Dave Richards AA7EE

September 17, 2016

A Single Lever Paddle From QRP Guys

When building the SST for 20M, my plan was to kit it out with a paddle, battery, and an easily deployable antenna, and head for the hills. That’s still the plan. I don’t operate portable very often, preferring the comfort of the operating position in my small apartment, where I can make as many drinks and snacks as I want, and do it all with the company of my 3 kitties. Bliss! However, having just made a small, lightweight CW rig, I have to take it out in the field at least once in order to prove it’s mettle.

Currently, the only paddle I have is a Bencher, which is a bit too heavy and cumbersome to carry in my backpack for a portable set-up. There are some really neat portable paddles on the market, but I didn’t want to spend much, so settled on the idea of making one from PCB material, inspired by Wayne NB6M’s paddle, and KI6SN’s version, which was based on Wayne’s design. Two things happened to stop that idea in it’s tracks though. The first was that, nearing the end of building my SST, I was beginning to feel a bit lazy. Occasionally, when wading my way through a scratch-built project, I ponder how nice it would be to build a kit and give my brain a rest. At around the same time, I came across the website for The QRP Guys and realized I’d hit paydirt. They have a selection of small and low-priced kits for the QRP’er, including some small paddles made from PC board for very affordable prices. Perfect! The QRP Guys are Chuck Adams K7QO, Doug Hendricks KI6DS, Ken LoCasale WA4MNT, John Steven K5JS, and Dan Tayloe N7VE. Holy moly – that is some serious QRP starpower. I think we’d all be well advised to keep an eye on what these guys are up to.

QRP Guys ship out once a week on Wednesdays. With any small ham business such as this, where the owner/operators have many other things going on, setting expectations is an excellent idea. I decided on a single-lever paddle, and ordered it over the weekend. Later in the week, a small bag of parts arrived in the mail –

QRP Guys provide a scale for you to gauge how easy or difficult each of their kits is to build. On a scale of 1 to 5, with 5 being the most difficult, this paddle kit is rated as a 4. They do mention that some kits may also be rated as requiring what they term “expanded skills” – meaning, I assume, more difficult than 5. The rating of 4 for this kit makes sense. The PCB paddle parts need to be positioned fairly accurately. The way to do it is with a light tack solder in one point, re-adjusting until the exact positioning is reached, at which point you can commit with fully soldered joints. There are quite a few small screws, washers, and other small parts, so care, and a container to put all the small parts in are good ideas.

Here’s the final paddle. What a neat-looking little assembly –

A view of the underside –

This paddle is intended to be fixed to a panel, such as the side of a portable transceiver. I wanted it to be on a base, so decided to fabricate one from single-sided PCB material –

The cable is a cord from an old set of earbuds that came to an early end in the washing machine. It has a small molded 3.5mm stereo jack on one end, which is perfect for the task. It is held to the paddle base with a loop of twisted wire that threads through 2 holes in the base. At the point where it is secured, the cable was covered with 2 layers of shrink tubing. Luckily, the flexible wires in the earbud cord were insulated with heat-strippable enamel, so all that was necessary to remove the insulation was a generous gob of solder on the tip of the iron, and a few seconds, for the enamel to burn off –

You can’t see them, but there are 4 stick-on vinyl bumpers on the underside, purchased from the local Ace hardware store – the same type I used on the SST –

The copper is not lacquered, so if I take the same photo in a few months, it won’t look quite as shiny –

For size comparison, here’s the paddle with the SST20 and a pack of playing cards –

Despite the little stick-on feet under the base, I’ve found that the most comfortable way to send with this paddle is to hold it in my hand. This will work well for portable ops, when a suitable surface on which to place it might not be available. The lever is made from springy stainless steel. Doug Hendricks reminded me of an old tip for finding suitable flexible metal strips for making your own paddle, if you wish to do so. Just visit your local auto parts store and purchase a feeler gauge – the tool that is used for measuring spark plug gaps. It contains multiple flexible metal strips, of varying thicknesses (and degrees of springiness), so you can pick the exact one to suit your preference.

I experienced a small learning curve with this paddle. Firstly, I had never used a single lever paddle and secondly, I wasn’t used to the springiness of the lever, as most keys and paddles use stiff metal for the pivoting part. It doesn’t take long to get used to though. If you’re looking for a cheap and rugged paddle, this is a good value for the money. QRP Guys have both single lever and iambic paddles, with and without a base.

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February 10, 2016

The Muppet-Style Construction of John N8RVE

I have been meaning to write a post featuring the inspiring construction work of John N8RVE for almost a year now but sadly, am only able to think about one thing at a time, and The Sproutie MK II took up a lot of space in my head last year. Then, after finishing that, my one-track mind switched off from home-brewing and blogging activities completely. I am still unable to contemplate any more construction projects, and think that I may have done everything I set out to do with home-brewing, at least for a while.

In the meantime, there are a couple of things I’ve been wanting you to know about, and one of them is the excellent approach that John takes with his projects. John and I first became acquainted when he built a Rugster direct conversion receiver, and a WBR. Then I saw his build of a broadcast band regen, and that classic QRP design, Dave Benson’s SW+40, and really started to take notice.

John uses a form of construction that has been championed by Chuck Adams K7QO, in his QRP-Tech group on Yahoo Groups. Chuck calls it Muppet Construction and it refers to the practice of using an etched PCB, but soldering the components directly to the copper traces, thereby negating the need to drill holes in the board for component leads. It makes the process of creating the board easier, as there are no holes to drill. Also, after the circuit has been constructed, it is easier to look at the component side of the board and figure out what is connected to what – a process that is much harder with conventional through-hole PCB’s.

Back in January of last year, John finished construction of a broadcast band regen receiver, based on a design by Rick Andersen KE3IJ. Here is his very nicely etched “Muppet” PCB –

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BCB Regen Receiver (Photo courtesy of John N8RVE)

The board partway through construction –

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BCB Regen Receiver (Photo courtesy of John N8RVE)

And the completed regen (note the use of a rubber pinch wheel to achieve slow-motion tuning –

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BCB Regen Receiver (Photo courtesy of N8RVE)

John’s next project really caught my attention. It is the classic QRP design, Dave Benson’s SW40+. Dave has retired, and the SW40+ is no longer available as a kit (perhaps sometime in the future it will be again?) I’m sure there are many folk who would love to build a SW40+ but lament the lack of availability of a kit. Luckily, the kit manual, including schematic, is freely available online so the obvious answer is to build your own, which is exactly what John did. You could build it Ugly-style, Manhattan-style or, as John chose, Muppet-style. Here is his fully populated board –

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SW40+ (Photo courtesy of N8RVE)

Doesn’t this just look fantastic? This is very inspiring John!

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SW40+ (Photo courtesy of N8RVE)

Then, using the same technique, John built a HiMite 20. The HiMite 15 and 20 were next-generation QRP transceivers based on the Rockmites and, like the SW series of rigs, were the brainchild of Dave Benson. This is John’s version of the HiMite 20. When he first e-mailed me with news of this project, he was having some problems with the receiver. I’m not sure if he was able to solve the issues, but I think it looks great –

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HiMite 20 (Photo courtesy of N8RVE)

Just before his muppet construction odyssey began, John built a WBR, but ended up giving it to a friend who liked it. What to do? Build another one! This one is for the 31M broadcast band. John has had some issues with the volume level though otherwise, it is working OK –

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WBR Receiver (Photo courtesy of N8RVE)

One of the great things about developing the ability to scratch-build (as opposed to assembling projects from kits) is that you can pretty build anything you want, as long as you have the schematic. You can build it using any one of a number of techniques – Ugly Construction, Manhattan, Muppet, or any combination that you wish. You could even design your own PCB and take the drastic measure of drilling holes in it for component leads 🙂

Thank you for sharing the details of some of your projects with us John, and I hope they inspire some readers the way they did me!

 

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