pictures of new rigs with the new rig sitting atop the book that was most important in its design and construction.  FB. 

-- I was really blown away by Farhan's presentation of how the uBITX advertisement was inspired by and in many ways based on the Heathkit ad for an HW-101.  Amazing. 

-- I learned a lot from Farhan's discussion of SDR theory.  I pledge to spend more time with this.  I really like Farhan's hybrid HDR/SDR approach. 

-- But I have a question:  Farhan seems to say that we'd need a big expensive GOOGL computer to do the direct sampling HF SDR.  But doesn't the little RTL-SDR do just that?  Without a GOOGL?  

-- Great to see Wes's AFTIA being used in the sBITX.  

-- Really cool that Farhan has his mind on VHF transverters when designing the sBITX.   I liked use of the TCXO module to free up one of the Si5351 clock outputs.   FB.  And great to include an idea from Hans in this rig. 

Thanks very much to Farhan (who stayed up until 3 am to do this!) and to the RSGB for hosting.

Friday, May 28, 2021

Farhan's sBITX -- Combining SDR with the Traditional Superhet


Here is Farhan's amazing presentation to the virtual 2021 FDIM event.  There is a lot of tribal knowledge in this video.  Lots of old and new technology.  I was especially intrigued by Chris Trask's Kiss mixer.  Farhan's discussion of simple Arduino-based speech equalization and compression made me think that I have work to do in this area. And of course, Farhan's whole discussion of how to bring SDR into -- literally into -- the circuitry of a uBITX is really cool and very educational.   

Sunday, July 12, 2020

A Swedish Homebrew uBITX built in Dubai


It was great to get an update from Martin.  He has moved his workshop from Dubai back to Sweden.  We have seen lots of homebrew BITX monobanders, but very few homebrew multiband uBITXs.  Check out Martin's.  Very FB.   The input from Farhan was very cool, as was Martin's wise decision to follow Farhan's suggestion and to pause construction once the receiver was working.  As Martin put it, "I halted the build for a couple of days and just enjoyed listening."  Thanks for the update Martin. 


Dear Bill and Pete,

Here comes a long overdue update from my workbench, my last update was back in March 2017 when I had completed my first transceiver project.

I did not stop building and quite soon after I completed the CW transceiver Farhan posted the first schematics of the uBitx, why not? Why not get into a multiband CW-SSB transceiver as my next project.

After completing the receive part I was amazed... 


I halted the build for a couple of days and just enjoyed listening.
When it was time to start on the filters and the main RF Amp I sent Farhan an email asking about the way forward, he responded like this on May 17th 2017

"martin,
first, let me congratulate you, i suppose you are the first one to build a ubitx after me! second, i am not happy at all with the transmit line up, the drivers were not doing a good job above 14 mhz. i have replaced the 2n2219s with parallel 2n3904s. i also had to add two more LPFs, for proper harmonic suppression. i am headed for dayton today. once in dayton, i will try to find time to send you the latest circuit diagram. 
once again, congratulations on a wonderfully constructed ubitx."


Wow, what a shot in the arm for a fairly new home brewer!!! I was now back full speed with solder melting. I completed the filter bank and the RF amp, this is where I am starting to move away from the published diagram, I believe it is good to make it your own a little.

The end result was great, I worked many many stations in Europe and Asia with this little machine both SSB and CW.

In 2019 we decided to move back to Europe, the workbench and all boxes with parts and junk together with the rest of the household found their way into a 40ft container and was sent of to Sweden.

The A65DC Laboratories became SM0P Laboratories, the iron is still always hot and there is something brewing here all the time.

Thanks for a brilliant show boys,

Martin SM0P







Monday, June 1, 2020

Adam N0ZIB's FB Station (and UGLY Michigan Mighty Mite)


Bill and Pete, 

Thanks for the work you put into your podcast. I’ve been listening to it on my commute and while at work (I’m a welder/fabricator). Fantastic content.  Keep up the great work.  

All your talk about Farhan and the Ubitx convinced me to order one.  I welded an aluminum case for it and upgraded to the Nextion 3.5” screen. Also added a tuning knob from a Heathkit SB-401.  So far I’m really enjoying this rig. Plan to add an audio amp (to drive a larger speaker) and a CW filter to it this weekend.  In the station picture I sent I also show my paddles made from a hacksaw blade and stainless steel hardware. It’ll send 25 WPM before it gets a little sloppy.  My QCX 40 is also pictured.  I have a commercial rig too but find I’m not using it very often. 

Plan to start building the simpleceiver soon and maybe a bitx 17 too. Your podcast played a big part in convincing me to pick up a soldering iron again.  You guys are awesome.  Keep it up.  

73’s
Adam
N0ZIB



(Pete noticed that the main tuning knob on Adam's uBITX was NOT from Heathkit but was instead from a Collins KWM-2 or 32S3.  He advised Adam that the knob would sell quickly on e-bay.  It did, and will finance additional N0ZIB homebrew projects.  We are thinking of adding these knobs to our SolderSmoke Retirement Fund Portfolio.)   


Adam continues: 

I was listening to your older podcasts and heard several discussions about the Michigan Mighty Mite.  So this jumbled up mess probably doesn’t look like much but I built one. I need to order a 40 meter crystal and actually build it again on a board(with the coil rewound for 40) but my “proof of concept” build was a success. Using a variable cap from a Hallicrafters S20-R and the crystal holder from a Heathkit.  






Monday, February 24, 2020

SolderSmoke Podcast #218: S-38E Woes; CW filter for uBITX; A Teensy Explosion; Mint, Cheese and Peaberries; Mailbag; A SPECIAL PLEA FOR FEEDBACK


SolderSmoke Podcast #218 is available 



SolderSmoke 218 is Sponsored by AF4K Crystals
 Bry Carling can get you the crystals you need. 



Flying drones with Billy.  Amazing tech out there.  In the 50 buck range with video cameras and facial recognition and tracking.  Check out Air Pix. 

Bill's Bench: 

Active CW filter in uBITX. 
Hi-Per-Mite from 4 State QRP.  Easy to do. Works well. 
uBITX to 5 W level. 

S-38E adventure.  
Replaced antenna input coil BUT -- it came from an earlier S-38 and doesn't resonate. 
So I bought a junker on e-bay and will take the E model coil out of that one. 
Had to re-string the dial!  And add rosin to it from Maria's old violin. 
BFO was not working.  Bad buzz sound. 
So:  Re-cap, Re-tube, Re-string, Re-align, Re-build power supply.  
Shortwave sounds good.  Nice to hear music coming from our machines.  
SHAMELESS COMMERCE DIVISION:   Please use the Amazon Search Box in the upper right hand portion of the blog.

Pete's Bench

A teensy-weensie explosion and fire
Mint!  Kl7FLR
60 Meters
Cheese    Microscopes
Peaberry
Radig
California hams using online SDR receivers for local nets.  

News You Can Use!
J-310s in LTSpice


MAILBAG

K5HCT August via Regen and YouTube

Doug WB5TKI and his wife read "Us and Them."

Rich K7SZ finally following SolderSmoke Podcast.  Welcome aboard Rich. 

Rick KD4KRA  His son was one of the kids in the MIR-Classroom contact that I monitored around 1993...

David AD8Y  Read SolderSmoke Book.  Similar Knack story.  Shared 1978 story:  Homework net on 75 meters.  

Paul KL7FLR Tapping and other tribal knowledge. 

Dave K8WPE   Says I'm fortunate to have a supportive wife.  So true. 

SPECIAL REQUEST:   IT IS VERY DIFFICULT FOR US TO KNOW HOW MANY PEOPLE ARE LISTENING TO THIS.  SO PLEASE, SEND AN E-MAIL TO SOLDERSMOKE@YAHOO.COM   JUST SAY THAT YOU LISTENED TO PODCAST #218 AND TELL US HOW YOU LISTENED TO IT (ITUNES, DOWNLAD FROM BLOG, STITCHER, PODBEAN, WHATEVER...  THANKS





Friday, February 21, 2020

PH2LB's Homebrew Hi-Per-Mite CW Filter in his uBITX



I really like the way Lex PH2LB measures and demonstrates the effectiveness of the Hi-Per-Mite CW filter designed by David Cripes NM0S.   Watch the short video above.  The blue trace is the audio input to the filter, the orange trace is the output.  Watch the output change as Lex sweeps the audio frequency range. 

He wrote: 

After studying the schematic I shifting through my spare parts stock to collected the components and build one according there design on a breadboard (I changed the center frequency from 700 to 600Hz).
I hooked up my signal generator with a amplitude of 2v max and sweeped it from 250Hz to 2KHz looking at the output on my rigol osciloscoop. On 2khz VMAX=0.04V, 885Hz=0.2V, 700Hz=1.5V, 662-585Hz=2V, 400Hz=0.2V, 500Hz=0.9V, 250Hz=0.04V. So a nice flat top between 585Hz to 662Hz.

A full description of Lex's project (with more videos) is here: 

https://www.ph2lb.nl/blog/index.php?page=ubitx-mods3#ubitx-mod14

Lex's Knack Story and the intro to his blog is here: https://www.ph2lb.nl/blog/index.php?page=history

Wednesday, February 19, 2020

Hi-Per-Mite Active Audio CW Filter Installed in uBITX (video)



Coming home from the Dominican Republic, this was a major item on my list of desired mods for the uBITX: a narrower passband for CW.  Using the 2.3 kHz SSB passband, you could have many CW QSOs audible in your headphones.  Narrow that passband to 200-300 Hz and life gets a lot easier. 

Farhan had discussed adding a 12 Mhz IF filter of suitable CW bandwidth, but this seemed difficult to me. Besides, I have long wanted to use an active audio filter for this purpose. 

The Hi-Per-Mite filter from 4 State QRP Group is just what I needed. I built the kit without problems in about an hour, then I put it in the uBITX box, with  switch on the front panel that lets me put it in the circuit or take it out -- this is very satisfying and a lot of fun.  

The Hi-Per-Mite just goes between the uBITX audio out and the speaker/headphone connection. I built mine for "no gain" -- the uBITX provides plenty of audio. 

The selectivity with the Hi-Per-Mite compares favorably to that of my Drake 2-B with the 500 Hz LC filter.  You can get an idea of the performance in the video. 

Three cheers for the 4 State QRP Group and their Hi-Per-Mite!  Here is the page with all the info: 

http://www.4sqrp.com/hipermite.php


Thursday, January 30, 2020

Mountain Topping in Indonesia -- Very Cool Video



OM Kenji has an awesome video about a mountain topping trip that took place in Indonesia just yesterday.  Very nice.  

I like the use of the neodymium magnets to attach the paddles to the rig.  I may try that with my homebrew straight key and the Samana-uBITX. Or I may have to get a keyer and learn (finally!) to use paddles.  (But simplicity is a virtue and there is nothing more simple than a straight key.) 

Kenji is obviously an amazing cook, even in the field.  I like the coffee-making technique. 

Check out more of his videos (and subscribe) at his YouTube Channel page: 

https://www.youtube.com/channel/UCpfn1viFoqVmWk6x891nKaQ   

Thanks Kenji! 



Wednesday, January 15, 2020

Notes From the Dominican Republic on possible uBITX mods


It was really great to have the multiband and CW/SSB capabilities of the uBITX with me in the Dominican Republic.  And even with my large wooden box, the rig and all its accouterments fit into my carry on baggage (and there were no problems with airport security). (In the picture above you can see the cloth case that held the whole station, including the antenna.)  

As I used the rig, I thought about possible mods for future operations.   Here are some ideas: 

-- Filter for CW?  Definitely.  Farhan suggested switching in a more narrow 12 MHz IF filter for CW operations, but that seems like a bit too much work.  I am going to try to use an audio frequency filter.  I've ordered the active CW filter from QRPguys.  I've long been intrigued by these kinds of filters, but they didn't seem very wirthwhile with a DC receiver.  With a superhet like the uBITX they make a whole lot more sense. 

-- Sidetone volume control.   Need it, especially with fellow vacationers trying to sleep nearby.  Should be easy -- just a pot on the side-tone line.

-- Low impedance mono headphones.  Need them.  

-- An LED light for logging.  Would help. 

-- Switch to turn off the 16X2 display to save power?  I thought about this but I checked after we got back and the whole display pulls only about 20 ma.   So it probably isn't worth it to put in a switch. 

-- Internal protective cover for the uBITX board.    I used the extra space in my big wooden box to store the key, the mic, the battery, the tuner, etc.    They all bounce around a bit and could damage the uBITX board.  So I will try to build in some internal physical shielding, perhaps from a BITX plastic box. 

-- Brass contacts for my homebrew CW key.   I think brass is better than the copper foil I am currently using.  I already did this with some brass bolts from the local hardware store.  Mush improved.  Pounding brass is better than pounding copper tape. 

-- I installed an additional stage of microphone amplification but I have this stage running even on receive.  But I checked and the amount of current pulled by this stag is so small that it is not even worth changing the power supply line. 

--  Reduce output to below 5 watts on CW.   To make the rig "QRP Compliant."  



In the pictures you can also see my homebrew straight key, the QRPguys EFHW tuner, my mic (the original SolderSmoke podcast mic!), the 3 amp-hour LiPo battery, the additional stage of mic amplification.   The little relay that you see just above the mic amp allows for the keying of an external amplifier. 



Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column