The Awesome Homebrew of Will KI4POV

 

Will's homebrew station is really something.  The rig (it truly qualifies for this term of praise) is amazing all by itself  (see below), but a look at Will's QRZ page reveals other ingenious inventions and techniques:  There is the clock made from panel meters.  And the method he uses for making aluminum project boxes.  He even made an N0WVA regen receiver.  That's the one I used in my ET-2.   Fantastic.  

Will really needs to share his homebrew skills with others.   I hope he is soon in a local high school teaching students how to build things.  Thanks Will!  

Bill and Pete,

Just wanted to send a note to update you on the latest projects here. The last time I emailed, I mentioned wanting to build a superhet, which you (rightfully) discouraged, pushing for a DC receiver.

Well, I finished the superhet at the end of last year. I had most of the receiver working long before then, but got bogged down in an AGC system. The final receiver is a 5 band si5351a controlled single conversion superhet loosely based on Todd, VE7BPO's design with several modifications. I used a 9 Mhz IF instead of 4, I used a digitally controlled LO and BFO, and as mentioned, I added an AGC system, which ended up being the most challenging (and most interesting) part. The final AGC system I ended up with used the detector and amplifier side of Wes Hayward's "full hang" AGC from SSDRA, but I didn't have the IC IF amplifiers with variable gain, so instead, it fed a PIN diode attenuator circuit to control the IF gain. The final result worked great, but I nearly pulled my hair out getting it to work. I originally intended to build the receiver for 40 and 20 meters, but it ended up covering 80, 40, 30, 20, and 15 since I used the filter relay board from QRP Labs which had 5 slots.

After I got the receiver running, I decided I needed a matching transmitter, so I  built up a simple CW transmitter to match. It uses an si5351a VFO driving a 74HC04 hex inverter as the buffer amplifier. The trick here is that by driving all the inverter gates in parallel, the output impedance is ~14 ohms broadband, suitable for driving a BJT PA without any need for matching transformers. The PA is 3 2N2222s in parallel with heat syncs putting out about 2 watts from 80 - 15.

The part I'm most proud of is that I have the arduino for the receiver connected to the arduino for the transmitter through a serial line. The receiver sends it's current frequency to the transmitter so that the transmitter can track the receiver's frequency as you tune (like a transceiver). I'll attach a few pictures of my homebrew station below. The transmitter is on the left, receiver is on the right. The box on top of the transmitter is my homebrew keyer. Next up on my build list is a solid state T/R switch.

Bill, I've enjoyed following the updates on the school DC receiver build. My local club is wanting to do some youth outreach, and I'd love to get them involved in building. I'm the only builder in the club though, so I don't know if I personally have the manpower to make it happen. Also, thanks for the recent info and pictures of Cuban homebrew rigs. I grew up listening to Arnie Corro, so I love seeing their resourcefulness and ingenuity. Makes me want to take apart some old electronics.

Pete, I'm enjoying following the 10M SSB project. With the uptick in propagation, I've been bitten by the 10M bug, and I'm thinking a 10M rig may have to be on my project list for this year.

73,

Will - KI4POV

KI4POV's Clock

KI4POV's N0WVA Regen

The Lamakaan Annual Radio Convention Starts Today!

 

The Lamakaan Amateur Radio Club's annual convention begins today in Hyderabad, India.  This is Farhan's club so it is sure to be a great event.  Presentations are being live streamed on YouTube and on the QO100 geostationary satellite. 

Here is the link to the convention: http://www.larc.in/larc4/

Pete N6QW will be the first presenter and will talk about his new PSSST Rig. He will be speaking at 0430 UTC Saturday 11 December.  That is 11:30 pm on Friday, December 10 on the East Coast of North America.  

I will be speaking at 1130 UTC on Sunday December 12.  That is 0630 Saturday 11 December EST. I'll be talking about the Mythbuster rig and about the ET-2. 

Here is the schedule.  

Here's a time zone converter: https://www.timeanddate.com/worldclock/converter.html?iso=20211211T043000&p1=505&p2=250&p3=137

Here is the Lamakaan Club's YouTube Live Channel.  https://www.youtube.com/watch?v=cRznKwGgvDo

I don't know how we might be able to watch or listen via the QO100 satellite.  The U.S. is not in the footprint of this bird.  But there is a good WEBSDR receiver run by BATC and AMSAT DL: https://eshail.batc.org.uk/

Hangin' it up (the ET-2)

My ET-2 minimalist QRP CW adventure is (for now) officially over.   I have taken the rig - festooned with the callsigns of all the stations I contacted -- and have put it up on the wall.  This may be a new form of art.  I think I am the first radio amateur to do this.  I think it is pretty cool. 

Here are the stats:   I made 20 contacts with the rig. I had it on the air from 12 October 2019 to 7 December 2019.    Seventeen of the contacts were the result of my posting pleas for help on the SKCC Sked page and/or the Summit DX page.  Three of the contacts were completely random. One station -- W1PID -- provided four of the contacts.  Thanks Jim. 

My power out was usually around 100 milliwatts.  I used either a 40 meter coax fed dipole or a 135 foot doublet fed with window line. 

My best distances were Wisconsin and Georgia. 

Crystal control was the real limiting factor.  100 milliwatts didn't seem to be much of an impediment. The most amazing thing about this rig is the N0WVA regen receiver.  It took a lot of peaking and tweaking, and it took some skill to operate. but once I got it going it was an amazingly good receiver.  Really Amazing for just ONE J-310 FET. 

The last contact was really nice.  I was calling CQ and AA8OZ came back.  He was in a cabin on a trip with some scouts.  He too was on a wire antenna.  He was one of those guys who said WOW! when I told him about the rig.  We had a nice long conversation on 40.  It was a great way to wrap up the ET-2 adventure. 

Thanks to all who helped me make contacts and for all those who tried to work me. Thanks to N0WVA for the regen inspiration. And thanks to Glen Yingling W2UW (SK) for the ET-1 idea. 

The rig is standing by.  On the wall.  Perhaps it will return to service, maybe during solar max. 

Crystals -- Old and New and World War Two

I was watching Greg Charvat's great video about the WWII ARC-5 receiver yesterday. Greg admonished all of us to preserve any WWII gear we might have in our shacks.  Just one day earlier I had found the crystal pictured above in my junk box.   There is some old stuff floating around in here! I will preserve this one. 

Speaking of crystals,  Walter KA4KXX recently sent me some 40 meter crystals for use with my ET-2 transceiver.  Walter suggested that I use them to check into the daily (1300Z) Sunrise Net on 7123 kHz.  These were modern "short" computer crystals.  So I put them into FT-243 and FT-241 holders.  (Don't worry Greg, no WWII gear was destroyed in the process).  It was kind of fun to put the new rocks in old boxes. They work just fine in the ET-2.  Thanks again Walter! 

Finally, Chris KD4PBJ has been helping a buddy of his buy a Drake 2B.   This morning Chris asked about the E Crystal adjustment coil on the back of the Drake.  I told him that was to allow the use of "overtone" crystals.  But, sadly, I advised him not to worry about it too much because the days of ordering bespoke crystals (overtone or otherwise) are behind us. 

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:  https://soldersmoke.blogspot.com/2013/03/edgy-skimmer-antenna.html

Check out Jack's QRZ.com page: 

https://www.qrz.com/db/WA7LNW

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

ET-2 Contact #18 W4FOA -- RANDOM, UNSCHEDULED, AND NOT SPOTTED (Video)

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 QRZ.com 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

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. 

Pete KD2OMV

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.  

SolderSmoke Podcast #214 is FINALLY out!

WE ARE WORKING TO IMPROVE THE AUDIO QUALITY.  IN THE FIRST RELEASE OF THIS PODCAST SOME OF THE AUDIO WAS KIND OF MUFFLED.  I TRIED TO FIX IT THIS MORNING AND I THINK I MADE SOME IMPROVEMENTS.  THE IMPROVED AUDIO IS NOW AT THE LINK BELOW.  

4 November 2019 (shockingly late!)

http://soldersmoke.com/soldersmoke214.mp3

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

MAILBAG
DL1AJG
KC6SAX
W9VNE
KA4KXX
N0WVA
Zl2BMI
AJ6BD  

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. 

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.  

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! 

 

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. 

Success with my ET-2 --TWO TRANSISTOR RIG

 

In my effort to replicate the ET-1 rig of Glen Yingling W2UW, I had a hard time getting the receiver to work well with the single FET being switched between receiver and transmitter, so I retreated a bit and went with individual FETs for the TX and the RX.  This doubled the transistor count -- to TWO.  So it is an ET-2.

I also boosted the power to 80 milliwatts by putting 12 V on the transmitter.  The receiver was running off the 9V battery you can see in the left in the picture. 

Here is the story of the contact: 

To K4MQG from N2CQR:

Gary: Wow thanks for the QSO today.  I was using 80 mW transmitter that consists of just 8 parts!  The receiver was a regen using one single transistor.  So one transistor on transmit and one transistor on receive.  And it reached South Carolina.

I was about to give up hope.  I had been calling CQ for days.  Then I was talking to Rob VE4GV on 20SSB.  Rob suggested that I "spot myself" on one of the DX clusters.  So I did (see below).  Obviously you saw my spot and a minute or so later, SUCCESS!   I'm really pleased.

Attached is a picture of the rig.  The transmitter is around the crystal and the blue pot on the right.  The headphones are from WWII.  The receiver was powered by the 9V battery.  The regen uses a variometer given to me by a friend in the Dominican Republic in 1992.  The main tuning dial is connected to the cap by an adapter from a 1930s-era regen.  Antenna was a 40 meter dipole at about 25 feet.  Obviously your 3 elements a 115 feet were doing the heavy lifting.

Thanks again Gary!

And thanks to Rob for the suggestion on the spotting.

73  Bill N2CQR