Author: Peter Marks

Ralph AB1OP — A New Receiver (with Mojo) and A New Acronym (with Attitude)

Bill and Pete,


😀 Completed the wiring the LBS Part I (pics attached)
I’ve said wiring completed but, it’s not really done. lt will need some peakin’ & tweakin’ and I already have made design changes to the power board.

My Summer Project took ALL Summer, had the usual excuses with Summer activities, family obligations, interruptions and days of just plain goldbricking.

At last all the LBS Part I boards were laid out, etched, populated, soldered and installed. As a novice Toroid winder it took a while to get the toroids done. (I had to do THREE DBM Transformers to get two to match.)

Some features of note:
1. Extensive use of the recycle bin for front / rear panels and feet. (Tin can and bottle caps) Go Green!
2. Extra Mojo was induced with using the 10K pot Farhan supplied with my first Bitx40 Kit that I did not use, (I replaced it because I could not find knobs for 4mm shafts back then)

3. Junk box speaker (8 Ohm – 0.5 W) from a cheap radio alarm clock my Mom threw away after it stopped working.

4. Use of the RG405 coax for interstage RF connections. (No Murphy’s Whiskers)

😞 My tale of woe. Apparently after connecting the LBS Part I stages together I put the AD9850 module back in it’s socket upside down — then applied power, Awaiting the replacement. HIHI

😜 SITB or Stick-It-To-Bezos. Again this month my Ham stuff budget was blown on an Amazon order (replacement AD9850 modules being not cheap anymore). I started at the soldersmoke blog web page search bar so there should be a little something heading to your North Virginia QTH from Jeff.

73,
AB1OP_Ralph

SolderSmoke Podcast #206 — GQRP CONVENTION SPECIAL EDITION

SolderSmoke Podcast #206 is now available:

http://soldersmoke.com/soldersmoke206.mp3

 — SolderSmoke resumes after a busy summer.

 — We did a portion of #206 via Skype at the GQRP Convention. Thanks to Steve G0FUW for setting this up. A portion of our participation appears at the end of the podcast.

— Pete’s SDR Rig and his new involvement with WSPR and FT-8

 — The allure of SDR and the pitfalls of complexity.

— Bill’s 135 foot Doublet, 75 AM, 60 USB and 30 Meter CW.

— Plans to change the IF of Bill’s HRO dial receiver.

— Thinking (again) about sold stateing the HW-101.

— Hans Summers, QCX and QSX rigs.

MAILBAG:

Ralph builds Pete’s LBS receiver. FB!

More Homebrew Wisdom from Frank Harris, K0IYE


 In Chapter 13A, Frank Harris writes:

The Vanishing Art

The 1986 ARRL Amateur Radio Handbook reported that hardly anyone was building homebrew ham receivers…. Out of hundreds of contacts, so far I’ve worked four guys, George, K7DU, Mike, NØMF, Biz, WDØHCO and Jack, W7QQQ who were using homebrew receivers for the QSO. Three of these receivers were made from vacuum tubes. George’s receiver is a beautifully crafted instrument that looks like a commercial design from 50 years ago. All of these receivers had no trouble hearing me on 40 meter CW. I talked to one other fellow, Gil, N1FED who told me he had just finished a vacuum tube receiver. Unfortunately, it was performing so poorly he was still using his modern transceiver on the air. Gil told me he didn’t like transistors. I guess he found printed circuit boards and those pesky oscillations too much trouble. In spite of this pessimism, you CAN build transistorized receivers that work reasonably well. I built mine because I was intrigued by mysterious circuits like “balanced mixers,” “product detectors,” “cascode amplifiers” and “crystal ladder filters.” Before this project, I could recite the purposes of these circuits, but I had no “feel” for how they worked and why receivers are designed the way they are. What better way to learn than to build one?

Aside from the need to shield circuit blocks from one another, a homebrew receiver with a single big board full of discrete components has another problem. If you build the whole thing at once without buying a kit and pre-cut board, I guarantee it won’t work. To make homebrew stuff that works, you have to develop your own technology based on parts you can get and circuits you understand. Learning to think this way was difficult for me. Rather than “building a receiver,” I had to lower my sights and build one circuit at a time, e.g., “an oscillator,” “a mixer,” “an audio amplifier,” etc. Then I put the blocks together to complete my project. Some of these circuit blocks didn’t work the first time so I had to build a new block. There were various reasons the modules didn’t work. Usually, I wasn’t able to buy the exact parts used in the circuits I was copying. Or my craftsmanship or shielding wasn’t adequate. Sometimes I never did learn why one version of a circuit block was superior to another. By building my receiver using separate little shielded modules for each circuit block, I could replace a circuit block whenever I managed to build an improved version. Otherwise, I would have ruined the entire big board.

 On rare occasions my circuits didn’t work because there were errors in circuit diagrams in QST magazine or in the handbooks. I found some serious errors in my 1979 ARRL Handbook and a minor one in my 1998 edition. Perfect editing is not possible, so we shouldn’t expect it.

 GET THE WHOLE BOOK HERE (FREE!)
http://www.qsl.net/k0iye/

“From Crystal Sets to Sideband” — Homebrew Wisdom from Frank, K0IYE (Free Book)

Get Frank’s book here (FREE!) http://www.qsl.net/k0iye/

 I’ve had Frank’s book on the blog many times over the years, but it is a book that merits repeated mention. It is filled with great advice and homebrew wisdom. I found myself looking at it again recently, and at Frank’s QRZ.com page. I came across lots of wisdom that I may have missed in earlier visits. For example:

From the QRZ page:

My version of ham radio is 100% scratch built equipment. I buy nothing manufactured for ham radio except log books…My rig is based mostly on the 1986 ARRL handbook. Modern designs in today’s QEX and Handbooks are usually full of mysterious ICs. In my opinion, they don’t qualify as homebrewing.

From his book (Chapter 15):

I was fascinated by ham radio, but I didn’t learn much about how sideband worked. I had the impression that sideband was MODULATION FOR MILLIONAIRES and too complicated to homebrew. The 1957 ARRL handbook’s opaque descriptions of “phase shifters” and “balanced modulators” only confirmed my opinion.

If you are like me, you will have a devil of a time getting your SSB drivers to produce intelligible speech without hissing and noise problems. All I can tell you is to keep your brain mulling over your difficulties. Shield and filter your prototype until the darn thing works. Keep careful notes so you don’t make the same mistakes twice. Persistence will win in the end.

My sideband transmitters are still in the experimental category. You will find that it takes a great deal of tweaking and fussing to get SSB tuned so it sounds good and doesn’t radiate on unplanned frequencies. You won’t believe how many diseases your SSB transmitter will create for you to conquer! Sideband is not a project for impatient people.

Foreword:

We homebrewers are nearly extinct, but there are still hundreds of us scattered around the world, some are even in the USA. Yes, there ARE American homebuilders! We’re rare, but thanks to the QRP hobby, the number is growing. Even if we homebrewers don’t change the world, I guarantee you will enjoy learning radio technology and building your own equipment.

Get Frank’s book here (FREE!) http://www.qsl.net/k0iye/
THANKS FRANK! Send Frank a thank you note: Frwharris@live.com

QSX! Hans Summer’s New SSB Rig Revealed in South Africa

I liked this video. I liked Hans’ description of his mechanical skills, and the way he has at times become a “human CNC machine.”

This seems like a much more sophisticated rig than the QCX. I may be wrong, but QCX seemed to be essentially an analog phasing rig with a narrow CW audio filter. I kind of expected the SSB version to be a QCX with broader filter, but QSX is a different, more sophisticated, SDR rig.

Once again, three cheers for Hans Summers. We should all pay him to go to those summer conventions — every time he does, something new and important for ham radio comes out of the trip.


Three Cheers for the uBITX! Keeping problems in perspective…

This morning I was looking at Farhan’s uBITX page. He got philosophical at the end of the circuit description:

As a fresh radio amateur in the 80s, one looked at the complex multiband radios of the day with awe. I remember seeing the Atlas 210x, the Icom 720 and Signal One radios in various friends’ shacks. It was entirely out of one’s realm to imagine building such a general coverage transceiver in the home lab.
Devices are now available readily across the globe through online stores, manufacturers are more forthcoming with their data. Most importantly, online communities like the EMRFD’s Yahoo group, the QRP LABS and BITX20’s groups.io community etc have placed the tribal knowledge within the grasp of far flung builders like I.
One knows that it was just a matter of breaking down everything into amplifiers, filters, mixers and oscillators, but that is just theory. The practice of bringing a radio to life is a perpetual ambition. The first signal that the sputters through ether, past your mess of wires into your ears and the first signal that leaps out into the space from your hand is stuff of subliminal beauty that is the rare preserve of the homebrewer alone.
So true! Over on the BITX.io group there is a very interesting discussion of the extent to which the uBITX is in compliance with FCC and ITU specs on harmonic and spur emission. In this discussion, I think it is important to remember the reason Farhan created the BITX rigs: The goal was to get today’s radio amateurs out of their Yaesu-Kenwood-Icom appliance rut, and get them involved with the circuitry, to get them to modify and improve the rig. And that’s precisely what is going on now.
It was well known that dual conversion is riskier than our old familiar single conversion architecture — when you throw another mixer and oscillator into the rig you open the door to problematic spurious signals.. But dual conversion holds out the promise of general coverage. And the advantage of that is quite evident in the uBITX. Mine is on right now and I can switch from band-to-band with a press of the tuning control. This is nice. So a spur has been discovered — solutions are already being offered. That’s the spirit! And it looks like the low pass filters might not be as effective as hoped. This may be a simple matter of board layout and relay use. That is clearly quite fixable.
So let’s remember that this is not plug-and-play ham radio. This is more of a collaborative, homebrew, open-source hardware/software project. The uBITX may be closer to true homebrew than many hams are accustomed to. That was the whole idea.

Patience is a virtue
Possess it if you can
It is never held by techies
And seldom held by hams


Where it belongs: S38E in a Zoo

Hey fellas,
Hope this finds you well. Spent the day with my family at a zoo. They have a neat African exhibit that includes many small huts for shade and to give the feel of the African bush. Each was outfitted with items kne would expect to find in a distant bush camp… Gear, etc. Many had semi modern radio receivers.
But one… One had a well worn and rusting Hallicrafters S38E. The rig y’all love to hate… Lol. It is secured to the shelf and as far as I know stays their year round; partially open to all the wonder weather Michigan can throw at it.
I got a kick out of it, thought you may as well.
Hope all is well.
John in Michigan
KE5ETX
——————–
John: Finally, a good place for these things. Museums. Or Zoos. We should organize a collection campaign, perhaps with free pick-up and tax deductions.

Here is a no-kidding story. We had a family reunion last month. I met a cousin I hadn’t seen in 40 years. I had given him an old S38E so he could listen to SW BC. I asked him if he remembered that radio. “Yea, I sure do — It almost electrocuted me!”
73 Bill
——————



VA3IAW’s BITX 40 Box. Ugly? I don’t think so.

Al VA3IAW thought he had a shot at the “Ugliest BITX 40” award, but I shattered his dream by declaring it a thing of beauty. He made it from PC board material and 1/4 inch angle brackets. That’s a paint stirrer supporting the mic element and the PTT switch. Al might want to use shielded cable for the mic if the waterfall policeman on 40 meters detect RF feedback and freak out.

The CHIME Radio Telescope and Fast Radio Bursts

The new Canadian radio telescope is very interesting. It has a great name for a radio telescope: CHIME

And it it always nice to come across a reference to the Parkes Radio Telescope.

More info here:

https://www.theregister.co.uk/2018/08/03/fast_radio_burst/

And here:

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

Good luck on getting a QSL from the FRB station.

WA4GEG’s Beautiful HB Transceiver

http://www.hamradiobug.com/homebrew.html

Pete spotted this. Beautiful work. I noted that Byron hasn’t used the Manhattan style of construction. This makes his work look a lot neater, but it makes it harder to modify and debug the circuitry. On the other hand, OM Byron is obviously so good at this that his circuitry probably doesn’t require any debugging or mods.

The red S-meter and freq counter give it a slightly menacing appearance. Very cool.

Wow. Mr. Carlson’s New Old-Time Radio and Test Gear Lab. VE7ZWZ — Homebrew Hero

It has been a while since we last visited Mr. Carlson’s lab. As always, we found it amazing. The awesomeness just keeps increasing. Previous visits: https://soldersmoke.blogspot.com/search?q=Carlson

As was the case before, this is really almost too much. THREE DX-100s in the shelves. A massive collection of tubes, some sorted, some un-sorted. But don’t worry — Paul has a good memory and remembers where everything is. I believe him.

For his amazing shack and workshop(s) and for his willingness to repair old-time test gear, Paul VE7ZWZ clearly deserves homebrew hero status.

Thanks Paul.

A Rig with Maximum Soul: The 5 Band Transceiver of Glenn KU4NO

That’s the front panel. Glenn’s kids and grand kids liked sitting on his lap while he played radio and putting stickers on it

This is one of the best HB2HB contacts I’ve had. I was just getting ready to sign off on 40 meters when I heard someone calling me. It was KU4NO. I thought I’d just give the OM a quick report. Then he said, “My rig is homebrew too.” And wow, it is indeed! When he said this my first thought was that maybe this was a kit rig, but no, it turns out that this rig is the scratchyist of scratch-built rigs — true hardcore hardrock homebrew.

I checked my log. I had worked Glenn once before, in December 2001. I was in the Azores. And he was using this same rig. Glenn told me that for all these years, this has been his ONLY rig. A friend gave him a modern commercial rig, but he prefers this one. I understand completely.

At first, Glenn made me promise not to share the pictures with anyone. He seemed a bit embarrassed by his creation. I told him that SolderSmoke readers would appreciate his rig and see the value of it. I explained that we all have soldering iron scars on our fingers, and clothing that has been stained by ferric chloride. We LIKE ugly. It took some persuasion, but I got him to agree to let me share this with the group.

Glenn reports it is based on a “5 band transceiver” circuit in the 1976 or 1977 handbook. (i don’t have one and can’t find it on-line — can anyone get us a copy of the schematic and article?)

So I say THREE CHEERS for Glenn KU4NO and his homebrew 5 band transceiver. For me, the stickers are the most important feature of this rig. Please e-mail me your comments on Glenn’s rig – in an effort to let him know how much we appreciate and understand his effort, I will pass them on to him. I wish more hams would follow his example.

Glenn wrote:

Oh well I’m not too concerned about who sees it.
I just wouldn’t want to cause anyone to follow my example.
Maybe you could call it “a tornado goes through a junkyard.”
Just kidding around …no restrictions…I’m sure it will be forgotten soon ….. but I will be innocent of any harm caused by it.
Its the only rig I’ve ever owned when we contacted before it was with it.

The inspiration article in the 76 or 77 handbook is worth a look.
The VFO tuning cap and mount came from a CB “slider” one of my brother-in-laws gave me it seems to work well
Glenn
Picture Above: top view upper left power out two IRF 510s from w2eby ( I think) 30+ to 60+ watts across HF love this circuit, small board connected at right angle is 1/2 watt driver from Harrys Homebrew page 2n2222 driving 4 2n2222s beautiful circuit
lower left power transformer
one of two wafer band switches in middle …. under wafer switch is hf mixer and single balanced mixer to generate ssb
LO from progressive receiver top right … heat sink just to left and lower unused voltage regulator
RF amp and wafer switch lower right used for transmit and receive

LO tuning cap and hf mixer modulator circuit

RF amp

Crystals for mixing, BFO, old detector circuit. Old circuit that repeated CQ call, chip from Radio Shack

Some micro relays …… audio amp at bottom and two switchable compressor circuits one using an SL 1626 and one lifted from a President model CB radio and some filter caps
New IF AGC audio detector uses three ca 3028As from 67 handbook schematic is wrong can you find the mistakes? it was printed wrong twice i use an s meter with it

Close up of power output and lower left rf output filters

Homebrew Juju — HB2HB

Oh man, last night the Radio Gods were on my side. I only had about a half hour on 40 SSB, but I had some really nice QSOs. WB2HJK George in NYC was very interested in the BITX revolution. W3BT in Philadelphia is a kind-hearted OT who ran an ENORMOUS Yagi atop a row-house in the city — the antenna extended over the street and TWO of his neighbors houses. Never had a TVI problems. FB. SS listener WA3O Mike called in — Mike is the fellow who gave me my HW-7. Mike has been running his uBITX into a homebrew 500 watt LDMOS amp. FB Mike.

Then the real miracle happened. Just as I was about to throw the switch, Glenn KU4NO called. I decided to give him a report. But then he said something I rarely hear: “My rig is homebrew too!” I checked the log — I had spoken to Glenn before, but our last QSO was in December 2001. I was in the Azores. Glenn was on the same homebrew rig. We had a nice talk about his rig. FB.

Glenn told me that in all his years on the air, he has only had a few contacts with other homebrew stations. He had a list of them: 1) W4ZCB, 2) N6ORS (FB! SS Listener!), N2CQR (“No wait — I just heard you but we didn’t talk.”) and W2JUQ. I will tell Glenn that he needs to add CU2JL to the list — that was me in 2001 and I was indeed homebrew DSB.)

To top it all off, Dino KL0S was listening and recorded the final part of the QSO. See below. (The video might take a few minutes to load.)

In honor of that FB night on 40 I am re-posting the animated GIF of my BITX-17 build. I hope it doesn’t make you seasick!

Also, I think we need to add a term to the SolderSmoke lexicon: Juju. As in Homebrew Juju. See: https://en.wikipedia.org/wiki/Juju Right? What do you think Steve Silverman?



Homebrew Tuner for Doublet Antenna


For now, I’ve put the Moxon project on the back burner. I will take it up again once Old Sol starts showing some spots. In its place a 135 foot doublet is going up. I got at a hamfest a while back. (It is the only HF antenna that I ever bought!) It is the SPI-RO Manufacturing Company’s Model A-10. It came with 100 feet of 450 ohm window line. It will be up on the roof soon.

Today I put the tuner on the wall in the car port right outside the shack. I even built a little shelf for the SWR meter (used one of those Whole Food grilling planks!). I put a 25 ohm resistor where the feed line will connect. I was able to tune it up on the two bands I tried: 40 and 17.

There is a smaller coil inside the big one — the smaller coil resonates with the lower variable cap.

You can see all the homebrew rigs in the background — waiting patiently for the antenna.

I actually built the tuner back in 2012, but never used it. Description here:

https://soldersmoke.blogspot.com/2012/01/2012-off-to-good-start-balanced-atu.html
I will try to provide a schematic and more details soon.