My second HecKits build was a great experience – just like my first!
I have become a big fan of the HecKits QRP kit line. A few months back, while looking for a modern dip meter kit, I discovered HecKits and ordered their FET Dip Meter. My experience was with that first kit was great in every way. I was impressed by the high quality of the materials and components, the easy to follow directions, the excellent documentation, and the outstanding customer support courtesy of Darrel Heckendorf, the man behind HecKits.
My wife gifted me the HecKits QRP mW meter as a birthday gift this year and I had the time this past weekend to tackle the project.
Once again, HecKits gets the highest marks for its documentation. The construction manual, sent by PDF by Darrel, was comprehensive, easy to follow and full of detailed illustrations. And again, I was very impressed with the high quality of the parts and materials included in the kit. Everything needed to complete the project is included and the fit and finish is unparalleled.
I was very impressed with the screen printed plated through PCB and included in the kit is a handsome precision drilled metal enclosure giving the finished project a professional appearance. While building the meter, I frequently paused to appreciate the high attention to detail that was put into the kit. For example, the manner in which the BNC connectors mate with the PCB and back panel of the enclosure shows precision engineering that went into developing the kit.
I was able to assemble the kit from start to finish in about three hours’ time – and I do work slowly and try to be meticulous in my work. The meter requires the builder to wind two toroids – a task that I never mind – and again the detailed directions would make it nearly impossible for even a novice builder to fail.
I did run into a small glitch, however. When I finished assembling the kit and began the calibration process, I was disappointed to find that the meter was not responding when I first applied power.
I removed the PCB from the chassis to begin troubleshooting. I had assumed perhaps I messed up the polarity on a diode or tantalum capacitor, but quickly discovered the problem was the ham-fisted way I inserted one of the ICs into the DIP socket, smooshing one side of the pins against the socket. I carefully straightened the pins, reinserted the chip and VOILA! All was well.
HecKits gets big props for the calibration process too. All that is required is a precision voltmeter and an RF tuning tool or eyeglass screwdriver. The kit has a multi-turn pot on the PCB that is used to adjust input voltage for calibration purposes. Once the builder sets the input voltage to the specification, the meter is adjusted for full deflection at 10 watts, 1 watt and 100 milliwatts by adjusting the corresponding trimmer pot on the PCB. What a snap!
I’m eager to add my new wattmeter to my QRP station and I look forward to my next HecKits build. You can get your own HecKits QRP meter or one of their other fine kits on their website – https://heckits.com/shop-heckits. I highly recommend their products for anyone who enjoys building their own QRP gear.
Have you built a HecKits kit? What was your experience? Please leave a comment or drop me a line at email@example.com.
Thanks for taking the time to visit my blog! 72 de AB1DQ / James
This August I picked up a pair of Heathkit HD-16 Code Practice Oscillators for $10 at the flea market at the ARRL New England HamXposition in Marlboro, Massachusetts. The CPOs were tech-specials, non-functional, but ‘mostly there’ with only a few missing parts.
BEFORE: What $10 will buy you at a ham radio flea market.
The HD-16 was Heathkit’s second code practice oscillator, introduced in 1974 and following the first Heath CPO, the CO-1 which was first sold in 1959. The HD-16 was sold until 1974, replaced by the HD-1416 in 1975 which sold with a few cosmetic variations until 1990.
Up until the turn of the century, prospective hams needed to demonstrate the ability to copy and send Morse Code at 5 words per minute (WPM) along with passing the written practical exam to earn the entry level Novice Class license. Advancing to higher class license classes required the upgrading ham to demonstrate the ability to send and receive code at faster speeds – 13 WPM for the General license and 20 WPM for the Amateur Extra Class.
In 1999 the FCC eliminated the 13 and 20 WPM upgrade exam requirements requiring hams to only demonstrate an ability to send and receive code at 5 WPM for high frequency privileges. Then, in 2006, the FCC eliminated all Morse Code testing altogether in accordance with the worldwide policy change the International Telecommunication Union made in 2003,authorizing each member country to determine whether or not to require individuals to demonstrate Morse code proficiency for licensing.
Despite the fact that hams no longer have to demonstrate the ability to copy and send Morse Code, operating CW or Continuous Wave with code remains as popular as ever in amateur radio. Many hams today choose to learn the code and many of us (yours truly included – a ham who only needed to pass a 5 WPM exam back in 2002), very much enjoy ‘pounding brass.’
Thus, the code practice oscillator, or CPO for short, was and remains a very useful piece of equipment for any ham aspiring ham to operate using Morse Code.
My Restoration Project
I began by disassembling both units completely and saving the screws, nuts and other hardware in (what else?) a cigar box in order not to lose any original parts.
The guts of both CPOs liberated from their cabinets.
I washed the cabinet parts in warm water and dish soap and gently scrubbed away at the stains with a soft brush. The back halves of both cabinets were scuffed and scratched badly so I chose to re-paint them in flat black.
Purists would only use the signature Heathkit dark green paint, but I didn’t have any on hand and, while I appreciate complete restorations of antiques, my philosophy for repairing old radio gear has always been to take advantage of what is available to make the vintage equipment usable to me today.
After sanding the enclosure backs with a fine grit sandpaper I applied 3 thin coats of flat black paint and then coated all pieces with 2 coats of clear coat. To compliment the blacked out cabinet sides, I also painted the speaker grilles with flat black paint and replaced the enclosure screws with new black screws.
On to the electronics
I found the original HD-16 manual online and printed a copy for reference. Like all Heathkit manuals, the HD-16’s was well written and included the schematic, complete specs, and some nice content on circuit theory and Morse Code.
Heahtkit HD-16 schematic from the original manual.
From the original Heath manual…
The unijunction transistor, Q1, is a special type of semi-conductor device, with two bases and one emitter, which acts as a relaxation oscillator in the following manner: When the key is closed, capacitor C2 is charged by the battery voltage through resistor R1 and the Tone control until the Emitter (E) voltage reaches the point at which the Emitter is forward biased with respect to B2.
Emitter current then flows because the dynamic resistance between the the Emitter and base one (B1) then drops to a low value. R2 drops the battery voltage to a low level, permitting C1 to charge to a higher voltage than B2.
Capacitor C1 discharges through the Emitter and Volume control until the voltage at the Emitter drops to the point where the Emitter is no longer biased. The cycle then repeats itself at a rate governed by the setting of the Tone control.
The pulsating base current, or oscillator signal, is developed across the Volume control. From the arm of the Volume control, the signal is coupled through the normally closed contacts of the phones jack to the speaker.
The lamp circuit uses the key as a switch that makes and breaks the C cell battery voltage to the lamp.
On Unijunction Transistors
When I first glanced at the HD-16 schematic, I didn’t notice that the transistor was neither a familiar BJT or a FET. Upon closer study I noticed that Q1 is a “unijunction” transistor and was labeled with two bases, B1 & B2 and an Emitter, E.
Schematic symbols for the UJT: N-type on left, P-type on right
My immediate concerns were how rare the 4JX5E670 is, and whether they or a solid equivalent can be found at a fair price today should I need to replace them. My concerns were tempered however by the excitement that this project is going to afford me the opportunity to learn something new.
Up to this point in my life, I have had a cursory knowledge of transistors. I knew the difference between NPN and PNP Bipolar Junction Transistors – their construction and function – and I had a very basic understanding of how a Field Effect Transistor differed from a BJT.
Doing a little Googling, I learned that UJTs could only function as a switch and not as an amplifier. This made sense as the ability to generate pulses would be key to function as an oscillator at the heart of the HD-16.
Structure of a P-type UJT (source: Wikipedia)
Back to the project… assessing the damage.
At first glance, one HD-16 was missing its lamp and the C cell battery holder. The C cell battery holder in the other HD-16 was extremely corroded. Also missing were three of the four 9 volt snaps. One of the 10K tone potentiometers was gunked up and the shaft would not turn. Otherwise, everything else appeared to be present…. not bad.
I grabbed a 10K pot from my on hand parts stock and replaced the seized control and I soaked the other pots as well as the switches with de-oxit and worked the contacts.
I decided to replace the 0.22 uF capacitors with a pair of new Mylar caps from my stock. I did not test the fixed resistors and I didn’t even bother to check to see whether I had any 4JX5E670 UJTs in my parts supply. I would dive deeper and replace any of these parts if the oscillators failed after the other work I did.
I debated whether to replace the lamps with LEDs, a popular and logical mod. Doing so meant I could eliminate the 1.5 volt batteries altogether and complete the mod by adding a dropping resistor from the 9V batteries and rewiring the SPDT switch.
I liked the way the original incandescent dial lamp looked so I didn’t do a mod for LEDs. Since I needed to replace one of the missing C cell holders and the remaining one was badly corroded, I replaced both with modern plastic holders. I attached the new holders to the inside of the cabinets using 3M 2 sided tape.
I was unable to determine whether the HD-16 was a DIY kit or was sold only as a completed unit as I couldn’t find a construction manual online. So I took the time to sketch out the schematic and trace the parts layout creating a pictorial diagram I could use to confirm the circuit was complete.
Putting it all together
I worked on both oscillators side by side, working through each step of the restorations on one unit, then the other. It made sense to work this way as I could stay focused on each step as I worked.
After completing the parts replacement I grabbed some batteries and tested each HD-16 before attempting reassembling. Fingers crossed, both worked fine and I was relieved I didn’t have to address replacing the unobtainium transistors.
One of the completed electronic restorations – ready for testing and reassembly.
Reassembly went smoothly. I started by replacing the lamp grommet and inserting the lamps into their holes on the top of the enclosures and then installing the speakers and grilles.
Next I reattached the springs on the backs of the cabinets – this was Heathkit’s clever idea to secure the 9 volt batteries securely in place – and I stuck the new C cell holders onto the back of the enclosure using 3M double sided tape.
Next I installed the switches, confirming that they were properly oriented to light the lamp when set to “LIGHT,” and then I re-inserted the two potentiometers and the key and phones jacks to the front panel.
The last thing I did before closing up the cabinet was to secure the terminal strip to one of the speaker screws. The space available was tight, but not impossible. I took special care to make sure that the transistor and other component leads weren’t shorting out against each other. I did another test of both units before closing up the cabinets.
Both HD-16 cabinets ‘re-stuffed’ and ready for buttoning up.
Both HD-16s had the original metal foil serial number sticker stuck inside the cabinets, but they were in bad shape and not salvageable. So I created a “new-retro” style serial number sticker for each unit in order to preserve each CPO’s history.
AFTER: Two restored Heathkit HD-16 Code Oscillators ready for use!
Do you or did you have a Heathkit Code Practice Oscillator? If so, which model and how did you like it? Comments and questions encouraged. Drop me a line at firstname.lastname@example.org to join the conversation!
A fun, easy-to-build, weekend radio kit project that is the latest to get the AB1DQ Cigar-Box treatment.
It’s no secret that as a modern day electronics kit builder, I have a fondness for the fine kits currently being offered by the Four State QRP Group and it’s also no secret that one of the biggest gateways to my ham radio ticket was the years I spent as a SWL in my teen years.
Is it any surprise then, that I would at some point build the 4SQRP Group’s excellent long-running Ozark Patrol Shortwave Receiver? Quoting, their website,
…this kit was designed in homage to simple beginners regenerative receivers of a generation ago. Many current hams and radio enthusiasts were introduced to the hobby by building and listening to such classics as the Radio Shack Globe Patrol, or the Knight Ocean Hopper. … the Ozark Patrol is offered so that the builder of today can relive the excitement of tuning in the world on a simple receiver circuit.
Once again, you’re singing my song 4SQRP – count me in!
About the Kit
While still an undergrad at Columbia University, legendary radio pioneer Edwin Armstrong patented the regenerative receiver in 1914 and it was leaps and bounds ahead of the then state-of-the-art receiver circuit.
By applying some of the output signal from a vacuum tube back into the input signal in phase, a feedback loop is created that greatly amplifies the signal by as much as 1,700 times. A regeneration control is used to gradually adjust the amount of feedback to the point of oscillation where the signal will distort. The regenerative receiver features improved sensitivity and selectivity over other receiver designs of its day.
The Ozark Patrol circuit, designed by David Cripe, NM0S, replaces the vacuum tube of Armstrong’s era with a common NPN bipolar transistor. The kit has only 38 through-hole components for the kit builder to attach making for a build time for me of under two hours.
The Ozark Patrol also features the modified surface mount technique known as the “Pittsburgh Method” of construction, pioneered by Joe Porter, WØMQY. Leaded components are directly soldered to pads on the back copper layer of the circuit board (which also makes the front panel of the radio), forming a ground plane to shield the radio from hand capacitance effects while tuning.
I previously built the 4SQRP Murania one transistor “Boy’s Radio” kit that used the Pittsburgh Method and it was a positive experience. You can read about that build here.
Building the Ozark Patrol
I built the kit in under three hour’s time over a couple of days. As I’ve come to expect from 4SQRP, the kit was well packaged, complete and not missing any parts, and the step by step instructions were for the most part very clear and easy to follow. A couple of times I did find myself referring to photos of others’ builds for clarity – particularly when working with the tuning capacitor and the ‘gimmick capacitor.’
The kit requires the builder to wind a single toroid inductor, 20 turns on a T-50-2 core and its the first step of assembly. Because I started my build in the evening after a long work day, I chose to wind the toroid later when I was feeling 100% fresh, and instead started my build by attaching the resistors, diodes and fixed capacitors.
A novelty feature of this kit is that it requires the builder to wind a ‘gimmick capacitor’ to couple the antenna to the tuning capacitor. This low value capacitor is easily made by twisting about an inch of magnet wire with insulated hook up wire. I had no difficulty doing this, and I apparently did it correctly as my receiver worked the first time.
The instructions suggest that the radio can be made or less selective by tightening or loosening the twist so I may choose to experiment with this. Fellow kit builder and blogger, Mike Simpson, has a really great post about his build of the Ozark Patrol here in which he describes his mod adding a varicap in lieu of the gimmick cap for coupling and tuning the antenna. Check it out!
The Cigar Box Treatment
The Ozark Patrol comes with a slab of soft pine wood which is intended to be used as a base. The circuit board/front panel is screwed to the board at 90 degrees leaving the guts exposed for viewing and the easy attachment of the antenna and ground wires.
I initially envisioned mounting the radio on the top or the bottom of a cigar box and attaching a handle to fashion a finished radio resembling a portable transistor radio of my childhood years.
Looking through my stash of cigar boxes I found an Oliva box with a hinged lid that had almost the exact dimensions of the Ozark Patrol circuit board. What good fortune!
Using a box cutter, I carefully pried off the bottom of the box and then smoothed the edges, removing excess dried glue with a fine grit sandpaper.
The location of the screw holes on the circuit board unfortunately were spaced to fall just inside the edges of the cigar box sides. I addressed this by adding square dowel reinforcements to the four inside corners of the box using wood glue. Once dried and set, the dowels provided both a space to drill pilot holes for the PCB screws and reinforcement for the box itself.
Finishing touches included using brass thumb screw hardware mounted to the side of the box for retro- looking antenna and ground terminals and attaching a decorative drawer pull to the top to provide a carrying handle.
Inside, I attached the 6 AA battery holder to the box lid, making sure that I left sufficient slack in the leads for the lid to open completely. I also cemented a copy of the schematic inside the lid. In the end I have a very retro- looking suitcase shortwave radio that has a bit of resemblance to portable radios like the Zenith Trans-Oceanics of an era gone by.
How did it work?
Last night I set the radio up in a second floor bedroom, attaching a ground wire running to the ground lead of a power outlet and a random length of wire for an antenna suspended to the light fixture. I also shut off the LED room lights which made a difference in lowering noise.
Tuning the radio was definitely a fiddly process, but it was also a ton of fun. I easily picked up 3 or 4 AM shortwave broadcasters on one band and hams operating CW (Morse Code) on the other. Success!
I would highly recommend the Ozark Patrol kit for any kit builder, or aspiring kit builder. The kit shouldn’t present too much of a challenge for even a new kit builder and the finished radio works and is fun to operate.
Have you built the Ozark Patrol or a similar kit? Perhaps you built the Radio Shack Globe Patrol back in the day? Please leave a comment or drop me a line at email@example.com to share your experience!
“Creativity is inventing, experimenting, growing, taking risks, breaking rules, making mistakes and having fun.” ~Mary Lou Clark
Ham radio is unlike and superior to all other hobby radio services as it not only allows licensed operators to build, test and experiment with our radios and other equipment, we are encouraged to do so.
Long before I earned my ham radio license, I’d spend hours on end as a child creating various projects fueled by my imagination, using the never ending supply of empty cardboard Dexter cigar boxes my grandfather had stashed in our basement.
Several of my creations in my early adolescence involved radio & electronics projects. Besides providing me with a stash of cigar boxes to play with, my grandfather also had a fairly complete electronics workbench in our basement, complete with tools, tubes, parts, dozens of radio & TV carcasses in various states of disrepair and a treasure trove of 1960s era magazines including such titles as Pop Electronics. My grandfather had also taken the DeVry Home Radio & Television course before I was born and to my delight, all of his workbooks and home projects were under the workbench.
As a licensed ham radio operator for the last 20 years, one of my favorite aspects of our hobby is kit and scratch building and operating with QRP gear I’ve built myself. Over the years I’ve built projects into aluminum chassis, atop breadboards, in tuna tins and even tiny mint cans. Following in my grandfather’s footsteps in yet another way, I’ve become something of a cigar aficionado in recent years and found myself amassing my own stash of cigar boxes. It wasn’t too long before inspiration struck and I put one and one together.
Why the Cigar Box Chassis?
My cigar box fascination blends two of my leisure loves – radio & cigars. It also gives me the opportunity to challenge my creativity and express myself through unique projects. Building with cigar boxes also connects me to my childhood roots, per above, as well as the very roots of amateur radio, taking me back to the early era of breadboarding. Finally point-to-point construction using terminal strips and increasingly rare leaded components is not only ‘going retro,’ it’s also a lot easier on us older folks. While the parts got smaller, our vision got weaker and our hands a bit shakier!
There are several advantages a cigar box chassis brings to your project, such as:
adding flair & artistic touch to the project,
being available in different sizes and shapes,
being much easier to drill and cut than metal chassis,
being easily oriented in various ways to accommodate specific project needs.
having multiple construction planes – the top & bottom of lid, and the bottom of box.
providing space to store cables, accessories, and documentation inside the box.
Conversely, there are a few disadvantages to be aware of when building a project into a cigar box, such as:
varying quality of construction,
cheaper flimsy boxes may be difficult to drill and cut cleanly,
boxes with thicker lids and sides, make the mounting of some parts difficult,
lacking the inherent shielding and common ground plane of a metal chassis,
hinged lids may make for challenging parts placement and wire routing.
“The creative adult is the child who survived.” ~Ursula Le Guin
There are several contemporary kits that I became aware of that helped spark my imagination for my cigar box builds. These included the very fine line of Peebles Originals kits which featured point-to-point construction on a wooden base. I had build a few of the Peebles kits including a one tube regen receiver I built with my 12 year old niece a few years ago.
My good friend, and radio cuckoo soulmate, W1YSM, Dr. Ed Snyder, gave me a wonderful gift a few years ago, the Thames & Kosmo Radio Ace, a mid-2000s one tube regen BCB & SW receiver ‘kit’ built into a nicely finished wooden base. This wonderful kit didn’t require assembly but came with a wonderful step-by-step book explaining how radio and this specific circuit works.
Inspiration also came from the Four State QRP Group’s venerable Bayou Jumper QRP transceiver kit, which is a scaled down solid state replica of a WW2 era ‘paraset‘ rig. The kit is intended to be built into a wooden suitcase box.
Sources of inspiration from L-R: a Peebles Original 1 tube regenerative receiver, the 4SQRP Bayou Jumper transceiver, the Thames & Kosmo Radio Ace.
Where to find cigar boxes
The best place to find cigar boxes is your local cigar shop. Search for them in Google and call around. Better yet, pay your local shop a visit. I have gotten all the boxes I’ve ever needed from the Owl Shop in New Haven (where I’m a regular customer). The Owl Shop puts out dozens of cigar boxes on the curb each week and they are free for the taking. Some shops will charge you for empty boxes and in my experience, you can find great boxes for under $10.
Online sources for cigar boxes include eBay and Etsy as well as craft suppliers such as Michael’s, Hobby Lobby and cigar box guitar kitter CBGitty.
Tools for the job.
In addition to your usual electronic kit tools (solder iron, nippers, pliers, screwdriver) you will need some basic woodworking tools for preparing the cigar box.
A small drill press with a set of hole saw bits will go a long way in terms of being able to drill neat and precise holes for mounting speakers, meters, tube sockets and holes for switches, potentiometers, varicaps and power, antenna and key sockets.
You will also want to have a small hacksaw and coping saw, files and sandpaper. A square with level is essential for precisely locating the places you want to drill.
I also recommend having a good set of drawing tools that include rulers, compasses and protractors. I am a huge proponent of taking the time to sketch out your box layout and design before drilling any holes. I keep a lab notebook in which I document all of my projects. This is taking the adage, measure twice, cut once to the next level. It’s time well spent and in the end you will have a nice record of your projects, not unlike your logbook of on air contacts.
Keys for success
Proper planning is the biggest key to success, but other keys include:
Keep & use a workbench notebook. Document all aspects of your project and sketch the circuit, parts and chassis layout. When laying out placement of parts, measure and remeasure. Then measure again.
Challenge yourself to k three-dimensionally. You have several planes on a cigar box in which to place parts – the top and bottom of the hinged lid, the bottom of the box, and the inside and outsides of the four sides.
Prototype whenever possible!
Keep leads short, but allow enough space for troubleshooting and future mods.
Keep damaged boxes for properly sizing holes for future projects.
Cigar box anatomy and project layout
Start by considering the cigar box from all angles. Turn it over and rotate it and imagine how you want the finished project to look. Consider various placements of parts, controls and circuit boards or terminal strips. Keep the end user in mind and consider ease of use and ergonomics.
You need to pay special attention to the location of the hinge for boxes with hinged lids. The hinged edge is the only place you can route wires from the lid to the bottom or other sides of the box. The back side of the box will logically become the front side of your project where you may want to place switches and controls.
You will also need to be mindful about the depth of parts, measure for adequate room and alignment of all parts when the lid is closed. Consider too that cigar boxes are sometimes made of thin wood and weren’t intended to contain or support heavier components like transformers. Support and balance are both important. You may wish to reinforce the lid or sides by gluing in square dowels. You can also add corner reinforcements found at your local hardware store for additional reinforcement.
Relocating controls off of the PCB
Many modern kits have switches, pots and other controls mounted along the edge of the printed circuit board and are intended to meet the front panel of an enclosure. Sometimes this makes for an easy way to mount a project inside a cigar box. Another option is to move or replace these parts with chassis mounted parts that you can reposition on the front or top of the cigar box. This gives you more flexibility in terms of control placement.
Being non-conductive, your wooden cigar box won’t provide shielding like a metal chassis. This may lead to problems in terms of hand capacitance or interference from other nearby appliances that generate RF. Lining the inside of the cigar box with a layer of heavy duty foil can help. Foil is easily cut & sized and adheres quite well with white glue or a glue stick. Heavy duty aluminum foil is good and cheap, and copper foil is even better but costs more.
I recommend measuring the inside dimensions of your cigar box and then sketching out a pattern on graph paper. Then, using a cutting mat and ruler, transfer the pattern to the foil and carefully cut the foil. Then, starting from the bottom of the box, use glue stick to apply the foil.
Potentiometer and varicap shafts, switches, and other chassis mounted connectors may be too short or shallow for thicker cigar box lids or sides. One solution is to countersink a larger diameter hole on the outside of the box to provide space to flush mount a lock washer and nut. However, many cigar boxes feature soft wood which may easily splinter. When enlarging a drilled hole in soft or thin wood, use a larger drill bit and turn it gently by hand.
“You can’t use up creativity. The more you use, the more you have.” ~Maya Angelou
Some selected AB`1DQ creations
To perhaps help spark your imagination and as a means to illustrate some of the construction points I outlined above, the remainder of this article showcases a few of my cigar box projects.
Basic Code Practice Oscillator
I recently built a basic 2 BPT code practice oscillator using the Boy Scout WN0BSA schematic found all over the internet and sketched out my parts layout using Windows Paint.
This project was a bit of pure nostalgia for me as my first childhood cigar box build was a simple transistor CPO similarly mounted in the same fashion with the key attached to the lid in an old Dexter cigar box.
For a simple old school project, I decided to use a pair of terminal strips mounted on the bottom of my cigar box. My CPO layout pushes the abilities of the cigar box a bit further. Choosing a cigar box with a flat lid that folds out flat to the rest of the box when opened and placed upside down, I mounted a J38 key to the lid and pasted a copy of the International Code next to it. With the speaker also mounted to the bottom of the box, the end result is a nifty flip open all in one CPO.
This project was a bit of pure nostalgia for me as my first childhood cigar box build was a simple transistor CPO similarly mounted in the same fashion with the key attached to the lid in an old Dexter cigar box.
QRP Guys 40 Meter Easy Receiver
I loved the basic kit offerings from the folks at Pacific Antenna. A few years back, along with my fellow advisors to the Amateur Radio Club at Yale, we led a Wednesday Night Workshop at the Yale Center for Engineering Innovation and Design.
The workshop was intended to introduce the uninitiated Yale students, faculty and staff to the basic principles of RF and after a brief presentation, the group paired up and each team built the Easy Receiver Kit. Despite the fact most had never soldered, in the end we had successfully built 10 out of 10 kits. The students in particular were overjoyed when they were able to hear their radios oscillate on an HF rig we brought in.
I decided to give my Easy Receiver the cigar box treatment and mounted it in a small CAO Perfecto cigar box. This is an example of where I measured and drilled out properly spaced holes in the cigar box lid so I could mount the lightweight PCB using just the shafts of the potentiometers.
I added an 8 ohm speaker to the lid, a switchable 3.5mm audio out jack for the use of phones, along with a chassis mounted coaxial barrel power connector, an on-off switch and a power on LED indicator.
Utilitarian LM386 Audio Amplifier
The LM386 audio amp IC makes it simple to add an audio stage to any receiver project. The chip requires no more than a handful of passive components to build a robust amplifier and the internet is flush with schematics and plans. Here is a schematic for the most basic LM386 audio amplifier, taken from the www.circuitbasics.com website.
If you don’t have the necessary components on hand in your parts bin, there are many kits available online with the PCB and all necessary components, aside from the speaker. Prices range from about $10 from US retailers and can be found literally for pennies offered by Chinese retailers like AliExpress.com
While I have incorporated this amplifier into some of my receiver projects, I have also come to appreciate the value of having a standalone amplifier on the operating bench.
Here’s a cigar box build from a kit that also includes a tone control. Again, I mounted the PCB directly to the lid of the cigar box measuring and drilling holes to accommodate the board mounted potentiometers. The SPST toggle power switch is chassis mounted and placed in line with the volume and tone control.
The “transistor tester” kit is fairly ubiquitous online these days and as a frequent kit builder, I have found it to be an indispensable tool when working with small leaded components given their shrinking size and my diminishing vision as I get older. The tester has three terminals to which you can attach resistors, capacitors, inductors, diodes and transistors. The 2 line display returns the type of component and its value and will even indicate the terminals for diodes and transistors.
I built my transistor tester into a cigar box, mounting the display, controls and the terminals to the top of the box. I used three 6-32 screws for the terminals and they are spaced so I can hold most 2 leaded components directly to them for testing. I store three alligator clip jumper cables inside the box when not in use so they are at the ready for short components or when testing three leaded components like BJTs.
I made a couple of mods, replacing the on board trimmer pot that controls display contrast with a same value chassis mounted pot and I moved the power on LED from the PCB to the cigar lid as well.
Ramsey QRP-20 CW Transmitter
Ramsey was a prolific retailer of simple electronic kits and offered a wide variety of ham radio kits as well as other non-radio projects. Their products featured a nifty two piece black plastic project box with pre-drilled end pieces to accommodate the controls for the specific project.
I had built several of their kits over the years, but sadly it’s been a while as the company abandoned the hobby kit business several years ago.
This past winter I spotted an unbuilt Ramsey 20M transmitter kit available online at a not-so-unreasonable price. I purchased it and really enjoyed putting it together. The kit came with the black plastic enclosure, but I realized the dimensions of the PCB were nearly a perfect fit for the inside of the small Oliva Nub cigar box.
I have already blogged about my build, which you can read in detail here.
Since my build, I I made a mod in order to give me not two, but three selectable frequencies. I added an octal tube socket to the left side of the cigar box and installed another DPDT toggle switch. The octal socket will accommodate two FT243 crystals so by wiring per my diagram below, I now have a versatile QRP rig.
The Heil Pine Board Project Reimagined
Many folks reading this may already be aware of the Pine Board Project, an old school DIY AM transmitter project with four distinct sub-projects – field strength meter, power supply, audio pre-amp w/ equalization and the transmitter itself.
About five years ago (my how time flies!) Bob Heil presented the projects with step by step instructions and updates each week on the HamNation podcast. And the project was also featured in QST, and on Heil Sound website.
I initially built the project as originally presented on slabs of pine wood but then converted my build into cigar boxes. As with the Ramsey QRP-20 above, I have already blogged about my transformation of the power supply here.
I plan to revisit my build and expand my blog post on the rest of the project in the future, but in the meantime, here are some photos of my cigar box mods.
Ham radio is unique among all radio-service hobbies as we are not just allowed, but encouraged, to build our own gear and to experiment.
Working with cigar boxes scratches my creative itch as I build gear that is uniquely me.
Where will you find your niche? My charge to you: GO MAKE STUFF!
Thanks for taking the time to read my article. If you enjoyed it or have further questions or want to share ideas or want to leave any other feedback, please leave a comment below or feel free to drop me a line at firstname.lastname@example.org.
I would love to hear what is on your workbench these days!!!
As I venture deeper into scratch building I’ve recently become aware of how useful it would be to have an old school dip meter on the workbench to verify the resonance of LC circuits in the receiver circuits I’ve been experimenting with.
In the back of my mind I’ve always been aware of the existence of the dip meter and the tube era term “Grid Dip Meter” seems to have been rooted in my mind going back to childhood. I’m fairly certain the term appeared on amateur licensing exams I’ve sat for, and I know it was ubiquitous in many of the old 60s era Pop Electronics I used to read in my grandfather’s radio shop.
I started a search online to learn more about the history, design, use and availability of dip meters, sometimes called ‘dippers’ today. In the solid state era, field emission transistors (FETs) and sometimes bipolar junction transistors (BJTs) have largely replaced .
FUN FACT: FET based dippers are sometimes called Gate Dip Oscillators while BJT based dippers are sometimes called Emitter Dip Oscillators.
The dip oscillator isn’t a precision instrument by today’s digital standards and several factors could lead to inaccuracies. Despite that, it has numerous practical uses in the amateur radio station. In addition to being used to measure the properties of resonant circuits, filters, and antennas, a grid dip oscillator can also be used as a signal generator, to measure individual component capacitance or inductance and they may also be used for transmission line testing.
I discovered that back in the day, the amateur radio builder had several options to assemble their own GDO from kits. As expected, Heathkit offered several dippers in kit form throughout their history including the Model GD-1 and later, the HD-1250.
I found several of these old Heathkit GDOs available online and at pretty reasonable asking prices. But as always, when buying used vintage electronic gear, it’s a crap shoot in terms of whether the item bought sight unseen will come complete and be operable. So I decided to explore whether any of the niche kitters offered a modern day equivalent that I could build myself.
This is where I discovered HecKits (www.heckits.com) operated by kit designer and ham radio operator WA7OIB, Darrel Heckendorf. Darrel offers several kits priced under $100 that may be of interest to the QRP builder including an SWR Bridge/Frequency Counter, a Step Attenuator, a CW Keyer, and of interest to me, an FET Dip Meter.
I ordered the FET Dip Meter kit online and quickly received an email from Darrel, thanking me for my purchase, asking me to confirm my shipping address and to inquire whether or not I wanted him to include the optional 6M coil. I had initially missed this email and by the time I replied a day later, I had discovered Darrel had already shipped the kit with the 6M coil at no extra charge and the kit arrived a couple of days later… wow!
I sat down to build the kit this weekend and it was the perfect project for a relaxing Saturday afternoon at the workbench. My initial HecKit experience was everything I look for in kit building.
The kit was well packaged and parts were in clearly labeled zip lock bags. The quality and the fit and finish of the PCB and project case were exceptional. The plastic case fit together precisely and has a nice quality feel about it. The PCB was not thin and flimsy and it featured double sided holes. While it did not have silk screening for parts placement, that was not a problem because the instructions included a large easy to follow diagram of parts placement on the PCB.
Overall, the instructions and documents which Darrel sent by email as a PDF along with my order confirmation was exceptional. Darrel provides a nice introduction to the product and includes several links to learn more about the theory and operation of the dip oscillator and the step by step directions are very easy to follow. Documentation included not only the PCB parts placement diagram, but also full schematics and very clear easy to understand directions for winding the interchangeable coils.
I give Darrel and HecKits high marks for putting together what I would consider a perfect DIY kit. It’s worth mentioning too that the kit came complete with no parts missing.
From start to finish I spent less than 3 hours on the build with the exception of winding the coils, which I still need to do. Generally I don’t mind winding toroids and coils, but the coils for this kit are just a bit small and a tad fiddly for my aging eyes and increasingly shaky hands to easily manipulate, so I thought I’d complete the other coils later on this weekend when I’m feeling fresh. The kit did come with the first coil covering the 1.3 – 2.8 MHz range pre-assembled and it allowed me to verify that my meter worked properly upon completion of the build.
If you’re a QRPer and a builder like me check out Darrel’s offerings at www. heckits.com. As I mentioned, there are several other projects on his site that have caught my eye, particularly the Step Attenuator and the QRP mW meter. I look forward to putting my dipper into use on the workbench as well as my next HecKits build.
Thanks for taking the time to read my blog today. Please leave a comment and let me know if you’ve built this kit or any other of the HecKit lines or share your experience with using a dipper in your station.
One of the most formative experiences that launched me on my radio path occurred when I was about 11 years old and in junior high.
I was already in love with electronics and radio having built several simple Radio Shack kits and having spent countless hours in my grandfather’s radio workshop in our basement, devouring his stash of vintage Pop Electronics and DeVry home radio & TV repair coursebooks.
I recall that at the time, the annual school science fair was coming up and I was preparing to do my project on the world of electronics.
In those days, my dad shared an office at work with a coworker who was a ham radio operator. His name was Frank Pariseau, W1AQO, now a silent key. My dad was into the citizen band scene of the late 70s, and he would often tell me stories of how Frank would constantly try to entice him to getting his ham radio license.
One often repeated story was about the day my dad came into the office one morning to find two pieces of masking tape, a short piece followed by a long piece stuck to the wall.
Frank asked dad what that was, and dad replied, “masking tape.”
“No, no, no, Jim,’ Frank exclaimed, “that’s the letter ‘A’ – di-dah, that’s Morse Code! You now know your first character!”
“No Frank, that’s graffiti, you should take it down.”
Despite Frank’s best efforts (and mine in dad’s years), the old man would never get his ham radio license.
However, while Frank may have failed to convince my dad to get on the ham bands, he would probably have been pleased to know, that although I never had the opportunity to meeting him, I acknowledge and give thanks for Frank’s inspired act of generosity he made to me that fall that planted the seed that firmly set me on the path of a rewarding lifetime hobby in radio.
One night my dad came home from work with a surprise under his arm. He was carrying a vintage Hallicrafters S38 general coverage receiver that Frank sent him home with for me to try out.
The radio was a delight for me to behold. I marveled at the beautiful dual tuning dials – the left with its four nested scales with more numbers than I’ve ever seen on a radio, and the one to the right that in sharp contrast had a single scale simply marked from 00 – 100.
Each dial had its own massive tuning knob next to it and there were other knobs and switches with labels I’ve never seen on any other radio – “AM/CW,” “CW PITCH,” “RECEIVE/STANDBY.” And the brand name, “the Hallicrafters Co.” filled my mind with curiosity.
“THE” Hallicrafters – what was a Hallicrafter? How did one become a Hallicrafter? Who were the men of this marvelous group that produced and proudly put their mark on such a magnificent radio?
To briefly answer that last question for you, dear reader, the Hallicrafters Company manufactured, marketed, and sold radio equipment, and to a lesser extent televisions and phonographs, beginning in 1932. The company was founded by William J. Halligan and based in Chicago, Illinois, United States. From just after World War II until the company’s final days in the mid-60s, the Hallicrafters sold several lines of commercial shortwave receivers for the general public, as well as a series of ham band receivers and transmitters.
The S38 was their ubiquitous entry-level shortwave receiver intended for the general public. It was a simple transformerless All-American Five circuit that would receive the AM broadcast band from 540-1650 kHz and then continue through shortwave bands from 1.65 – 32.00 MHz over four switchable bands. The S38 was designed by French born American industrial designer Frank Loewy whose story is another fascinating rabbit hole I recommend those who are curious and appreciate 20th century design to venture down.
The S38 was surprisingly sensitive, inexpensive, simple to operate and remained in production until 1957 with regular design and minor circuit upgrades along the way. The original S38, produced until 1949, was the only radio in the series to feature a tunable BFO to allow the listener to easily peak CW and SSB signals. All following models lacked this feature and these included the S38A, launched in 1949, the S38B, launched in 1950, the S38C, launched in 1952, the S38D which came out in 1955, and finally the S38E which was introduced in 1957.
The S38, A, B and C all featured the distinctive two semi-circular tuning dials – a main dial on the left with a band spread dial to its right, giving these radios a distinctive trademark appearance. The D & E abandoned the circular dual dials for linear dial scales that occupied the majority of the front of the radio.
Reliving that first magical night
I remember my surprise when dad came home from work that night with the S38. Dad’s nightly return to our apartment each evening just after 5 pm was always a moment of excitement for my sister Kristen and me.
For many of our childhood years we’d listen to hear his car pull up and then rush to greet him as he walked through the gate of our yard. Some nights were made even more wonderful when he’d be carrying a surprise gift for us kids.
Those were the best nights when dad had a fresh roll of Kodak 620 film for my hand-me-down Brownie Hawkeye, and of course the most wonderful night came a couple years prior when he brought home “Shadow” a black Cocker/Brittany spaniel mutt who became our beloved pet for the rest of our childhood. All of dad’s wonderful surprises thrilled us, but the night dad walked in with the S38 trumps all – yes, even the dog!
Dad said we could set the radio up after dinner, which seemed to go on forever that night. Worse, after dinner I had to wait further until the table was cleared and he finished washing and drying the dishes – his evening practice of expressing gratitude for mom’s fine cooking and a means to partner with her in mealtimes.
Finally when his evening chores were done, dad brought the radio to my bedroom with a spool of hookup wire, his wire nippers and a flat blade screwdriver. He set the radio up on my desk, using the tools to cut a 20′ wire antenna that he attached to the A1 terminal on the back of he radio. I crawled under the desk to plug in the power cord and we were ready to go.
Dad pointed out the on/off/volume control and invited me to turn the radio on. I did and watched eagerly as the dial lamps came on brightly and then dimmed as the tubes began warming up. A few moments later and for the first time in my life, I heard was the beautiful strange syncopated sounds of Morse code coming from the built in speaker.
I of course had no ability to understand what I was hearing, but I was mesmerized by the sound of the rapidly sent dits and dahs. I pondered what urgent messages were being sent and I envisioned radio operators in their darkened shacks hunched over their Morse code keys before stacks of glowing radio equipment. A child’s imagination is a wonderful thing!
After listening for a while, I tried turning the right hand bandspread dial slowly up and down, and continued picking up many other stations sending Morse Code. I was struck how these signals varied in terms of tone, strength and speed. I discovered that by turning the CW PITCH knob I could change the tone of the dits and dahs and peak their strength. Most of the code I was hearing was being sent rapidly, probably 20-25 words per minute or faster, but then there would be other stations sending slower code at 12 words per minute or less. It was all music to my ears.
Next I tried turned the main tuning dial up and down across the bands, without knowing the band plans or where I might find specific types of stations. Still by using my crude hunt and seek tuning method, the sounds of Morse Code were soon replaced by the distinctive distorted Donald Duck sound of hams operating phone on sideband.
I was captivated listening to the back and forth conversation between a pair of hams, exchanging a series of numbers (signal reports, power output, antenna specs), and some then ‘chewing the rag,’ \shooting the breeze and talking about whatever was on their mind – simple friendly conversation. I would marvel hearing the ham operators state where they were operating from – distant cities and towns across the US, being heard so clearly, and I was further thrilled hearing each operator routinely conclude his turn by giving his callsign. Wow – simply – wow!
Over the next few nights I continued to explore the shortwave bands and discovered more of what they had to offer. Hearing Morse code was magical, even though I couldn’t comprehend what was being communicated, and as wonderful as the hams on sideband were, most of their conversations began to sound the same.
This is when I first heard international shortwave broadcast stations such as the BBC, the Voice of America, Radio Moscow, and dozens and dozens of others from all over the world. Of course growing up in the 70s, I was coming of age in the height of the Cold War and all nations, whether from the East or the West, would have state sponsored shortwave station that broadcast the daily news and their editorial views nightly. It was a real education to hear how the same global news story could be reported so differently when presented by a Western station such as VOA, BBC or Deutsche Welle, or by an Eastern bloc station like Radio Havana, Radio Tirana or Radio Kiev.
The international shortwave bands were chock full of Cold War propaganda!
After the news & views content that started every broadcast, the majority of these international broadcast stations would then move onto cultural and entertainment programming. Several had ‘mailbag’ programs where listener letters were read on the air and responded to. Some stations had language lesson programs, some reported on local cultural customs and seasonal events such as festivals, and most had ethnic music programs.
What a world that Frank’s simple gift of the S38 opened me up to. Recall that these were the days long before the internet, streaming video, and even basic cable. Up to then I was living in a world of three network TV stations plus the PBS station, and all that AM and FM radio had to offer.
More about the S38
As I mentioned, the S38 was ubiquitous in its day, and despite having concluted production 60 years ago, these radios remain ubiquitous in the radio hobbyist community today. It’s almost impossible to attend a ham radio flea market without seeing several, and there are dozens continually up for bids on eBay.
Similarly, there are many excellent web resources where S38 enthusiasts have published the receiver’s history, technical data such as schematics and servicing instructions covering essentials such as recapping and realignment, as well as performance and safety mods. I will conclude this blog entry below with a few links to some of my personal favorite S38 websites. But, while web certainly didn’t need another S38 fan page, given the radio’s foundational role in my radio story, I would be lacking had I never included a post such as this in my radio blog.
The S38 is a superheterodyne receiver using frequency mixing to convert a received signal to a fixed intermediate frequency (IF) which can be more conveniently processed than the original carrier frequency. Quoting the S38 1949 user manual…
Radio signals are picked up at the antenna and fed to the antenna coil of the mixer stage where the desired station signal is selected by a resonant circuit and fed to the mixer tube. At the same time, the oscillator section of the tube generates a local r-f signal which is mixed with the incoming station signal. An intermediate frequency of 455 kc is selected by the first i-f transformer and fed to the i-f amplifier tube where it is fed throught the second i-f transformer to the dectector-first audio amplifier where it is demodulated. The audio component of the signal is then amplified by the triode section of the tube and capacity coupled to the audio output tube where it is further amplified and fed to the speaker.
The Hallicrafters Co., Installation and operating instructions for the model S-38 radio receiver, August, 1946, 94-162-A
The S38 circuit was the popular “All American Five” design, which was used in hundreds of radio sets by practically every radio manufacturer of the era. The AA5 was a sensitive superheterodyne circuit that lacked a power transformer and could be operated using either an AC or a DC power supply of 115-125 volts. By not including a power transformer, AA5 radios provided an inexpensive radio choice for the consumer of the day.
However this cost saving feature also contributed to making these radios a bit more dangerous for the user. Typical of radios and electric appliances of the 1940s, the S38 did not have a polarized plug on its line cord which means you have a 50% chance of connecting the chassis ground side of the radio to the household ‘hot’ connection rather than the safer neutral connection. This had the potential of resulting in a dangerous electric shock for the user if the rubber washers that insulate the chassis from the cabinet deteriorated and failed. Because of how the on-off switch was wired in this ‘hot chassis’ design, the risk existed even if the radio was switched off.
An essential practice for anyone servicing or restoring an S38 today is to install a polarized plug and wire it so the neutral wire goes to ground and the hot lead is connected to the power switch which is relocated to pin 2 of the 35Z5 tube on the opposite end of the filament chain. Adding a fuse to both power leads is also a good idea. Whenever I restore an S38, in addition to replacing the leaky wax and electrolytic capacitors, I make the following modification.
Phil Nelson has maintained his excellent website dedicated to restoring the Halicrafters S38 since 1995 and its an excellent starting place if you want to learn more about the S38. He also has instructions on how to add an S-meter to your radio.
WD4EUI, Allen Wooten of Huntsville, Alabama has an excellent page on his restoration of an S38C complete with excellent detailed photos including several on repairing damaged IF transformers.
The Sam’s Photofact for the original S38 model, including schematics, parts list and alignment instructions can be obtained as a PDF here.
John Fuhring describes his restoration of his S38B complete with detailed photos and a schematic for a mod to add an FET based BFO here.
Read reviews of the S38 from ham radio operators on the eHam product review site here.
AI4FR, John Whitt of Dade City, Florida has a detailed page dedicated to his resto-mod of an S38 including his safety modification to prevent shocks.
VE7SL, Steve McDonald of British Columbia describes his S38 restoration here.
As I said, there are no shortages of websites dedicated to S38 restoration and use. Thanks for visiting mine and reading my personal story.
Do you or did you own an S38? Which model was it? Did you restore it or modify the radio? Do you still use it today? What are your thoughts or impressions? Drop me a line a email@example.com and share your story!
Every Spring Yale University organizes a fitness program for the community called The Yale Trail in which staff are encouraged to start a daily walking program. Last Spring, I posted a single photo taken during each of my morning walks to my Instagram account under the title “Good Morning New Haven.”’
Here is a gallery of my favorite photos taken during those walks in the Spring of 2021. All were taken with my iPhone using the Hipstamatic app which emulates the fantastic plastic toy cameras I used to favor.
Comments and feedback are always welcome and as always, thanks for looking!
Every Spring Yale University organizes a fitness program for the community called The Yale Trail in which staff are encouraged to start a daily walking program. Last Spring, I posted a single photo taken during each of my morning walks to my Instagram account under the title “Good Morning New Haven.“’
The 2022 program is now underway and runs through May 10, 2022. This year I intend to post a photo a day taken while walking along Dixwell Avenue.
Besides being perhaps the best named road in all of New Haven County, Dixwell Ave. is a commercial and residential wonderland that stretches for several miles through New Haven, Hamden, and North Haven and is positively stupid with urban delights such as hand painted murals, colorful signage, fascinating architecture, and intriguing statements of ethnicity and individuality. See below for a description of my photographs above and links to learn more about my subjects.
WHAT’S A HIPSTAMATIC?
Hipstamatic is an iPhone camera app that allows the photographer to emulate a variety of toy and lo-fi film cameras.
Toy camera photography became a cult thing in the photography community in the 90s and into the 21st century. Using cheap plastic medium format cameras such as the Diana and the Holga, renowned for aberrations such as light leaks and ill-formed plastic lenses, photographers are able to produce very distinctive ‘sloppy’ and artsy photos.
The Hipstamatic app allows the user to change virtual lenses, films, flashes to produce digital images that have the qualities of toy camera photographs. For this years gallery I have chosen a combination of settings that produces over-saturated high contrast images with a distinctive black rounded border that emulates the Through-The Viewfinder style of photography.
Please consider bookmarking this page and coming back each day to see what has caught my eye. This year I am challenging myself to take all photographs with the Hipstamatic toy camera app on my iPhone SE using the same settings for a cohesive gallery. I hope you enjoy my efforts.
TWENTY YEARS AGO, TODAY the FCC sent greetings and I was issued my first amateur radio license, Technician Class ticket, call sign KB1IAR.
Two weeks prior on a chilly Thursday evening, I had nervously sat for, and passed, the Element 2 license exam held at the Red Cross on Gano Street in Providence, RI.
A lifelong ambition, and something I rightfully should have done during my teen years as all the seeds and passion for all things radio were already planted and had taken root, was finally achieved at the age of 35.
Sometime that January I was in my local Radio Shack purchasing materials to erect a long wire antenna for my shortwave radios at the new house I had purchased in Manville, RI when I spotted the Now You’re Talking! Technician Class amateur license guide on the shelf.
I flipped through the pages and thought to myself, why not? The material looked straightforward, most of the technical electronic material was already familiar and I thought that if nothing else it would kind of neat to hold an amateur radio call sign, even if I never actually purchased a radio and got on the air.
This was also in the months immediately following the 9/11 attacks and it seemed like being able to communicate with others should more horrific acts occur, might be a good idea. So, I made an impulse purchase of the study guide and after two or three weeks I felt I was ready to take the test.
I of course DID get on the air pretty quickly. The first radios I purchased was a pair of Icom IC-1000H FM 2-meter transceivers, one I installed in my Ford Focus, and the second went into my first ‘radio shack’ an unused bedroom that served as my ‘man cave’ in our new home. This bedroom conveniently had the access door to the attic which allowed me to easily snake coax from the radio into the attic where I had installed a Ringo Ranger vertical antenna.
I also purchased my first hand-held radio, an Icon IC-V8 which was an entry level bare bones 5-watt transceiver for the 2-meter band. The IC-V8 was a distinctive looking radio with it’s green plastic casing and non-rectangular body. I still have the IC-V8 and use it on Tuesday evenings in the warmer weather months to check into the Meriden Amateur Radio Club Tuesday night 2-meter net from the front porch here in Cheshire.
It wouldn’t be long before I upgraded to my General Class license a few months later earning me HF privileges that would allow me to work other hams around the world on the shortwave bands, but today I fondly recall and feel nostalgia for my initial experiences as a Tech.
The past two decades have been nothing short of TOTALLY AWESOME and I expect the next twenty to be just as good! If you are considering getting your ham radio license, I wholeheartedly encourage you to go for it. It’s never been easier to earn that first license and there are many resources out there to help you prepare for your exam. I’d be happy to help point you in the right direction if you’d like – drop me an email at firstname.lastname@example.org.
This morning I completed the Front Panel Board, the second board of the Elecraft K2 HF Transceiver Kit build that I began at the start of the year. After completing the Control Board on January 17, I took a complete month off working on other weekend projects before starting the Front Panel on February 21. I did state from the get go that I was going to take my time with this, my most ambitious kit build, and I’m staying true to my word.
The Front Panel Board is where all of the user controls are mounted. These include the large rotary encoder/tuning knob, the numeric keypad and pushbuttons, and five variable resistors. This section also includes the graphical LED status bar display and the LCD main display.
Assembly of the front panel starts by soldering the sixteen tactile push button switches to the printed circuit board. For a proper and neat professional appearance, it’s essential that all of the switches be mounted at a precise uniform distance from the surface of the board.
Elecraft provides a nifty switch spacing tool in the kit which is essentially a thin narrow bit of PCB material that is placed under each switch which is then pushed flush to the spacing tool. This clever method worked exceptionally well for me.
After the switches are mounted, the board is populated with the usual components – resistors, capacitors, diodes and transistors. The front panel board has four ICs including the large 40 pin U1 which is mounted on the bottom side of the board and behind the display.
The front panel board also has a good bit of hardware to be attached including the eight-pin microphone jack and several spacers. Up to this point the instruction manual has been absolutely excellent in providing detailed easy to follow accurate directions.
However, I did encounter some difficulty when it came to mounting the main display components which consists of two backlight LEDs, their spacers, a white cardboard reflector, a frosted plastic diffuser, and the 40 pin LCD.
As I discussed in my previous post, the Elecraft K2 is a fabulous kit, but it’s a rather old kit, first prototyped a quarter century ago – in 1997! Understandably in the time since its introduction, some components become ‘unobtainium’ as the years go by. Vendors come and go and with advancing technology, manufacturers discontinue production of now archaic through-hole components with today’s increasing popularity of SMD architecture.
Thus, when one buys a K2 kit today, it will come with several pages of errata that must be carefully consulted and reviewed. Builders in 2022 will find themselves crossing out sections, sometimes whole pages, of the original manual, and adding notes about the replacement modern components packaged with their kit.
This was the case with the display assembly. I was instructed to cross out most of the directions pertaining to the installation of the display on pages 27 and 28 of the manual and to follow the alternative directions provided as errata.
The revised directions call for the builder to first insert the leads of a pair of rectangular LEDs through plastic spacers and solder the LEDs flush to the board to the left and the right side of where the LCD will be mounted.
Between the two LEDs, the builder places a white cardboard backlight reflector and then mounts a frosted plastic diffuser by placing it over the the two LEDs on the left and the right side. The diffuser has an indent on each side to accomondate the LEDs.
I found this all went precisely as described until I came to the step that instructed me to place the LCD flush on top of the diffuser and then solder the 20 pins of the LCD to the associated pads on the PCB.
None of the LCD pins were long enough to go through the holes in the pads on the board. If pressed flush to the diffuser the LCD pins just barely touched the pads.
I carefully checked the instructions and my work. I was certain I mounted the LEDs correctly and flush to the board with their spacers, and the cut outs on the bottom side of the plastic diffuser neatly accommodated the LEDs perfectly.
Realizing that proper positioning of the LCD would be critical for the PCB to properly fit in the front panel and knowing that not getting the spacing correct would also give the finished radio a sloppy appearance, I reached out to Elecraft for help via their website.
I dreaded the prospect of having to de-solder 20 pins and run the risk of damaging the LCD if I needed to remove it after it was soldered in place. I wanted to get as much information as I could before proceeding.
I received an email reply from Dave at Elecraft who is their K2 support guy within a couple of days. Dave stated that it was ‘perfectly normal’ for the LCD pins to just touch the top pads on the PCB and that they do not need to protrude through the holes. He said that his last K2 build was like this and suggested that I carefully solder the 20 pins from the topside, but to make sure the LCD is level and parallel to the board.
I did as Dave recommended, carefully aligning the LCD so it was level and evenly spaced above the board. I started by soldering each of the corner pins and confirming the LCDs position after each solder joint. Once done, I applied solder to the pads on the bottom of the board to let it flow through the hole to help ensure solid contact.
However, after I soldered just under half of the LCD pins, I realized I had left out the cardboard reflector. D’oh! There was no way I could slide the stiff cardboard under the pins at this point and I didn’t want to have to de-solder so many pins, so I came up with a workaround.
I took a piece of white copier paper and cut a rectangle to the same size as the cardboard reflector. Cutting the paper in half, I was able to slip both halves between the gap in the pins on the bottom of the LCD and position them in proper place. I held them in place with a bit of cellophane tape.
From here on out the rest of the front panel assembly went smoothly. Again I encountered the need to reference the errata for the main encoder knob as Elecraft includes a different unit than the one referenced in the original instruction manual. The encoder in my kit required me to solder a few parts into an auxiliary board to which the encoder was attached. The auxiliary board is then attached to the back of the front panel board.
The last step was to mount the completed front panel board inside of the front panel. Before doing so, the manual lists about 30 resistance checks for the board. Each test point checked out as specified to ground – excellent!
I was very pleased that after I carefully mounted the board the front panel looked perfect. All of the push buttons were a proper and uniform height through the holes on the panel. All knobs, including the main encoder dial, were also correctly mounted and turned with ease. Best of all the main display LCD that caused me so much grief, looked perfect under the front bezel.