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Thursday, December 12, 2019

VU3JVX's Beautiful Homebrew Scratch-built uBITX (Builder looking for work -- See end of blog post)

When Farhan announced that BITX40 Module boards would no longer be produced,  my first thought was that it is, of course, still possible to homebrew a BITX.  Anthony VU3JVX proves that in his wonderful description of his uBITX scratch-built homebrew project.  Anthony obviously learned a lot  -- perhaps the most important lesson for new homebrewers is what Anthony did when he couldn't get the receiver to work: HE TOOK A BREAK and went back after a few days.  That is very important. 

I also liked very much the fact that Anthony did what Farhan did when the receiver came to life -- he stopped building the transmitter and just listened to the receiver that he had built. FB OM.  

And three cheers for Anthony's XYL -- she was very wise to suggest that he take on a project like this when he found himself out of work.  

Anthony VU3JVX wrote: 

I would like to share my journey of building ubitx from scratch, I would also like to dedicate this to Farhan (hope he will read this sometime) as he has always motivated to homebrew stuff.

I got my license 'VU3JVX' on March 2017. Passing the exam and getting on HF bands is still two different things. Yes, I started to transmit to local VHF repeater with cheap Chinese Bafong radio, I believe the most economical way to start the ham operator experience. However, I knew that I am missing something since I was not able to operate on HF bands.Coincidentally I saw that bitx40 became available as kit from HF Signals during the same time. I was happy to try it and that's how I made my first HF rig. Then I came to know about the BITX20 forum and joined the same, one of the best thing I did after buying bitx40. I have learned a lot from all the great people caring and sharing information. I will try to contribute whatever way possible from my side in coming days.

I was already thinking of building bitx40 for other band (because the way Farhan Sir has drawn the schematic it becomes so tempting for DIY) and then ubitx happened and it changed everything. I started studying the ubitx circuit and collecting all the required components, even ordered the exact toroid from W8DIZ website (during my good days and travel to US) but I was not having enough time to put things together on the bench as I am by profession a computer network & security engineer. However, I lost my job this year on month of July.  (ANTHONY IS LOOKING FOR WORK -- SCROLL DOWN IN THIS MESSAGE FOR DETAILS).  After this I was not sure what to do next, during this time my XYL suggested me that why don't I focus on something which I always wanted to do but never got enough time and that's how my journey started to build the ubitx from scratch.

Honestly, I was not sure if this was the right time to start this project. So I started to work on building the receiver segment of ubitx only. I had my challenges during this time and at one point I thought I made a wrong choice of building ubitx, instead I should had tried the bitx40 circuit first. I was almost on the verge to pack up and shelf the project because I was not able to hear anything from the receiver itself forget about building the transmitter. Then took a break for few days and then started troubleshooting each segment one by one. Finally I found it after reading through the bitx20 forum that my Q70 to be defective then I also came to know that is it better to replace it with audio type transistor 2sc945.
I believe during this process I have read most of the content on bitx20 forum. Some name which repeatedly comes to my mind are Raj (vu2zap), Allison, Jerry and thanks to all other hams out there. I had all the version schematics but started my work based on V5 and wanted to get the best out of all the version so I kept the build approach modular and laying them almost like the schematic for easy troubleshooting (you can see those pic on my qrz page).

Next challenge was trying to be too good student and follow everything the master said (pun intended). I made a cocktail of 12 Mhz with 11.059 Mhz crystal filter (Farhan Sir I believe the schematic is still showing X7 as 12 Mhz) and after changing the X7 to 11.059 Mhz I was able to see the radio signal making it through the crystal filter, then came the next hurdle of fine tuning the USB and LSB and fiddling with the software for the right value. After the receiver started working I took a break from building the radio and started enjoying the receiver and checking all bands. One evening I narrowly missed Farhan ji on air but anyway I would not have been able to communicate with him since my ubitx transmitter was not ready.
After that day I thought of building the ubitx transmitter soon. I was quiet confident about the transmitter build by this time and thought it should be straight forward. Logically yes it should had been that way but I was so wrong. Following all the recommendation from the forum about harmonic issue and how to avoid them I started building the BPF. Then I started to work on the PA section then came tuning the IRF510 current (I call it "Bell the cat moment") luckily I never blew any IRF510. However, the output watt on 40 M was hardly 2-3 Watts and other higher band less than 1 Watt. I knew something was wrong with those MOSFET but out of circuit the test look normal. I had some other stock from different source even those performed the same. Played around with different PA transformer settings and checking/tracing the RF signal. Everything looked normal till IRF510. Chances of fake IRF510 is less (as debated on the forum) as it is not an expensive RF part like RD16HHF1. Now I was confused, I had some spare new RD16HHF1 which I got online, which I was not very hopeful thinking that it might be fake. I thought of giving it a try (pin layout configuration was easy for me as I have taken the island cutting approach on single side copper board).

Voila ! I got a whopping 10+ Watt 40M, 5W on 20, 10W on 17M, 10W on 15M, 5W on 12M and 10M. Yes there are lot of fake IRF510 out there. Now it was time to test the homebrew rig on air, checked in at evening into All India Net and got 59 report and the net controller thought I am using commercial rig. Finally during these difficult time in my personal life I was able to smile and sleep well that day. The icing on the cake was installing the Nextion 3.5 display (If I remember correctly this is single most expensive component in the radio and thankfully it is optional).

Does that mean everything is 100% with my home brew ubitx ? Nope, I am still trying to figure out the feedback issue from the speaker during transmit. I traced the issue and found the audio leaking from emitter of Q6. I would like to mention that I tried all the audio circuit and finally settle for TDA2822 circuit. However, the issue is still there during transmit so I have made the audio circuit offline during transmit, I know this will impact my CW listening while transmitting when I upgrade my license . I have exhausted all solutions from Bitx20 forum but still no luck. I would be happy is someone can point me to the right direction. I would be also happy to share any information related to my build or the software settings/tuning, yes I like programming especially 'C' so I am comfortable with Arduino programs. I am thinking of building another PA module with IRF510, I personally feel IRF510 (I got the original finally) has made the home brewing so interesting. 

Anthony VU3JVX
Anthony is looking for work. Perhaps someone in the SolderSmoke community might be able to provide him with a lead.  Anthony writes:  

"I am a seasoned Enterprise and Banking Network Services professional with experience in project management and project execution.

Experience in IT Network and Banking services. I have experience in different technologies including WAN operations, Routing /Switching, MPLS, Multicast, Wi-Fi, Remote access, VPN, Network Security, Windows / Linux systems administration, troubleshooting, designed, installed, configured and maintained complex routed LAN/WAN and SDWAN networks."

I am also Cisco certified."  

Contact Anthony at: 

NOAA Prediction for Solar Cycle 25

A peak sunspot number of 115 might seem paltry, until you remember that we are at ZERO now.

Wednesday, December 11, 2019

Antuino Filter Analysis

Farhan had given me one of the early Dayton Hamvention models of the Antuino SWR/PWR/SNA RF test lab.  He later identified the need for a few mods to improve performance on that early model.  So I brushed up on my surface mount soldering, got the needed (tiny!) parts and made the mods.  I also put the battery pack inside the box and put some feet on the Antuino cabinet (it just seemed like the right thing to do). 

Antuino has already proven to be very useful as an SWR analyzer.  I know have a much better understanding of the SWR bandwidth of my wire antennas. 

And it is very useful in evaluating the passbands of filters.  I had an old 11.273 MHz filter from an old CB radio in my junk box.  I have no specs on this device -- I didn't know what impedances it was designed for.   So it was time for some Antuino technical detective work. 

First, take a look at the filter with nothing between it and the Antuino.  Input and output on the Antuino are 50 ohms, so here is what the passband looked like with 50 ohms: 

Next I put in two 47 ohm resistors, one in series with the input, the other in series with the output.  Antuino connected at the other side of each resistor.  Here is what it looked like.  Note the improvement in skirt shape.  But there is still a lot of ripple in the passband: 

Then I went to 100 ohms.   The passband ripple was reduced noticeably: 

Then up to 330 ohms.  Here the passband doesn't seem quite as flat as it was with 100 ohms: 

Finally, 1000 ohms.  Definitely too much.  Note the ripple. 

Farhan prefers the passband with the 100 ohm resistors.  I agree.  

BTW the filter is from TEW of Tokyo, Japan.  Model FEC-113-2  11.2735 MHz  No. 2   A    2
It had three crystals on the board with it:  11.275 and 11.272 -- these are obviously for LSB and USB.    The third crystal is at 11.730 MHz, indicating to me that they had a second IF of 455 kHz in this rig.   If I use it, I think I'd stay with single conversion. At 11.273 MHz the filter is of ideal passband width for SSB.  I do feel the urge to build something around this filter. 

Doing the mods on the Antuino was fun, and having worked on the device at least a little bit I feel more of a connection to it. 

Sunday, December 8, 2019

ZL2CTM's Inspirational Tramping Transceivers (videos)

Charlie Morris ZL2CTM is working on portable (tramping) transceivers. Check out his amazing and innovative enclosures and circuit boards.  Really nice. A great way to keep that beautiful circuitry visible. 

More details on Charlie's blog:

Thanks Charlie.  Happy trails!  73

Saturday, December 7, 2019

VK3HN's Inspirational AM Receiver (video)

I'm always delighted when I check the SolderSmoke blog and YouTube list (right hand column of the blog) and find a new post from Paul VK3HN.  And this morning's post is especially good. 

Paul has built an AM receiver. Above you can see his video.  Here is his blog post with details:

This is the kind of blog post that makes you want to heat up the soldering iron and start searching through the junk box.  I'm thinking about putting Paul's 6 kHz filter in my 40 meter HRO-ish receiver.  And I may make use of his AM detector circuit.  And maybe I can put that same receiver on 75 and 160... And then there are the SW broadcast bands... See what I mean?  

Thanks Paul.  73  

Friday, December 6, 2019

My QRPp Signal Arrived in Utah -- 100 mW, 1950 miles, 26 db Above the Noise!

So yesterday morning I was calling CQ on 40 meters with my ET2 two-transistor 100 mW rig.  Later, I took a look at the Reverse Beacon Network (RBN).  Among the East Coast skimmer stations that regularly pick me up I saw an  outlier:   WA7LNW in Utah.  He's 1950 miles from me. And the RBN reported that his receiver had me at 26 db above the noise.  

Here is a screen shot of the RBN report.  Note the time: 1234 UTC.  Around sunrise here -- so gray line conditions.   

But the really BIG factor explaining that 26db s/n ratio is WA7LNW's location: 

"Realtime spots are being received at this location and uploaded to the Reverse Beacon Network."

"CW Skimmer antenna is located on cliff edge overlooking the Virgin River Valley, 1,200 ft. below."

We reported on the WA7LNW RBN station back in 2013:

Check out Jack's page: 

RBN is an important resource for QRPers and homebrewers.  Three cheers for Jack and all the skimmer stations.  Thank you all.  

Tuesday, December 3, 2019


On December 1, 2019,  my 100 milliwatt signal flew more than 500 miles to reach Tony W4FOA in Chickamauga, Georgia. And -- icing on the cake -- this was a random contact.   Tony just heard my CQ on 7038 kHz -- he had not been alerted to my CQ by any spotting site or by the SKCC Sked page.  I made a quick video of my side of the contact (above). 

In a follow-up e-mail Tony explained how my CQ sounded to him: 

"I was just listening on the 40 meter band and having been a QRP'er for 50+ years, I tend to notice the weaker stations, thus explains my calling you.  Also, your signal had that little "sound" of "yesteryear" when signals were not all pure, hi.  Had it not been for the QSB and QRN we could have had a long chat despite the weak signal from your QRPp.  Over the years I have QRP DXCC, 2 way QRPARCI WAS, and my best DX was two QSO's with 2 different VK7 stations on 40 when I was running 1 watt.  I've had a lot of different QRP rigs and still have some home brew stuff plus a couple of HW8s, HW9, Elecraft K2, etc..."  

From Tony's page, we learn more about his ham radio activities (note his homebrew rigs and his obvious affection for the Drake 2B and 2BQ) 

First licensed as WN4FOA in April 1954. Other calls held include EL2AD, 7Q7AA, PY1ZBA. Prefer to work CW but I do work some SSB, primarily DX-related. Enjoy chasing DX on all HF bands. Have 9BDXCC and I now have worked and confirmed all of the current DXCC countries . I enjoy QRP operation and currently use an Elecraft K2 (#2213),Ameco AC-1, Kenwood TS-130V SW-40, DC-40, HW-8 (2), Heathkit HW-9 Deluxe (WARC) PSA-9 HFT-9B SP-99 HM-9 HD-420 VLF, MFJ 40T and MFJ 40V VFO,  and a homebrew 6AG7/6L6 or a 6C4/5763  etc. I also enjoy operating boatanchor gear which includes a Johnson Viking Adventurer, Viking Challenger,  an Eico 720 and an Eico 723 with a HG-10B VFO and a Heath AT-1 and a Drake 2NT. Recently added a neat Lysco 600 transmitter and a Knight Kit T-60, Johnson Viking II, and a Ten Tec 544.  Boatanchor receivers include a Hallicrafters SX-100, SX-110, SX-71, Drake R4C and the incredible Drake 2B/2BQ combo. Recently added a Kenwood TS-830S, VFO-240, AT-230 and SP-230.

Tony W4FOA
Thanks a lot Tony.  73

Sunday, December 1, 2019

ET-2 Contact #16 -- Pete, KD2OMV, Builder of a 6T9er (with video)

Yesterday I had my  first contact using the ET-2's improved receiver.  I had watched the video of N0WVA's receiver and I realized that more sensitivity was possible.  So I tried to replicate his LC ratio. I think that helped a lot.  Today I posted a plea for help on the SKCC Sked page and then called CQ on 40.  I was answered by Pete, KD2OMV who was so loud that I had to take the headphones off my ears!  He was booming in, all the way from upstate New York. The receiver was running off a somewhat depleted 9 volt battery.   I made a quick video (above).  I'm just holding the I-phone up to the headphone, while also trying to copy the incoming CW. 

This was a really great contact.  Pete has a wonderful knack story.   He was licensed as a kid but never made a contact.  As an adult he found his old box of parts for a 6T9er in his parents house. So he builds it and uses the homebrew rig to make his first ham radio contact.  FB Pete. Thanks for the contact OM.  I wrote your call on the ET-2. 


Saturday, November 30, 2019

Mr. Carlson's Analog Panadaptor -- "Like a digital waterfall, but fun!"

We've been talking about Panadaptors -- especially about NON-DIGITAL Panadaptors.  Kind of like waterfalls without the digital water.  A while back I rigged up a very crude non-SDR panadaptor using my Feeltech sign generator, my Rigol 'scope and a DITX40.   Here it is:

In the above video Mr. Carlson looks at the old PCA-2T-200 Panadaptor.   The first five minutes give a really good overview of how the device operates. At around the 5 minute mark Mr. Carlson notes that modern digital receivers have SDR based waterfall displays, but noted (correctly!) that "that's no fun!"   Thank you Mr. Carlson. 

Friday, November 29, 2019

Follow-Up on Scratch-built BITX17 -- Board Map and Video

In my last post I put up a time lapse GIF of my BITX 17 build from about six years ago.  Above you can see my drawing explaining what each of the stages that you see popping up on the board wereMore diagrams here:
And a lot more info on this build are available on this blog.  Just use the search box for build updates (but be aware that this search will also bring up updates on later projects). 

Above is a slightly out-of-focus video tour of the board. 

I'm posting this stuff partly in reaction to the news that the BITX 40 module is no longer for sale.  I hope these posts will serve as a reminder that it is quite possible to homebrew from scratch your own BITX transceiver.  This is a fun and rewarding project.  Three cheers for Farhan! 

Wednesday, November 27, 2019

How A Homebrew BITX Comes Together

This is a bit of a blast from the past.  When I was building my BITX17 I paused after placing each stage on the board and took a picture.  Here is the animated GIF.  

Monday, November 25, 2019

SolderSmoke Podcast #215 Regen Madness, KWM-4, Paesano, Mailbag

Latest N2CQR version of N0WVA's Regen
SolderSmoke Podcast #215 is available. 

25 November 2019

Happy Thanksgiving! 
Transit of Mercury
Book Reviews 

Bill's Minimalist Adventures:
-- 15 Contacts with the ET-2 
-- Ethical issues:  Is spotting yourself OK?  OK to use TWO FETs? 
-- Using Reverse Beacon Network
-- How to keep receiver on the right frequency
-- N0WVA's receiver sounded better, so I built a second N0WVA receiver
-- Regens reach back to Edwin Howard Armstrong's 1912-1923 breakthrough
-- Regens are fun, but they are not good projects for new builders. 

-- Pull out those Michigan Mighty Mites and listen for yourself via on-line SDR receivers.

Pete's Projects: 
-- Left Coast SSB -- "The Paesano" -- To be featured in December 2019 SPRAT. 
-- Pete's KWM-4 on The Collins Collectors Net
-- Pete builds an N0WVA regen -- just in time for Sweepstakes CW Saturday! 
-- Arduino IDE Library trouble
-- uBITX 6.0? Fake News? 

No more BITX40 Modules.  Long Live BITX40 HOMEBREW! 

BITX-101.   Intriguing but on second thought, no.   


Steve Silverman:  Lexicon:  "Audible Modes." 
Felipe CU2BD   Old buddy from the Azores
Michael Rainey AA1TJ:  Come back Mike!  The ionosphere needs you! 
Jack Welch  AI4SV is in 5G land  (Cyprus, not the cell phone thing). 
Walter AC4IM is at the San Vito Solar Observatory in Italy.  DO SOMETHING WALTER! 
Kostas SV3ORA has an amazing homebrew web site.  Thanks Kostas! 
Mike KC6SAX -- How to deal with the frustration of HB projects that don't work. 
Paul KL7FLR -- Pete is 7 Hz high. 
Keith W3ISZ  sent his photo of the Transit of Mercury.  



N2CQR's ET-2 with callsign Tattoos 

Thursday, November 21, 2019

Notes and Video on Doug N0WVA's Amazing Single Transistor Regenerative Receiver

When I had trouble getting the regen receiver in W2UW's ET-1 circuit to work, I turned to the internet and -- through AA7EE's site -- found the circuit of Doug N0WVA.   This circuit has completely changed my attitude toward regen receivers.   I have been exchanging e-mails with Doug -- below is a compilation of the info and regen-wisdom that he has shared.  More to follow... Thanks Doug. 
From Doug N0WVA: 

I came up with the diode after exploring ways to ditch the source r/c combo. The thinking was the closer I could get the source to ground the less voltage/capacitance fluctuations the gate would see.  Also I hated seeing everyone using .01 bypass to avoid audio oscillations and also losing audio gain. 

 The green LED works good but even better is directly grounding the source. Then feed a small negative bias through the gate leak resistor , adjustable via a potentiometer.  

On video, the audio is taken straight from the radio shack headphones that are connected to the audio transformer. The headphones are held directly to the phones case ( no hole for the microphone seen on the phone)  

The variometer is  made with I think a 1.25 inch pill bottle and the tickler inside is around an inch in diameter pill bottle. I used a pharmaceutical syringe's outside tube for a shaft. The tickler form has a couple holes cut for the shaft to pass through, it is a friction fit, more like slits cut and the rod pushed through. I used the soldering iron to melt round holes on the actual outside coil form for the shaft to turn on. On the back of the shaft is a small screw that goes through the outside coil form and screws into the syringe center hole that holds it in place. The tickler is one turn, I think, and routed through the inside of the shaft via small holes melted with the soldering iron.

A couple tweeks to mention is instead of a resistor in the gate, use a choke for less noise, makes a big difference, especially if you listen to AM.  Also I have been using a gimmick for the gate cap.  Just maybe a #36 enamel wire wrapped around  the hot tank lead 5 or 6 times and then I remove turns till the thing stops oscillating, then add a turn. This helps cut down even more on strong signal pulling. 

I have always been on a quest for more performance out of the least parts. This design was about as far as it could go, I think....

I have never done any real sensitivity tests on the regen, so you have gone farther than me already. One thing was noticed though is the gate resistor does add a lot of noise, especially noticeable just under oscillation in AM detection mode.  So I took a one meg 1/4 watt resistor and wound as many turns of #38 wire on as I could, probably around 80 turns, then subbed it out for the gate leak.  This dramatically improved the noise level just under oscillation. This was with a simple antenna band noise test. I think it also improved the noise under oscillating conditions. 

Adding extra antenna coupling will probably help a lot, but, there is a point where we start getting too much strong signal pulling.  The strong external bias battery trick will also improve this, although at the cost of extra parts.

Wednesday, November 13, 2019

Transit of Mercury, 11 November 2019, and a Transit of Venus and Some Sunspots from 2012

Above:  Transit of Mercury, November 11, 2019 as I saw it from Northern Virginia using a 4.5 inch reflector with image projected onto a white paper.  Elisa took the picture with her I-phone.  Arrow shows Mercury.  I almost missed it -- Billy texted from college to remind me of the big event. 

Above:  Transit of Venus June 6, 2012 as seen from Northern Virginia.  Billy (age 13) took the picture with his I-phone 4.  Venus is much bigger, much closer and much easier to see.  Near the bottom edge of the solar disc. 

Above;  Billy on November 12, 2011 with the 4.5 inch Tasco Reflector that was used on BOTH the Venus and Mercury transits (we projected the image on paper). On this day we were using our newfound solar photography expertise to take a picture of sunspots (our picture below). 

Ah, those were the days!  Many spots back then.  None now. 

Tuesday, November 12, 2019

Listen to the ET-2's Minimalist Regen Receiver

I'm guessing that most of you have never listened to a regen receiver that uses only one transistor.  So in these videos I've tried to capture the experience.  The audio that you hear from the receiver is from a small I-phone microphone taped to the one of the headphones on my DLR WWII headphones.  So you are hearing it just as I hear it -- with no additional amplification. 

Here is N0WVA's schematic.  When I tune the "regeneration" control I am turning the knob on the variometer.  The broad or "bandset" tuning control is essentially N0WVA's 25 pf cap.  My fine tuning control (the one that I use the most in the video) is the equivalent of the smaller cap in parallel with the larger tuning cap. 

I had trouble shooting the video for this post -- taping the mic to the headphone turned out to be a bit difficult.  So I ended up with a few extra (and imperfect) videos.  I include them here for anyone who might want to listen some more to a single transistor regen.  (I have a few more -- let me know if you'd like to see them!)

In the next one, at the end I throw the switch to transmit allowing you to hear what "sidetone" sounds like on the ET-2

Monday, November 11, 2019

SV3ORA's Amazing Homebrew Web Site

Kostas Giannopoulos has  a lot of really great homebrew information on his QRP web site.  It is reminiscent of the JF1OZL site. Check it out: 

For an example that his apropos of recent ET-2 discussions, Kostas has an extensive page with  many, many versions of his hyper-minimalist rig:  

Link to this project:

Thanks to Kostas for putting together such a great site.  And I really like the name of the site: Discrete Electronics.  FB. 

Saturday, November 9, 2019

SPRAT, the FETer, DLR headphones, and recent QSOs on the ET-2

Yesterday we had QSO #13 on the ET-2.  This was with Jim W1PID.  In an earlier contact Jim told me I had some chirp.  I fiddled with the coupling cap and the bias pot and am now T9!  These days, chirp is an endearing, nostalgic problem to have.  Thanks for the report and QSOs Jim! 

Contact #9 was with Fred K9SO.  He is in Wisconsin and put our distance at 633 miles.  That is our DX record so far.  Not bad for 92 milliwatts to a dipole on 40 meters. 

Most of my contacts come as a result of pleas for assistance on DX Summit or the SKCC Sked page.   But I did make one "random" contact: Contact #6 with N2VGA.  He just heard my CQ and gave me a call.  FB. 

I checked to see if OM Glen Yingling W2UW -- the guy who started all this with his ET-1 -- is still around.  He became a silent key in 2012.  But his ideas live on... 

SPRAT 137 (Winter 2008/09) has a great article by QRP hero G3XBM.  Roger built a version of the ET-1.  His was for 80 meters and he called it the FETer.   FB.   I was struck by his estimate of the sensitivity of the ET-1 receiver: -100 dbm.   I measured the N0WVA receiver (the one that I am using) has having a minimum discernible signal of -93 dbm.  Pretty close.  We may be at the limit of what you can expect from a single transistor receiver. 

SPRAT 137 had something else that really resonated with me.  G3YVF had an article on a minimalist rig using only one 6V6 tube.  Geoff opened the article with this warning "Don't try this unless you have a set of balanced armature type DLR 'phones as they are really sensitive."  I have a collection of old headphones that I picked up at hamfests in London years ago.  When building the ET-2, I checked all the old phones for sensitivity.  A set marked DLR was the most sensitive.  So Geoff's observation had been independently confirmed.   QRP Quarterly had an article comparing the sensitivities of old headphones -- we should dig that article up.   

SPRAT #137 is a reminder of what a great resource SPRAT -- The Journal of the GQRP Club -- really is.  As we say on SolderSmoke, if you are not a SPRAT subscriber you are just wrong!  Here is how to join GQRP and subscribe to SPRAT:

Thursday, November 7, 2019

The ET-2 with Callsign Tattoos

Slots are still available! 
Get your callsign on the ET-2!

This rig will probably soon turn into wall art here at SolderSmoke HQ.  With this in mind I have started writing on the wooden base of the rig the callsigns of all stations worked. So far we have 10.   There is space for more.  

Frequency is 7038.6 kHz.    I usually try for contacts around 1430 UTC (0930 Eastern) and again at around 2130 UTC (1630 Eastern).  I post messages asking (pleading!) for assistance on the DX Summit site and on the SKCC Sked board.  

If you are within reasonable range for a signal in the 100 milliwatt range (antenna is either 40 meter NVIS dipole or a doublet) please keep an eye on the DX Summit and/or SKCC sites and maybe try to have a contact.  

Background on the rig here: 

Wednesday, November 6, 2019

Contact #10 with the ET-2 -- Perry K9NZ

Perry K9NZ was contact #10 with my ET-2 QRPp rig.   I found the above on his QRZ page.  Beautiful sentiments.  Most of us have similar stories, and similar feelings about ham radio. FB Perry.  

Tuesday, November 5, 2019

For All You Guys Who DON'T Use the Proper Fuse Value

Pete has been trying to talk sense on this issue for a long time, but some folks just won't listen. 
You need to have a reverse polarity protection circuit in your rigs AND you need to carefully determine fuse size needed for normal operation.  If your final transistors for some reason start pulling more than the normal amount of current, the fuse will blow before your PA transistors release their smoke. 

Monday, November 4, 2019

Melbourne Australia -- QRP By the Bay 2019

Each November, Peter Parker VK3YE and his ham colleagues from Melbourne share with us reports on Peter's annual "QRP by the Bay" event.   

I think VK3HN should seek a trademark for that hat.  As soon as I saw it on the table in the video above, I knew these were Paul Taylor's rigs.  FB Paul.  Here is Paul's report:

Great work guys.  Thanks a lot.  73 

Saturday, November 2, 2019

SolderSmoke Podcast #214 is FINALLY out!


4 November 2019 (shockingly late!)

The visit of Farhan to Northern Virginia
"I heard this guy from Southern California on 20..."
Fire Report from Pete

Pete's Bench Report
"When you know stuff, you can do stuff!" 
The CRAP rigs 
Old Boatanchors -- the Swan 120  with SUPER STABLE ANALOG VFO! 
Ten Tec rigs dial cord replaced with Chinese digi sig counter 
Pete's 500 mW encounter with a QRO curmudgeon
The ZL2BMI Challenge has Pete building crystal filters
The Left Coast Loafer CW rig 

Bill's Bench Report

ET-2 Refinements
N0WVA's Regen Receiver 
Going from ET-1 to ET-2
J-310s vice MPF-102
100 mW from a single J-310
Receiver kind of deaf -103 dbm MDS
10 contacts so far in 9 states 
THREE contacts yesterday.
Worked Wisconsin - 633 miles on 92 mW 
We are at sunspot minimum. 
"Rage, rage against the dying of the light." 
Simplicity is the real reason for CW 

IDEA:  Get those Michigan Might Mites on the air! 
Use Reverse Beacon Network to see if you are getting out 
Use SDR receivers to make contacts


Friday, November 1, 2019

Don't do this yourself...

...or else you'll be spending a LOT more time on 17 meters. 

Direct Conversion (videos)

Here are a couple of videos from 2017 (never posted before).  I built a little 40 meter Direct Conversion receiver for my nephew John Henry.   

Whenever we work on circuitry like this, we should be be grateful for Wes Hayward W7ZOI who, in a 1968 QST article, reminded us of this important but until-then forgotten technique. 

More information on this project appears in these links:

Friday, October 25, 2019

Minimalist Masochism at Solar Minima -- But More Contacts with the ET-2

Dylan Thoams
  "Rage, rage against the dying of the light" 

I thought of that line from Dylan Thomas's poem when I read on G3XBM's web site that we are kind of at the very bottom of the solar cycle.  Roger wrote on 22 October: "Solar flux is 64 and the SSN 0. A=5 and K=0. As far as I am aware this is the lowest solar flux this solar minimum."   

I also thought of this as I pounded brass (Indian brass!) in an effort to make a few more contacts with my ET-2 two transistor rig.  Obviously venturing forth on 40 meters with just TWO transistors (one for transmit and one for receive) and crystal control AT SOLAR MINIMA is not for the faint of heart.  It is almost a Dylan-esque act of defiance. 

I have had to resort to please for help on the DX Summit, the SolderSmoke blog and the SKCC Schedule page.  Fortunately for me, the brotherhood has sprung to my support.  

W1PID (who gave me contact #3) also gave me contact #4 on 21 October. 

W4KAC in Hickory NC was contact #5.  This was on 22 October.  This was the only marginal contact so far.  He was running 5 W into an end fed half wave. 

Yesterday was a big day for the ET-2. I had two solid contacts: 

#6 was N2VGA in New York UPDATE:  Larry N2VGA confirmed by e-mail that this was a "random" contact -- not the result of my on-line pleas for assistance.  He just heard my CQ and responded.  FB.  

#7 was K4CML in Newport News, Va.  He switched to QRP himself at 2.5 watts for a nice 2X QRP contact. 

Looking at my Rigol 'scope, I now think I'm putting out about 150 milliwatts.  Not bad for a single J310.  I may have to invest in a heat sink.

40 seems most cooperative in the morning (around 0930 local) and again in the afternoon (around 1630 local). 

Thanks to all who have helped.  I will try to make a few more. 

Radio Telescope Homebrewed from Cake Pans and Chicken Wire

Tuesday, October 22, 2019

Revamped SolderSmoke YouTube Channel -- Please Subscribe

I did some work on the SolderSmoke YouTube Channel: 

And I added a bunch of videos that had somehow ended up in different channels. 

Please visit, watch some of the videos and subscribe.  From now on I will put all of the videos in this channel.   

Thanks!  73  Bill 

Monday, October 21, 2019

Farhan Visits Northern Virginia and SolderSmoke HQ

Our good friend Farhan came to Northern Virginia last week for the 50th Anniversary Symposium of AMSAT.   We were really delighted that he also came to SolderSmoke HQ.  Elisa and I gave him a lightning tour of Washington DC (including a quick visit to The Air and Space museum) and then we headed back to the shack from some radio work. 

In the picture above you can see my BITX-20 (that Farhan designed) off his right shoulder.  Off his left shoulder you sits my ET-2 rig.  I really wanted to show Farhan how well the N0WVA regen performs -- he was impressed, especially when we started listening to SSB contacts. It was really amazing that we were doing this with just one J-310 FET.  This was great fun.  Farhan tells me that he will soon take up the "two transistor challenge."

When he was here in 2017, I tried to demonstrate my version of Rick Campbell's R2 Direct Conversion receiver.  Unfortunately, when I tried to show off the "single signal" capability that is the whole purpose for this receiver, it was NOT producing a single signal output -- you could hear the signal on both sides of zero beat.   One of the small AF chokes I had used had gone open, knocking our one of the two DC receivers.  This time I had the problem fixed and single signal reception was successfully demonstrated.  

Farhan brought me two pieces of test gear that I have needed for a long time:  A step attenuator and a two tone generator.  Paired with his Antuino, these devices will bring about a big increase in capability on my bench. 

It was really great to have Farhan in the shack.  We had a great time talking about ham radio and homebrewing.  Elisa and I both really enjoyed hearing from Farhan about his travels and about his life in India.  We are all really lucky to be in the same hobby as Ashhar Farhan. Thanks for the visit Farhan.

Here is a quick video of Farhan tuning the BITX 20.  

Saturday, October 19, 2019

QSO #3 with the ET-2 Minimalist Transceiver

The Radio Gods were clearly supporting me on 16 October 2019.  I had sent out a plea for people to listen for the 80 mW CQ from my ET-2 rig.   I had specified 0930 Eastern as the time.  Little did I know that there would be a contest at that hour (on a Wednesday morning!) on 40 meter CW.  There was no chance of my signals getting through.  I leaned that the contest would be over at 1000 hours, so I waited and called CQ again at that hour.  Jim W1PID had guessed that I would do that.  I immediately recognized his call -- he was often at the other end of Michael Rainey's most daring low-power adventures.  He was a participant in the famous Rexpeditions, including a coastal effort to send Michael's voice-powered CW signal across the Atlantic.  His normal operating habitat is in the field.  We had a wonderful QSO.  He told me I peaked at S-6.  

I have worked W1PID on at least two Straight Key Nights and this blog has had many postings about his long-standing involvement in QRP. 

Thanks a lot Jim! 

Tuesday, October 15, 2019

Please Listen for My 80 Milliwatt CQ Tomorrow, Wednesday 16 Octoberr

I will be calling CQ from Northern Virginia starting at 1330Z (0930 Eastern) on Wednesday 16 October 2019 on 7038.6 kHz with my ET-2 QRPpp rig.   I have made two contacts so far -- both contacts were at a range of about 300 miles.      I'd like to be able to make at least one per day.   If you are within range please listen for my CQ tomorrow and give me a call.  

Thanks and 73  Bill N2CQR

Monday, October 14, 2019

The First Sunspots of Cycle 25 -- Explained by Space Weather Woman (Video)

Dr. Tamitha Skov explains how Cycle 25 has begun while Cycle 24 is not quite finished. 
She has a very clear way of presenting the space weather.  Very useful. 

YouTube site:

Sunday, October 13, 2019

More on the ET-2 : Better Pictures and More Circuit Description. Some Thoughts on Simplicity

So yesterday I made my first contact using my ET-2 rig.   Last night I got an e-mail from Gary, the fellow at the other end of that contact: 

Evening Bill, N2CQR….Yes I did learn about you from the spot on the DX Summit cluster. I tuned to the freq to see if I could even hear your 80 mW and you were a good real 569 when calling CQ.  You built up to a real 589 on the later transmissions. I did not have either of the two pre-amp positions on in the ICOM 756 Pro II. There was not any QRM on the freq either. Your spot indicating the 80 mW is what really got my attention.

My antenna is a 2 element yagi at about 115 ft and it really works great for me.

Thanks for the picture of the great little transmitter. Glad to be your first DX QSO with it. Hi Hi  Maybe again soon.  My pleasure to work you.
73, Gary, K4MQG
Fort Mill, SC

Farhan commented on yesterday's post, saying that it was hard to tell (from my pictures) where he rig started and ended.  He was right.  So this morning I have tried to clean up my bench a bit -- I hope these pictures are better.  

Above you see the whole rig.  The transmitter board is right next to the key that Farhan gave me.  You can see the 7040 crystal.  A C-Clamp holds to the bench the piece of scrap plywood that serves as the base for this rig.  Next to the C-Clamp you see the TR switch -- the just switches the antenna -- both transmitter and receiver are powered at all times.  I can hear the transmit signal in the headphones and this serves as my sidetone. 

Here is a close-up of the transmitter with the schematic below: 

The transmitter is VERY simple.  Nine parts, including the low-pass filter.  You can barely see the J310 FET to the right of the crystal. 

Here is the receiver:

I really like N0WVA's regen.  The green diode in the source circuit is the key.  This one does not squeal when you go into excessive regeneration (when you think about it, regens should NOT squeal at audio frequencies -- but most do).  Also, the green diode dims a bit when you are at the right amount of regeneration.  In the picture you can look down the tube of the variometer that Pericles HI8P gave me many years ago.  The big variable cap is from the junk box -- I think it may be from a Johnson Viking transmitter.  Note the long shaft with the insulating connector -- this is to reduce the hand capacity effect.  On the right you see a smaller cap with just one vane -- this is my fine tuning control --- with the smaller cap at mid range, I would just set the big capacitor to put the receiver at 7040 -- with the smaller cap I could tune +/- 12 kc.  I also used an insulating shaft on the smaller cap -- the connector for this one is from an old 1930s era regen that I picked up at the Kempton Part rally in London.

Instead of the audio transformer and Radio Shack headphones, I just used some old DLR-1 WWII Headphones.   They are very sensitive and work well. 

Lots of soul in this new machine:  The variometer from Pericles.   The WWII headphones.  The 1930s era shaft connector.  The circuit idea from the Autumn 2001 SPRAT.  Farhan's key. 

I recently read on Hack-a-Day of a new FPGA chip that has on it 35 BILLION transistors. I'm sure that thing can produce some fascinating results, but can anyone really understand it, or feel that they really BUILT something that has that kind of chip at its center?   On the other hand, I did rely on a lot of modern digi technology in this project:  The Reverse Beacon Network reported back that my unanswered CQs were in fact getting out (one as far as Kansas to K9PA).  And in the end I had to ask -- via the DX Summit Spotting cluster -- for someone to listen for me.   So I can't go full Luddite here.  And I wouldn't want to have to use a rig this simple every day.  No way.  It is just too hard to use. But there is a beauty and a challenge in simplicity.  There is some virtue in using just two transistors instead of 35 billion. 

Thanks to N0WVA, W2UW,  VU2ESE, HI8P, K4MQG, The G-QRP club and their inspirational journal SPRAT, the RBN and the DX Summit. 
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column