Subject: So You Want to be a Builder, Huh? Part 4
Date: Mon, 12 Aug 2002 22:30:09 -0700
From: "Doug Hendricks" <email@example.com>
To: "Low Power Amateur Radio Discussion" <qrp-l@Lehigh.EDU>
This is part 4 of a series of articles that I am writing on how to become a builder of qrp ham radio gear. I plan on going from a rank beginner to advanced projects and giving suggestions on how to become a good builder. This installment will cover a couple of projects that are very important station accessories, a set of PC Board Paddles, and the NorCal BLT Tuner.
First the paddles. I have a good friend, Dave Gauding, NF0R, who loves to build simple gear. He has messed around with building simple paddles for as long as I have known him. He also has a set of very nice Brown Brothers paddles, yet he continues to experiment because he likes to build, and it gives him pleasure to build a project and have it turn out. When Dave saw the PC Board paddles on the NorCal page, he told me that they were the real deal and worked surprisingly well for such a simple idea. The key to the paddles is that it uses PC Board for the arm of the paddle, nothing new with that, but the unique thing is that the board is given more flexibility by drilling a hole in it. Check out the drawings and pictures on the NorCal page and you will see what I mean. Here is the URL:
Wayne McFee, NB6M, designed these single lever paddles, and they work brilliantly. The NorCal page has a full set of instructions on how to build them, all that you need is some double sided PC Board and a good iron. I use my soldering station and turn the heat up to 850 degrees and it works fine. You can also use a Weller soldering gun, which will provide plenty of heat. One of the things that often happens in ham radio is that one guy will come up with a good idea, and someone else will improve it. That happened in this case. Carel Mulder, PA0CMU decided to make a set of iambic paddles using Wayne's method, and he was very successful. Here is the URL to see the double lever iambic paddles.
Carel even shows you a simple way to put silver contacts on your paddles. This is a neat one evening project, and when you finish, you have a nice set of paddles to use with your station. Seabury Lyon, who lives in the Northeast, showed me a neat trick at Lobstercon. Seab likes to use something called poster stick, which is also called blue tack, to hold his paddles on his rig. Gives it a nice solid base, it doesn't move around, and is always handy. You can buy it at Staples or any office supply store. And, just in case you are wondering, that is ribbon cable being used as a cord for the paddles. Another "freebie" and a great idea. The neat thing about this project is that it is almost free to build. One hint, be sure to use steel wool to polish your pc board before you solder it. It works a lot better that way. Also, when you have to drill holes in small pieces it is better to drill the holes first, then cut off the piece from the larger piece. No kit is available for this one, so you get to scrounge the parts yourself. Ask around at the next radio meeting for help in finding the parts, or better yet, go to a swap or flea market and look for old relays and double sided pc board pieces. If you live near a PC board fabrication shop, ask them for their waste pieces and they will be glad to give you all that you need.
The next project is the NorCal BLT tuner which is a bargain at $25 + $4 shipping and handling from me. Here is the URL on this project:
This tuner was designed by Charlie Lofgren, W6JJZ, who is the world's leading authority on Z-Match tuners. I asked Charlie to design a simple tuner that would work on 40 meters for a talk that I was going to give in Ft. Smith, Arkansas at Arkiecon, and he came through with the BLT. When it was tested with a 44 ft. doublet, we found that it worked on 40 through 10 meters, not just 40!! What a deal. I designed the case, which comes with the kit, and the case is one of the reasons that I picked this kit to be part of this series. You will learn how to build good, solid cases out of PC board material. The parts come precut, all that you have to do is assemble them. Plus, the kit is not built on a board, it uses Manhattan style construction, which uses small pads glued to the circuit board as tie points for the components and the board itself for the ground plane. You just follow the schematic and build as you go. Very easy to do, and it frees you from having to build only projects that have a board. The kit goes together easily in one day, and when you finish, you have a QRP tuner that will handle up to 10 watts. The name BLT stands for balanced line tuner. This was designed to be fed with twin lead, ladder line, tv lead, any balanced line. But you can have a long wire and coax tuner too just by doing a simple mod. Put another BNC connector on the back of the tuner. Place a wire from the center conductor of the new BNC to one of the binding posts on the back (on the inside of the tuner of course). Then mount a SPDT switch with one side going to ground, and the other to the other binding post. Now, when you want to use the coax tuner or a long wire, simply throw the switch and ground the binding posts. Throw the switch back to use as a balanced line tuner.
Plus, the tuner comes with a built in dummy load/SWR Indicator designed by Dan Tayloe, N7VE. The Indicator uses an LED that will go out when the best match is made and SWR is lowest. Pretty neat idea, and it works great. Also, the kit comes with a very nice Lexan cover which were made by Dennis Foster, KK5PY. They really set off the tuner, and I love the "look" it gives it. You will like to show it off to your friends, and you won't need to take off the top to show it to them. Neat idea, thanks to Dennis for coming up with it, and making all of those covers.
The two projects in part 4 will give you some more building experience, and teach you how to mount connectors, solder wires, do point to point building, and gives you a start on a great, tool, the Manhattan method of building. Hope you enjoy the series, and I encourage you to keep building and learning. Part 5 will be our first serious rig. It is a single band transceiver, and it comes with VFO and is a classic kit. You will enjoy it.
72, Doug, KI6DS