Bonner County Amateur Radio Club – K7JEP

Bonner County Amateur Radio Club - K7JEP

K7JEP: In memory of Neal Fredstrom 1931-2003

Homebrewing

Gary H White – K2KKB

I have been accused of being a “tinkerer”, some even saying “Tinker” ought to be my nickname.  So, needless to say Homebrewing holds a special place for me (as you will no doubt gather from the following).

Just what is homebrewing?

Unlike the name sounds “homebrewing” is not about making your own alcoholic beverages.  Homebrewing is an amateur radio slang term for home-built, noncommercial radio equipment.  Homebrewing differs from kit-building in that the home brewer is not supplied with a predesigned project which has all the necessary parts and which has been extensively tested by the manufacturer.  The home brewer usually creates equipment using parts and designs of their own, or modifying plans (schematics) of others, to construct their project from parts gathered from varied and often improvised sources.

Homebrewing is valued by amateur radio hobbyists, hereafter called “Hams”, for its educational value, to allow experimentation and development of techniques or levels of performance not readily available in commercial products, or to meet a specific need.  Some items can even be home-brewed for a similar or lower cost than purchased equipment and many times will incorporate additional features.

For the ham, homebrewing can take many forms.  In today’s world, as I see it, there are four separate but somewhat inter-related groups to which Amateur Radio is of interest. The “preppers” (many of which only want the ability of communication as a back-up and have no further interest in the hobby), the EMC (ARES/RACES) people that truly want to serve their communities in emergencies, those that enjoy the ability to communicate worldwide and only want the basic understanding to do so, and last, those looking to truly understand today’s electronics in order to make, experiment, and evaluate equipment and ideas in light of today’s technology.  Homebrewing addresses the later.

A large portion of today’s home brewing is related to QRP projects (low power, usually less than 5 watts output) and building antennas.  However, that has not always been the case.  In the early days of amateur radio before commercial equipment was easily available most hams out of necessity built their own transmitting, receiving, and station equipment.  In the 1930s, 40s, and 50s, hams handcrafted vacuum tube transmitters and receivers of acceptable performance which were often housed in their basements, and it was common for a well-built “homebrew rig” to cover all the high frequency bands (1.8 to 30 MHz). 

In the 1950s and 60s, many hams began constructing their stations from kits sold by Heathkit, Eico, EF Johnson, Allied Radio’s Knight-Kit, World Radio Laboratories and other suppliers or by purchasing and modifying readily available military surplus units.  Today, only a minority of hams own and operate completely homebrew or kit-built amateur stations.

There are still many kit suppliers, and the “art” of homebrewing is alive and thriving.  But even the most skilled home brewer may not have the time or resources to build the equivalent of modern commercially made ham gear from scratch, as the commercial units contain custom integrated circuits, custom cabinets, and are the end result of multiple prototypes and exhaustive testing.  However, constructing a Ham’s own equipment using relatively simple designs and easily obtainable or junk box electronic components is still possible and with an understanding of circuits and modern components, it is still possible to create virtually anything required by a ham.  Homebrew enthusiasts say that building their own radio equipment is fun, educational, and gives them the satisfaction that comes from mastering electronic knowledge.

Antenna homebrewing is one of the more popular activities.  The internet and ARRL publications abound with articles and books.  They cover about anything a Ham could want to know to create their own antenna.  And, with the proper understanding and attention to detail, these antennas achieve equal, or even surpass, commercial equivalents in their performance.  (See the antenna section for more information)

QRPers are ham radio enthusiasts known to use a power output of five watts or less, sometimes operating with as little as 100 milliwatts or even less.  Commercial transceivers designed to operate at or near QRP power levels have been available for several years, but many QRPers prefer to design and build their own equipment, either from kits or from scratch. Some have built miniature transmitters and transceivers into Altoids boxes and operate using battery power. Popular QRP kit models include the Elecraft K2, KX1, and now KX3 and those produced by NorCal, Small Wonder Labs, and others. QRP activity can often be heard on 7.030 MHz

“Glowbug” is a term used by US amateurs to describe a simple home-made tube-type radio set, reminiscent of the shortwave radio-building craze of the 1920s and 30s.  Generally, any home-built tube-type transmitter or receiver may be referred to as a glowbug.  The majority of glowbug transmitters are designed to be used in the CW mode.   A number of Hams also build their own tube receivers and AM voice transmitters.

As late as the 1960s, glowbugs were part of many beginner ham stations because of their simple, tube-based designs.  Glowbugs are popular among QRP enthusiasts and others with a penchant for constructing their own equipment.  Enthusiasts may assemble glowbugs on steel chassis, tin cake pans, and wooden boards.  Glowbug enthusiasts can often be heard communicating on the shortwave bands using Morse code.  Simple oscillators for this frequency can be built with common NTSC color burst oscillator crystals, which operate at 3.5795 MHz

The above just scratches the surface of the possibilities available to the home brewer.

Is Homebrewing Worth the Effort?

Is homebrewing dead?  Is it worth the effort?  No doubt homebrewing has changed from the 1940-60’s when Hams built virtually every piece of equipment in their station.  But I submit that homebrewing is still alive and well as evidenced by the ever increasing popularity of Arduino projects that can be found on the internet and articles in such publications as Nuts & Volts & QST.  There are still those looking to truly understand today’s electronics in order to make, experiment, and evaluate equipment and ideas in light of today’s technology. 

I think that many people forget that by the 1940-50’s we were only in our first 100 years of truly understanding electricity much less wave propagation. With that said, the Ham Community has always been in the forefront of the exploration and innovations of this fascinating hobby.  Those that lead the way were always willing to bring people into their “shop” and tutor them in the basics of electronics and repair as they knew it.  They were not PhD’s in math or science.  Most of what they knew came from “trial and error” experimentation and collaboration with each other.

However, in the 1970’s Ham Radio changed with the introduction of semiconductors.  The components changed and required a slightly altered mindset, but the underlying principles were still the same.  With the introduction of the microprocessor homebrewing became much more difficult.  Technology advanced to surface mount ICs, multi-layered PCBs, ball grid arrays, wider bandwidths and operating frequencies.  Many hams couldn’t afford the fabrication and test equipment or just failed to stay up to date.

 We no longer repair electronic equipment.   And, if a person can or is found that is capable of doing so, the cost is usually prohibitive.  If it goes bad, we throw it away and get a new and better one for less money.

Because of the above, the ham has been relegated to buying their equipment, experimenting with antennas, high power amplifiers, satellites, TV, microwaves, new digital transmission modes, and QRP.  Most of which requires an in-depth understanding of modern technology.

My point to the above is two-fold. 

1st: Because of the advances in technology, many hams no longer understand the basics of the equipment they operate.  There’s a paradigm shift going on in Ham Radio.  A growing number of hams are now “appliance operators”.   Most of them haven’t even looked at the block diagram of the equipment they run and a sizable proportion of those wouldn’t know what they were looking at anyhow.   For instance – what is/was the purpose of “grid-dipping”?  Does it have any relevance today?  (The exam question seeks an answer based in its effect, max output, but not why.)  By not understanding the principles behind a particular circuit or piece of equipment the ham may discard, sell, throw away, or misuse an item due to their own misapplication.  In too many instances understanding at the basic level has been relegated to the professional EE. 

 And, 2nd: Again, because of the advances in technology, hams can no longer think just at the component level but must also think at the systems level when designing.  Homebrewing actually brings people up to date with the use of modern technology through experimentation.  There are many devices (IC’s) readily available to the ham at a relatively low cost, that once they learn how to work with these, would allow them to build just about anything they need to enhance their knowledge and equipment.  I think that is one of the reasons for the popularity of the Arduino groups.  One commenter sarcastically stated, “Basically we have traded the soldering iron for a programming language”.

Homebrewing today has increasingly become a “board level” endeavor and there is an ever decreasing need for discrete component level fabrication.  Is this really that much of a leap from the way that homebrewing was being done in years past? Especially when you consider that from the 1930’s through today very few people actually fabricated their own vacuum tubes, capacitors, resistors, diodes, or any of the various other components.   But at some point in history people did have to build all of these discrete components for themselves.  When these components became commercially available, home brewers didn’t throw up their hands in frustration and proclaimed that they couldn’t build anything anymore because the technology had past them by.   Instead they just adapted to this newer but higher level of homebrewing.  You can still do a lot of homebrewing, but now it is by using more prefabricated boards along with software and fewer discrete components than in the past.

 Homebrew is not dead…….when we choose not to challenge ourselves any longer it WILL die.   Like everything else in life, it’s constantly changing, evolving.

So, in summary,

If you want to truly understand today’s electronics in order to make, experiment, and evaluate equipment and ideas in light of today’s technology, then yes, homebrewing is worth the effort. 

The ability to build and use our projects on the air is what separates ham radio from all other hobbies.

Where do you start?

At this point you may be asking, “What skills do I need and where do I start?”

The skills required for homebrewing are like everything else you have done in your life.  You need:

  1. Curiosity
  2. Desire to learn
  3. A sense of humor
  4. The ability to use Google or other search engines will be of immense help
  5. Willingness to ask for help

You were smart enough to get a license and you just may know more than you think you do. 

You were actually introduced to homebrewing basics when you studied for your ham license.  You were introduced to the basic passive components and to schematics, now you will take them to a new level.  While I have not studied for my Extra Class license, it seems like you will gain an added benefit.  From what little I have delved into the Extra license, it seems you will also be preparing to take the Extra exam as it goes much deeper into circuit basics.

As you progress an understanding circuits, components, and reading of schematics will be necessary.  Do you need to start from scratch or, like me after a 40 year lay-off, need a good in-depth review and updating your understanding of modern techniques?  I have not found any truly self-guided curriculum for studying electronics on the internet.  So the following will be what I have learned so far.

A good book to learn schematics, or brush up, is the “Beginner’s Guide to Reading Schematics, 4th ed., by Stan Gibilisco”.  It is readily available and affordable from such places Abe’s Books in used condition and can be downloaded for free at several sites on the internet.

I recently re-discovered the ARRL Handbook for Radio Communications.  For a self-paced curriculum geared to the Ham, I have found nothing better.  This does not have to be the latest and greatest edition.  Circuit basics, components, and how they are put together, like building blocks, hasn’t changed a lot in the last 40-50 years.  Now most of that is being done with IC’s but you still need the understanding of the circuits.  I bought the 2010 edition, still in the cellophane for $10 and will buy newer editions when I find them in bookstores or hamfests if I find they delve deeper into homebrewing with modern IC’s.

So, my advice is, if you think homebrewing may be for you:

  1. Experiment: failure is annoying but if you figure out why it failed your ahead. Building is generally about learning not necessarily cost saving.
  2. Start with easy projects. Obtain a few components and breadboards and build simple circuits like oscillators and filters. There are only 3 basic circuits to learn and 7 commonly used components.
    • Rectifier, Amplifier, Oscillator Circuits
    • Resistor, Capacitor, Coil (or Inductance), Transformer, Switch, Diode, and Vacuum Tube/Solid State components.
    • All circuits are a combination of or variations of these circuits.
    • Learn these circuits and how the components effect that circuit and you will know 80% of what you need to understand any circuit.
  3. Start with basic tools (pliers, side cutters, screwdrivers) and equipment (VOM, soldering iron, etc.) and add/build as your understanding and needs grow.
  4. Build anything you care to and use any technique that’s available to you and suitable for the project. As you progress look at commercial equipment and see if it can be enhanced. Such as building a dummy load that will also allow you to check a transceiver’s fold back by adding a 3:1 or 4:1SWR mismatch or a watt meter to check output.
  5. There are many more items used by today’s hams than transceivers. There are plans and kits for just about anything else found in today’s ham shack–like digital clocks, antennas, antenna analyzers and SWR meters, power supplies, test equipment, interconnection electronics between transceivers and other electronics such as computers, packet modems, GPS units…….and the list goes on and on.

The added benefits are:

  1. You are using equipment made by you that truly fits your needs (it may not be as pretty or as small).
  2. You are better able to troubleshoot your own equipment
  3. You will be fully capable of creating your own equipment if there is not a commercial product available (for example, it is fairly easy to make your own heat sinks with some casting sand and scrape aluminum)
  4. You are better able to evaluate any commercial product you are considering purchasing.