Elecraft K2 Build – Part 2

Front Panel Assembly

March 20, 2022

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.

With the LCD flush against the frosted crystal diffuser, the pins are too short to penetrate the holes in the pads.
A view of the bottom side of the board showing the inadequate length of the LCD pins.

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 rotary encoder auxiliary 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.

Completed Front Panel PCB, front.
Completed Front Panel PCB, back.
The completed front panel…. it ‘looks’ like a radio anyway.

Next up – the RF Board. Stay tuned….

QRPGuys End-Fed Multiband Antenna

“Unique ham radio kits for the budget minded.” That’s what the masthead proclaims on the QRPGuys website and that is exactly what you’ll find there – a collection of project kits for the builder/QRPer that aren’t found on other kit sites and all offered at a more than fair price.

Current transceiver kits include their AFP-FSK Digital Transceiver, now in its third edition and they also offer a wide variety of other QRP essentials including several antennas and tuners, test gear including power meters, attenuators and filters and other accessories,

The QRP Guys are an affiliation of a “who’s who” of QRP building and will give you an idea of the innovative and high-quality products they develop. Ken LoCasale (WA4MNT) provides kit mechanical design, board layout and documentation, and NorCal cofounder Doug Hendricks (KI6DS) is credited with logistic support and beta testing.

Circuit design is by Steve Weber (KD1JV) of Pacific Antenna, Dan Tayloe, creator of the N7VE SWR Bridge, and Cliff Donley (K8TND). Both Steve and “Kazu” Terasaki (AG5NS) author firmware, technical assistance is given by beta builder Yin Shih (N9YS) and John Stevens (K5JS) is credited with assisting Ken with website maintenance.

Building the QRPGuys 40-30-20 M End Fed Antenna

The QRPGuys multiband end fed antenna meets my definition of an easy build with only 16 solder-in components on the main tuner circuit board and the two traps. I started as I do with all of my kit builds by inventorying and arranging all of the parts. I have been using cigar boxes with clasps on their lids to prevent me from losing small parts before they are needed. Cigar boxes are also ideal for storing works in progress kits when a project will extend beyond a single building session.

This easy to build kit has a minimal number of parts.

The prospective builder should be forewarned that of those sixteen components, four of them are inductors that must be hand-wound on toroid coil forms. Many builders seem to abhor the winding of coils, and while I find it sometimes fiddly work, I’ve come to not mid the process.

I give props to the writers of the QRPGuys manual, as they provided some of the clearest instruction on how to wind the inductors, including the number of loops and where to place the taps. The manual also includes a nicely done illustration of each inductor and hints on how to assure the builder wound them correctly.

The diagram from the instruction manual clearly depicts how to wind the four inductors.

The inclusion of Thermaleze® brand magnet wire for the inductors was also a nice feature – the enamel coating was quickly dispatched after a few seconds of exposure to my Zippo cigar torch.

The entire build, including the winding of the four toroids, building the traps and measuring the three driven element lengths of wire took me less than 2 hours working at a leisurely pace on a winter’s Sunday morning.

About the Antenna

Field testing this antenna will have to wait a few more weeks for more reasonable weather here in Connecticut, but my plan is to use this antenna for QRP POTA activations this year with various homebuilt radios such as the Ramsey QRP20 transmitter I assembled last week. The end-fed design should make for easy deployment as a sloper while operating from the field with easy access to the tuning controls from my operating position.

The tuner circuit design is as straightforward as it gets – your basic tunable L-C circuit with a varicon capacitor. But the kit also employs the N7VE LED absorption bridge that keeps SWR to a minimum of 2:1 when set to the tune position. According to the kit documentation, the LED indicates only reflected power. Full LED brilliance will indicate an SWR at 4:1 or greater. At half brilliance SWR is approximately 2:1, and the LED will completely extinguish at 1:1.

I was impressed with the apparent high quality of the PCBs and components, and I found the instructions and supporting documentation to be exceptionally well written – easy to follow and understand.

If you would like to build the QRPGuys Multi-band End Fed Antenna, you can purchase the kit on their website here. The current price of the kit is $40 USD.

If you have built this kit, or have any questions or comments, please feel free to leave a comment or drop me a line at james@ab1dq.com.

72 de AB1DQ/James

The Heil “Cigar Box” Project?

Legendary sound engineer Bob Heil, architect behind many signature rock artist signature sounds (The Who, The Grateful Dead, Peter Frampton, Joe Walsh to name a few), is also renowned in the amateur radio community.

Bob has engineered and his firm Heil Sound retails high performance microphones and other premium gear for the ham community, he has authored books and numerous articles for the ham community and is one of the most sought-after speakers for amateur radio conferences. Bob hosted the popular TWiT video podcast HamNation from 2011 through 2020; archived copies of the podcast remain a valuable resource to hams today.

In the Spring of 2017, Bob Heil introduced to the amateur radio community, The Pine Board Project, a four-part do-it-yourself AM transmitter project. In earlier times, building your own gear was a larger part of the ham radio experience. RF theory and design made up a larger portion the exam material and while studying, many prospective Novices would construct their own basic receivers and transmitters while studying for their licenses.

Plans for these projects were widely published – from the American Radio Relay League’s handbook and monthly magazine, QST, to other popular radio and electronics magazines such as CQ, 73, Popular Electronics, Radio TV Experimenter, and Elementary Electronics.

The Heil Pine Board project was a throw-back to these times. Bob broke the project into four separate sub-projects for the builder to construct: an RF field strength meter, a high voltage power supply, an audio pre-amplifier and equalizer, and a 40/80-meter transmitter capable of approximately 5 watts AM output.

Several episodes of HamNation included featured segments in which Bob would take the prospective builder through circuit design, parts layout, and circuit theory. Bob published the schematics and board layout diagrams on the Heil website and even provided parts lists with sourcing information, giving the names of firms that carried some of the obscure parts from an earlier era, along with stock numbers and prices.

Bob’s enthusiasm for the projects as expressed in the videos was infectious. His presentation style was straight forward, detailed and inviting for the new builder. Along the way he featured photos and reports of viewers’ work.

I was hooked from the get-go. I grew up spending hours on ends in my grandfather’s TV/radio workshop in our basement and had read dozens and dozens of articles for building projects that appeared in the yellowing pages of his electronics magazines from the 60s. I had built many an electronic kit in my time, but beyond the occasional simple crystal radios or basic transistor circuits, I never did much scratch building.

I started building the projects a couple of years ago, closely following the directions and completed the field strength meter, the power supply and the pre-amplifier. Then, true to form, I either got distracted by other things (other projects, family, work, life itself).

Last summer (2021) I made a resolution to focus and complete the unfinished projects on the shelves of my workshop and decided it was time to complete the Heil project.

Friends who know me well, know that in recent years I had enjoyed the occasional cigar. Many a workweek transitioned into the weekend by enjoying a fine Leaf by Oscar and an Old-Fashioned with my dear friends Carl & Steve at the Owl. Every week or so, the Owl staff would leave empty wooden cigar boxes out at the curb for folks to take and I started nabbing a few thinking they might make good chassis for ham radio projects.

Since then I had built a few recent projects into my cigar boxes and thought that it might be fun to put my cigar box spin on Bob Heil’s transmitter project and built the transmitter into a cigar box and then rebuilt the other projects into their own cigar boxes.

At this point I’m going to blog on my Heil Pine Box/Cigar Box Project experience in a series of articles, starting with the power supply. As I mentioned I initially built this on a pine board and my initial build used the 5XT rectifier tube using Bob’s original design. I have replaced the 5XT with the solid-state rectifier, building the modified power supply as designed by and published by Bob.

Thanks again to Bob Heil for designing and sharing and promoting the Pine Board Project – it has provided me with hours and hours of enjoyment so far, and there’s much more fun ahead.

Have you built the Pine Board Project? Leave me a comment or drop me a line at james@ab1dq.com. Jump to my post about my power supply build here.

Elecraft K2 Build – Part 1

Control Board Assembly

As the proverb goes, a journey of a thousand miles begins with a single step. So, after procrastinating for two plus years after my XYL and soulmate Ellen gifted me the Elecraft K2 HF Transceiver Kit for our tenth anniversary, I finally got my nerve up to start what will easily be my most ambitious kit build ever.

It is my intent to blog about my experience as I proceed, circuit board by circuit board, sharing my experience and inviting others who have built the K2 to share as well.

The Control Board

Having set up and outfitted a new protected work bench using a folding banquet table in the shack where I will work only on the K2, I started work on the first circuit board, the Control Board on January 9, 2022.

As with many kits I’ve built, the Elecraft instructions call for the builder to start by inserting and soldering all of the fixed resistors first. As others have reported, I found the instructions to be, for the most part, very well written. The instructions for the fixed resistors provided each resistor’s value in ohms as well as the color code and the builder is encouraged to install the resistors with the first color band towards the top or the right of the circuit board to facilitate verifying the correct resistor is in the correct space when reviewing or troubleshooting your work.

As electronic components have gotten increasingly smaller, my vision has gotten progressively worse as I’ve gotten older. Whenever kit building, I always verify values with my VOM before inserting any resistors into a circuit board. After installing the 13 resistors, the instructions called for the installation of seven resistor arrays and one trimmer pot, all easily identified.

The Control Board after installing all resistors.

Next the builder needs to install an 82 mH inductor, which I confirmed I had the correct part with my L/C meter, followed by a pair of silicon diodes. I then encountered the first variation in my kit. Where the original PCB had a screened space for D3, the instructions called for an 82K ohm resistor to be installed here.

The instructions next call for the builder to install and solder in place 36 fixed capacitors. Identifying and verifying the value of each capacitor was a notable challenge. Not only were the stamped or printed values on the caps miniscule, the capacitors also varied in type, shape, and manufacturer and it was clear that some of Elecraft’s suppliers changed over the twenty-five years they have been offering the K2 kit, as some of the caps did not match in appearance to the identifier pictures in the otherwise excellent parts list in the appendix.

To guarantee I placed the correct capacitor in the correct space, I took the time to identify every capacitor and laid them out neatly on my workbench in the same order the instructions called for their installation.

To identify the values, I used the camera on my iPhone and zoom in on the part. Sometimes when the value is etched on the capacitor, I needed to shift it so my bench light catches the labeling just right to read. I took the time and used my L/C meter to verify the value of every capacitor.

Once all of the capacitors were laid out in the order of installation, I carefully installed each capacitor into its space, having taken the time again to double-check values with the L/C meter. It was a slow process, but in the end, I felt very confident all of the capacitors were soldered in the correct space giving me peace of mind. Trouble shooting for mis-placed capacitors would be a very tedious process if necessary.

The next several steps went along easily as I installed the electrolytic capacitors, a trimmer cap, a dozen bipolar junction transistors, a pair of crystals, two voltage regulators, one IC socket and various connectors. All of these parts were easily identified, and when working with the transistors, I proceeded in the same manner as I did with the fixed caps, identifying and verifying value, arranging them in the order of installation and double-checking values as I installed each.

The bipolar transistors, values checked and laid out in order of installation.

Now it was time to install the ICs on the control board, and this is where I first ran into trouble.

The very first chip was an NE602, the AGC mixer. I mentioned that the K2 has been on the market for twenty-four years and over the course of a quarter century, technology moves on and the availability of parts change. By the time Elecraft had kitted my specific K2, the NE602 was no longer widely available in through-the-hole DIP casing. The industry had since begun moving on away from through-the-hole components in favor of tiny, less expensive surface-mount versions.

Instead of the DIP version of the NE602, my kit came with an equivalent SMD NE612 which was pre-soldered to a small square ‘carrier board.’ The carrier board is a PC board cut to the same footprint of an 8 pin DIP case and the builder is instructed to cut eight 1-inch pieces of wire, insert them into the eight holes on the carrier board, solder them in place, then insert the bottom ends of these wires through the DIP-spaced holes and solder to the control board.

I damaged the carrier board while attaching the wires by working sloppily with a too-hot iron. The carrier board was not of the same high quality as the control board which featured double plated holes. The carrier board had plating only on the top of the holes, and I managed to lift the plating off of the number 2 and number 3 hole, breaking connectivity. I tried to bridge the contacts to the chip contacts with a solder blob, but that only made a bigger mess of things.

Elecraft has a form on their website to order replacement parts and I reached out on January 1qth to inquire about purchasing a replacement NE612 and carrier board. I did receive an acknowledgement that they received my inquiry from a mail bot, but as of this writing, four days later I have not received an actual reply.

In the meantime, I began wondering whether I could still find DIP cased versions of the NE602 elsewhere online. I searched Mouser, Digi-key, eBay and Amazon and found that an Amazon vendor had some available, which I ordered. The vendor did not disclose the name of the manufacturer nor the source country, but I’m assuming the chips were manufactured in China. I did order five (there are three others elsewhere in the K2) and they arrived within a day or two.

I discussed my dilemma with one of my Elmers, Steve, KZ1S, who has built many a kit in his day and is a physics professor who works with electronic circuits and RF in his work.

Steve offered a couple of suggestions. The first was to use a proper SMD to DIP converter board with proper pins spaced correctly. I liked this idea very much, but the drawback is that it would require me soldering the SMD chip to the converter board and again, with my failing vision and dexterity, this would be a bit of an unpleasant challenge.

A proper SMD – DIP converter

Steve also suggested looking for genuine NOS chips online, either on eBay, or from Radwell International. Steve mentioned you can source just about any obsolete part with Radwell, but they can be expensive. I did locate the NE602s on there with a retail price of about $5 – not a deal-breaker, but given I need four for the K2, that’s an additional $20 + shipping.

For the time being, I decided to place a DIP socket on the control board and once in place, I inserted the NE602 of dubious origin I purchased from Amazon in the socket. For the time being this would let me continue with the build and be able to test resistances. I could then swap out the AGC chip for a genuine NOS or SMD + converter at a later date.

I finished the build of the control board this morning, directly soldering in the remaining ICs and adding the two CW key-shaping capacitors on the solder side of the board.

After carefully double-checking all of my work, I used my VOM to perform the resistance checks. All of my test resistances were within range, excepting U6 pin 29 (DASH) and U6 pin 30 (DOT/PTT) which were marginally over spec. The acceptable range for both is 70K – 90K ohms and I measured 96.6K on pin 29 and 96.8K on pin 30. I will revisit these values later.

So that concludes the build of the first circuit board, the Control Board. I counted a total of 110 components soldered to the board and I completed the work in eight days working at my deliberately leisurely pace.

I welcome comments and suggestions from any and all, particularly from anyone who has built the K2 and had to deal with the SMD carrier board themselves. Drop me a line at james@ab1dq.com to share your thoughts and opinions.

Next up – the Front Panel Board – stay tuned!

AB1DQ’s MINI Mobile Ham Shack, or, How I spent my Summer of Covid

It had become a long running joke with my wife Ellen, and her best friend Naomi, who has been coming over for socially distant weekend visits ever since lockdown began in March.  When Nay would arrive most Saturdays around noontime, she’d find me outside with my head stuck under the dashboard of my 2012 R56 MINI Cooper and she’d ask Ellen if I was ever going to finish my car project. Truth be told, it really wasn’t ‘one’ car project that I undertook during my summer of Covid, but several automotive upgrades. The focus of this post however, is the installation of two transceivers to create my new mobile “ham shack.”

A SIMPLE PROJECT EVOLVES

It all started when I decided to replace a blown factory speaker.  Well, speakers are sold in pairs and why upgrade the front speakers only?  Soon a package arrived from Crutchfield with a complete set of premium aftermarket speakers.

Replacing the speakers took me back to my teen years when I installed that Kraco Dashmsater AM/FM/MPX stereo that I bought at K-Mart for $30 in my Ford Pinto along with matching 5″ Kraco slimline speakers mounted in the cardboard rear deck.  That Christmas mom & dad made my holiday by getting me the Realistic 40-watt amplifier and graphic equalizer complete with 7 sliders and flashing LEDs that I ‘needed’ to complete my ride! (You can bet your figgy pudding that I was outside right after Christmas  dinner in the subfreezing weather with my wire cutters and electrical tape racing to complete my hi-fi upgrade before sundown!)

The heart of my first car stereo install, circa 1982

So feeling nostalgic, I didn’t stop at the speakers and soon a reasonably priced Kenwood eXcelon DPX594BT double-DIN stereo had also arrived from Crutchfield with bells & whistles that I couldn’t have imagined in my Kraco Krankin’ days  – SiriusXM, Pandora, Spotify, Alexa, Bluetooth, USB, a CD player and of course good ole AM/FM.

The second-generation MINI Cooper features a big ole Speedometer in the middle of the dashboard and the bottom half of that speedometer is where MINI incorporated the factory radio display and memory buttons.  The aftermarket stereo dash kit came with a blank out panel for the factory display and buttons, but this left sort of an unfinished empty look right in the middle of the dash.

MINI R56 Speedometer blanked out for after market stereo installation…. A lot of prime empty space!

And this my friends, is where the inspiration came in.  That big empty space looked like prime territory for a transceiver faceplate. A couple of years ago I purchased a Yaesu FT-891 with the intention of building a Go-Box that I hadn’t done anything with.   I saw that the Yaesu remote head and mounting bracket could neatly be attached to the speedometer blank out plate and this would be an excellent use for the space.  The ‘bug’ bit hard and before you knew it, I was all in on making this happen.

HOW IT ALL CAME TOGETHER

I decided to install not only the HF rig, but also my Alinco dual band UHF/VHF DR735 and I began the project by bolting both radios to the back of the rear passenger seat, with plenty of slack cable so the rear seat could be folded down. I routed the control head cables under the door sills under the edge of the carpeting and on up to the dashboard.  So far, so good.

The two transceiver bodies bolted to the back of the rear right passenger seat. The HF Yaesu FT891 is above the 2M/440 Alinco DR735. Cables are held in place, stabled to the seat back, with plenty of slack to allow the seat to be easily folded up and down as needed.

To power the radios, I ran a 10 AWGdirect line from the battery, through the firewall and under the center console back to the trunk area.  The MINI has a nifty little carpeted access panel for access to the taillights so I used that space to mount a PowerPole distribution block at the back of the car to not only power the two rigs, but to provide a convenient place to plug in any other 12VDC gear I might want for a future outdoor radio event, say Field Day.

One concern that arose was that both radios had speakers built into the radio bodies, which were now in the trunk.  Not so good for this old fart with failing hearing.  I thought about adding an accessory speaker on the dashboard, but in such a small car, space comes at a premium and I’ve already cluttered things up with two new remote heads and microphones.

I decided to try a creative solution and bought one of those cheap-O FM modulators that let you transmit audio from your MP3 or CD player to your car stereo.  I mounted the tiny modulator above the PowerPole block, connected it to the radio audio output jacks, and tuned it to 89.3 MHz, an unused frequency in my area.  I programmed one of the FM memory buttons on the new Kenwood stereo to that same frequency, and now I get my ham radio audio through the stereo speakers.

Here you see the power distribution block and the FM modulator above it, bolted to the inner rear fender and neatly concealed under the removable access door in the trunk area.

For antennas, I went with the Yaesu ATAS-120 screwdriver antenna for HF and installed a lip mount on the rear tailgate.  I was fully prepared to drill through the roof for a better mounting position with a much better ground plane, but my car has dual sunroofs – so that wasn’t a very viable option.  On the other side of the tailgate you will find the 2M/70cm dual band antenna attached by another lip mount.

A MINI Antenna farm… two lip mounts, with an ATAS-120 screwdriver antenna on the driver side and a dual band 2M/70cm antenna for local FM on the passenger side. The MINI’s dual sunroof precluded the option of drilling a better situation HF antenna mount into the roof. The HF antenna placement may need to be revisited…

The last time I had a mobile installation was about a dozen plus years ago when I installed a Yaesu FT-857D in my 2002 Ford Focus sedan and used a four-magnet trunk lid mount with interchangeable mono band ham-sticks.  I did have a lot of fun in those days working into Europe on 20 and 40 M after work while stuck in the parking lot that is rush hour on Route 128 outside of Boston.

When I did the Focus install, I took the matter of bonding seriously and used copper braid to bond the doors, hood, hood, and rear hatch to the main body.  However, realizing that all of the doors should have a good ground by means of being bolted to the body, I haven’t yet bonded the doors on the MINI This SEEMS logical, but I don’t know – I welcome your insight and feedback here.  I did add a beefy ground cable from the antenna mount to the rear hatch sheet metal for a better ground.

AB1DQ Mobile operating position – the control head for the FT891 looks like it was designed for its placement on the MINI R56 speedometer, and the Alinco DR735 control head fits neatly under the ignition key slot. Yeah, I splurged for a Heil mobile microphone too!

HOW DOES IT WORK YOU ASK?

So far, so good – I have made some initial HF contacts on 40M along the east coast and into Nova Scotia, have checked into ECARS on my morning errands, and I have also participated in the local Meriden Amateur Radio Club Tuesday Night 10M net.

I’m pleased so far with the performance, but I have discovered that the ATAS antenna tunes slowly – I may need to beef up the ground connection on the lip mount – and of course it’s placement is far from optimal. I may try some of my ham sticks left over from my first mobile installation with a mag mount on the roof to see how it compares. So far I’ve not noticed significant alternator/engine noise on receive, nor have I received any audio reports indicating whine on my signal. I did notice, however while transmitting on 10M, it causes the LCD screen built into my rearview mirror to flutter. 

The bottom line is I’m quite pleased so far and look forward to making any necessary tweaks going forward as I make more contacts with my motorized MINI go-kit!

EPILOGUE… WHAT ELSE DID I DO TO MY MINI?

I mentioned that I did several upgrades/mods to my MINI Cooper this summer, besides the radio mods detailed above. In addition to the radio projects outlined above, here’s a list of the additional things I did to “Hubert,” my 2012 R56 MINI Cooper this summer…

I installed a Rockville RW10CA 10″ 800 Watt Slim Low Profile subwoofer in the trunk. I had underestimated the size of the subwoofer. Despite the words “slim” and “low profile” in the product description, I discovered it did not fit under the front seats, as originally planned and it occupied a lot of the limited available trunk space. My solution was to make it easily detachable and removable using PowerPole, RCA and RJ11 connectors.

I upgraded the horn. The car came with a very “un-MINI” trumpet horn set, and one of the two horns wasn’t functioning. I replaced the anemic horn with a FARBIN Loud Car Horn Super Tone 12V High Tone/Low Tone Metal Twin Horn Kit. Not only is it louder and grabs more attention, my MINI now has a more appropriate “meep-meep” horn sound.

I installed a pair of Wipac 5 1/2″ driving lamps. I always liked the way auxiliary driving lamps looked on both the classic and new MINI. I saved a significant portion of the cost by choosing Wipac over MINI lamps. The MINI lamps are expensive and make use of a proprietary mounting bracket that will not accept other manufacturer lamps.

I also attempted to upgrade the headlights. Like many MINI R56 owners, I felt the OEM halogen lamps were too weak. I purchased a set of aftermarket extra-bright LED low/high beam bulbs. The bulbs were simple to install, however the new LED headlights flickered incessantly. Apparently this is a fairly common occurrence that can be resolved by adding a resistive ballast to the circuit. I purchased a plug and play ballast set but was saddened that it did not completely resolve the flicker issue. So I’m back to the OEM headlights for the time being.

HAPPY MOTORING & 73 DE AB1DQ!

The Murania “One Transistor” Boy’s Radio Kit

INTRODUCTION & CONSTRUCTION

The Four State QRP Group (Oklahoma – Kansas – Arkansas – Missouri, in case you were wondering), founded in 2003, is one of the best developers and retailers of high quality and reasonably priced QRP (low power) ham radio and other do it yourself electronics kits.

I have a few of their kits over the past few years, most recently including the Bayou Jumper Paraset transceiver last year. I presently have the NM0S 4S-Tuner/Antenna Coupler kit on order.

Tonight I tackled one of their popular new non-ham radio kits, the Murania, a one transistor Tuned Radio Frequency (TRF) AM broadcast band receiver kit. The kit was designed by NM0S, David Cripe, who has engineered several of the 4SQRP kits.

The documentation for the Murania tells of the advent of transistor radios in the 1950s and how radios with 1 or 2 transistors were considered toys and therefore not taxed like radios containing more transistors. These 2 or less transistor “toy” radios became known as “Boy’s Radios” and are highly collectible today.

The designers of Boy’s Radios employed some creative design techniques to maximize the performance of these minimalist circuits, with sometimes amazing results. The Murania kit was inspired the design of those simple high performing transistor radios.

Unpacking the Murania kit.

My Murania kit arrived quickly within 2 days of placing my order online….WOW!

The Murania features a unique construction technique called “Pittsburgh Construction” developed by W0MQY , Joe Porter, in which components are soldered to the surface of pads on a silk screened double sided PCB.

Like other 4SQRP kits, the assembly manual needs to be downloaded from their website. Documentation is very good with clearly expressed step by step directions, but lacks pictures which might be helpful in illustrating potentially confusing steps for the newbie builder, such as the correct orientation of a polarized component such as an LED, diode or electrolytic cap.

The 4SQRP website suggest the kit can be built in about 2 hours time, and that was my experience. The radio is built in five stages… (1) wind the coil, (2) build the voltage regulator, (3) build the audio amp, (4) build the RF circuit, (5) final assembly.

1. Winding the Coil

The first task is to wind the coil which consists of 37 turns of No. 22 AWG enamel wire around a ferrite core. The instructions call for covering the core with a layer of masking tape first and using masking tape to hold the first and last winding in place.

My first attempt at
winding the coil.

I chose to use black electrical tape, and that was definitely a mistake – the electrical tape made it difficult to compress each winding snug against the previous winding and it didn’t do a very good job of holding the first and last winding in place.

I believe this may have also affected performance of my radio (see below). I am planning on modding the set and rewinding the coil with 61 turns (also, see below) and will use the recommended masking tape at that time.

2. Voltage Regulator

The first circuit constructed is the power supply/voltage regulator which consists of installing the volume control pot and attached power switch, one electrolytic capacitor, the battery connector, another capacitor and a resistor and the LED which serves three functions – power on lamp, signal strength indicator, and voltage regulator delivering 1.6 – 1.8 +VDC to power the radio.

I appreciated that the instructions called for testing the voltage regulator circuit before proceeding on to the audio amp stage. My Murania was putting out 1.792 VDC+ within the acceptable range of 1.6 – 1.8 volts.

3. Audio Amplifier

The Murania has a single stage of audio amplification based on the 2N3904 NPN transistor that drives the speaker through a matching transformer.

Other components in the stage included a pair of capacitors, a single resistor and of course, the transformer and speaker.

4. RF Stage

The bulk of the RF work is handled by a single IC, the TA7642, which has its origins in the late 1960s. Equivalent to the ZN914 and MK484, the TA7642 contains ten transistors and performs the task of RF amplification, audio detection, and automatic gain control. The documentation points out that with the TA7642, it is possible to construct a Tuned Radio Frequency receiver with useful sensitivity and selectivity, using only a handful of components and that this device served as the basis of many radio receivers that were the successors to the Boy’s Radios.

The 10 transistor equivalent circuit of the TA7642 per the datasheet.


Like the voltage regulator and audio amplification stages the RF stage went together without a hitch. All parts in the kit were properly identified and clearly referenced in the assembly manual. The etching on the circuit board made mis-installation pretty much an impossibility if you’re paying attention to what you’re doing.

The assembled Murania TRF radio ready for testing.

5. Final Assembly

After testing the radio to make sure it works (it did), the last step was to assemble the rest of the cabinet which is comprised of five additional pieces of yellow PCB material with pads strategically placed to match up for soldering to connect.

The pieces fit together perfectly, although I should have taken time as recommended in the directions to file off burs and rough spots so the pieces fit together more perfectly. Overall this is a pretty ingenious way to build a radio cabinet.

PERFORMANCE AND MODS

I was very pleased that the radio worked right away. I was able to pick up several AM stations with ease. Stations received were clear and the audio, while not as loud as I would have liked, was not distorted.

One problem I did encounter that is worth mentioning is that after I tested the radio on my bench I attached the back to the radio and brought it to my wife to show off my handiwork.

She was impressed, however when she turned the radio on, the LED lit up but there was no sound coming from the speaker – absolute silence – UGH!

I took the back off and quickly diagnosed the problem – the top of the 9V battery was shorting the speaker terminals – a problem easily fixed with a piece of electrical tape across the speaker terminals.

I did expect the radio to be a little more sensitive than it was initially and I realized that the radio’s performance might have been inhibited by my sloppy coil winding.

The unmodified Murania Schematic ©NM0S, 4SQRP Group

Online I found a list of three simple mods for the radio published by Jim Marco, WB2LHP in MI, the third of which that involves additional windings on the coil so I thought I’d give them a try.

Here are Jim’s mods…

1. Detector Gain Control…

FLOAT the wiper lug of R3 and place a jumper between the PADS for the R3 wiper and the high side of R3.

Lift the leg of R1 that intersects with R2 and R3 and connect a jumper between the floated leg of R1 and the wiper of R3.

According to Jim, this allows R3 to control the gain of the detector stage in the TA7642 acting similar to a regen control where there is both volume and gain reaction. The audio amp runs wide open and R3 should be adjusted for the best sounding audio.

2. Reduced audio distortion…

Changing R2 from 1K to 2.7K biases the output stage of the TA7642 for linear operation.

3.Frequency coverage and dial mapping…

Increasing L1 from 37 turns to 61 turns and removing C8 centers the frequency coverage and makes the dial tracking spot on…

The revised schematic based on WB2LHB’s mods

I am pleased to say that the mods were easy to accomplish and I had no difficulty with any of them. I did not have a 2.7K ohm resistor on hand so I tied a 2.2k and a 470 ohm resistor in series for R2. Using the recommended masking tape instead of rubbery electrical tape on the ferrite rod made a world of difference too – winding the 61 turns was a snap.

My modified Murania – notice the new ferrite coil, the replacement of R2, the removal of C8 on the right, and the jumper going from R1 over the speaker to the VR R3.

And how did it work? Even better than before – the radio seems to be more sensitive and is picking up more stations and the audio is definitely more crisp as promised. If you’re looking for a fun one-evening project that will take you back to your earlier days of melting solder – the Murania TRF receiver is worth building.

©2019 JMSurprenant

Alec Bradley Nica-Puro Rosado Gordo

I stopped by the Owl Shop after work today, a chilly late January Monday, with the Alec Bradley Nica-Puro Rosado Gordo in shirt pocket.  The cigar was a gift from my brother in law, Liam, who shares my love of cigars.  Liam and I have enjoyed several sticks together after family gatherings and the conversations have always been as good as the smokes.  Liam and I are both fans of the Alec Bradley line; I have never smoked the Nica-Puro before.

The Gordo is a hefty 6.2” 60 ring gauge cigar.  As the name suggests, this is a Nicaraguan puro – a Nicaraguan double binder and core of long-fillers from Nicaragua’s 3 main growing regions — Jalapa, Condega, and Esteli — are wrapped in a handsome Nicaraguan Rosado leaf.

Appearance is a nice oily chocolate brown, the Rosado wrapper is smooth with a couple of small veins and no seams.  Construction was very firm, with some softness noticeable just beneath the beautiful double-band.  The triple cap was impressive.

The cold draw was very flavorful.  Delicious notes of dried fruit, spiciness and some cedar.

The first third started off with strong notes of cedar, pepper, earthiness and some cocoa and nuttiness.  The burn was excellent, and a perfect draw.   The ash was salt and pepper and firm – and didn’t break off until about the inch and a half mark.

By the start of the second third, the flavor became creamier with continued strong notes of cedar, nuttiness and pepper.  There was a hint of leather and some cocoa.  The burn continued to be perfect throughout the second third.

Final third became creamier and the cedar and pepper notes continued right to the end and the burn remained perfect.  The cigar needed no touching up and never became bitter or stale tasting.  The smoking time was an hour and forty minutes.

The AB Nica-Puro was about as good as a cigar can be.  I would score it a 10 out of 10, a rating I don’t give often – but this is a true classic.

Recapping “The Glendon” RCA Victor Model 6-XD

At the 2018 New England Antique Radio Club Radio and Vintage Electronics Show, I had the good fortune of winning not one, but two door prizes!

The first was a circa 1955 RCA Model 6-XD-5A “The Glendon” AM broadcast receiver.  The radio was promised to be ‘operational’ but ‘not restored.’  The second prize was a coupon to WJOE Radio, a favorite local vendor for radio restoration parts who also attends the NEARC Show each winter. I used the coupon to stock up on a couple of capacitor assortment boxes realizing I could use the capacitors to recap the Glendon at some point.

That “some point” came just two months later in April when after listening to the radio for just about an hour and a half I heard a loud sizzling sound, followed by a loud “pop!” and then loud buzzing from the speakers.

Sure enough, upon opening the set up I discovered that one of the wax capacitors, No. C11, on the power line had exploded.

The failed C-11 capacitor.

A lot of folks are under the misimpression that when restoring old radios, the number one problem is that the old tubes have gone bad and that finding replacements is hard and expensive.  The truth of the matter is the absolute number one affliction that antique radios suffer is failing capacitors.  Replacement caps are plentiful, and inexpensive and many radios can be brought back to useable life by just recapping the set.

Over time wax and paper capacitors fail and the dielectric in large filter caps either dries up has leaked out.  A capacitor that fails appears in circuit as a resistor and will not block DC while allowing AC signals to pass as they should.  A sure sign that caps have failed in vintage radios is the presence of a predominant loud hum on the audio output.

Replacing capacitors is generally straight forward and easy.  It’s simply a matter of removing the old capacitors and replacing them with modern day equivalents.  Many times, you can easily read the values off the old capacitor once it is removed, but it’s also always a good idea to download a copy of the schematic and work from that.

BEFORE
AFTER

There are two values you need to be concerned with when replacing capacitors – the capacitance value and the voltage rating.

Capacitance is measured in farads – typically microfarads (MFD) or in picofarads (pF).  1 farad is equal to 1,000,000 microfarad, or 1,000,000,000,000 picofarad.

It’s always good to work from a schematic diagram – I found the schematic for this radio on the Radiomuseum.org website – the troublesome C11 is highlighted above.

When replacing capacitors, an exact match for the capacitance value is seldom critical, especially when working with consumer grade AM radio circuits.  If you are unable to find a replacement cap with the same value, it is generally o.k. to use a close or higher value capacitor in the circuit.

You can also combine capacitors together to create a capacitor with the proper value.  The math is simple – if you connect capacitors in parallel, their value equals the sum of the individual capacitors.

C1 + C2 + Cn in parallel = Ctotal

The second value you need to be concerned with when replacing capacitors is the voltage rating which is often abbreviated WVDC (working voltage, direct current) on the capacitor and on the schematic. Always be sure to replace capacitors with new units that are rated at the same working voltage or higher.

So, returning to The Glendon, I replaced C11 and all the other wax capacitors.  I noticed that the previous owner had replaced the electrolytic filter caps already.  The schematic called for a 30 MFD and a 50 MFD filter cap.  The previous owner installed a pair of 450 volt 47 MFD caps so I left well enough alone.

The “Dead Soldiers” removed from the set.

Sure enough, my recap job brought this fine old radio back to life and it spent last summer as my chair-side radio on the front porch for Red Sox games.  And what a year it was for listening to Boston baseball on the radio!

RCA VICTOR CO., INC. MODELN 6-XD-5C “THE GLENDON” SPECS:

Year: 1954/1955 
Tubes: 12BE6 12BA6 12AV6 50C5 35W4
Circuit type: Super-Heterodyne IF 455 kHz; 2 AF stage(s)
Tuned circuits:6 AM circuit(s)
Bands:  AM BCB only, 540 – 1600 kHz
Loudspeaker:  2 Loudspeakers / Ø 4 inch = 10.2 cm (not stereo)
Power out:1 W (1.5 W max.)
Material: Plastic
Dimensions (WHD): 12.5 x 7.5 x 6.375 inch
Antenna: Build in loop antenna
Power consumption: 35 watts.
Other: has audio input jack to connect Victrola record player.

©2019 JMSurprenant

Something new from AB1DQ

Hello and welcome to the new AB1DQ blog, I hope you find this site informative, inspiring and fun.

My name is James M. Surprenant and AB1DQ is my amateur radio call sign. I hold an Amateur Extra Class license and earned my first ticket as KB1IAR in 2002.

Although I came to ham radio later in life, I have always been fascinated with radio and electronics ever since I was a child ‘wasting time’ at my grandfather’s workbench.

My intent for this new blog is that it should be a place for me to share ideas of personal interest and projects that are currently on my workbench.

This is a personal site and like most persons, I’m not one dimensional. I have many personal interests including, but not limited to, photography, spirituality, cigars, whisky, baseball, poetry and music. Thus not all of the content here will be related to electronics and radio. I ask that all visitors here consume the content I share with an open mind, take what they need and leave the rest.

So, thank you VERY much for visiting – please drop me at ab1dq@protonmail.com and let me know what you think.

This “Cheshire Cat” is my ham radio logo and appears on my QSL card.
It was created by professional cartoonist and fellow ham radio operator N2EST, Jim Massara. Lear more about Jim and his work at http://www.hamtoons.net.

73 de AB1DQ
James
Cheshire, CT

Altar Q Cigar by Oscar Valladares

I smoked my first Altar Q cigar by Oscar Valladares a couple of weeks ago at a whisky tasting at the Owl Shop in New Haven, Connecticut.  It was my first cigar from Oscar Valladares, although I have been meaning to try their Leaf for some time.  The Altar Q impressed me with a lot of flavor that evening and I noted that it paired particularly well with the Laphroaig Lore Scotch whisky that was being poured.

It is noontime New Year’s Eve 2018 and I stopped in at the Owl again today to try another Altar Q. after running some year-end errands.

The cigar comes boxed in a wooden box of 16 with the cigars separated by paper. The cigars do not have a cellophane wrapper but instead have a beautiful wide 3.5” paper foot band honoring Mayan tobacco.  Currently Neptune Cigar offers the box of 16 for $168 which makes the cost of an individual stick $10.50 – a bit pricey for me, but really worth it.

Oscar Valladares Tobacco, is located in Danli, Honduras. It started operating on 2012, the Factory was founded by Oscar Valladares, Hector Valladares and Bayron Duarte, with experience in the tobacco industry; Oscar worked for more than 9 years with Rocky Patel and Bayron worked for more than 20 years for General Cigars and Oliva.

The Altar Q is a 52 ring gauge 6” cigar and features a Ecuadorian Sumatra wrapper, a Honduran Copan region binder and Honduran long fillers.  The appearance is oily and smooth, seamless with very few visible veins.  The cigar has a triple-cap and a pigtail.  Construction is fairly firm, and just a bit squishy.

I cut the cigar with my notch cutter and found the pre-light draw to be flavorful – very spicy, leathery, earth and classic tobacco flavored.

First third

Upon lighting, the Altar Q starts off with a big bite of spicy pepper – wow.  Also notable from the get go are subtle citrus, slight honey notes and some nuttiness.  The draw is very good and the burn is decent, a little uneven and required some slight touching up.  The cigar produces good smoke and produces a nice solid salt and pepper ash.

Second third

The strong pepper flavor is yielding a bit to a nice nutty and citrus flavor at the start of the second third.  The draw and burn both continue to be very good.  Just beyond the mid-point the flavor is becoming nuttier and the creaminess begins, however, the cigar needed re-lighting at this point, just as my first Altar Q needed a couple of weeks ago.

Final third

The last third begins with more creaminess, some nuttiness and the ever-present pepper.  The burn remained good and even and the draw was perfect.  As I smoked my way through the last third, the flavor became more and more creamy – a very tasty and satisfying smoke.

Overall

I consider the Altar Q an instant classic and a new favorite.   It pairs exceptionally well with a smoky peaty scotch such as Laphroaig Lore or a hot pot of Lapsong Souchong tea. I would rate it a 9 out of 10 and I look forward to picking up a full box before too long.

© 2019 James M. Surprenant