Listen to Latest SolderSmoke Podcast

Sunday, August 19, 2018

"From Crystal Sets to Sideband" -- Homebrew Wisdom from Frank, K0IYE (Free Book)

Get Frank's book here (FREE!)

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 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. 


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!)
THANKS FRANK!      Send Frank a thank you note: 

Saturday, August 18, 2018

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.  

Sunday, August 12, 2018

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 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 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  

Tuesday, August 7, 2018

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 
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 

Monday, August 6, 2018

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. 

Sunday, August 5, 2018

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:

And here:

Good luck on getting a QSL from the FRB station.

Saturday, August 4, 2018

WA4GEG's Beautiful HB Transceiver

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