Steve's Radio Page SW40+ Project

It all started as an idea to have a small transceiver that was inexpensive to show potential hams one way to get on the air. I then realized it had to be practical for me to use also. The Rockmites and Hi-mites are cheaper but more skill and patience is needed to get a QSO with them so I decided to go with a classic. I put my order in for one of Dave's 40 meter 2 Watt transceivers and knew I had to wait, so I started collecting the peripherals needed to complete the radio. The first item I procured was a touch paddle device from www.cwtouchkeyer.com. It was $18. I also got a plastic case for the radio ($5). Here is how I made the paddle.


I took a piece of 3/8" hobby plywood and glued with epoxy two 3/4" wide strips of .025 copper to it as shown. I used a paper cutter to cut the copper but there has got to be a better way.	This is after it was trimmed and sanded a bit.

This is the hole in the plastic case. I located it so that when the box will be upside down I can use the paddle with my left hand. The controls will be on the top of the case (the actual case bottom).	I had to epoxy the screw shaft so it would not fall out.

These two pictures show the practice fit.

Here it is epoxied in place and the tabs bent back.	Here I just finished polishing the copper with a Dremel tool.

Here I was christening it on the Flying Pigs net on 2/12/2006. Since I didn't have the SW40+ board yet, I wired it to my K2. This thing is great. Better than any paddle I have ever used.	3/4/2006 - I got the SW40+ kit from Dave a few days ago. Here I am working on the accessories. The three boards are epoxied together. The board on the right is the touch keyer board from www.cwtouchkeyer.com that I have been raving about. The board in the middle is a breadboard
	containing a PK keyer PIC chip from Jackson Harbor Press. Why the PK and not the PK4 or some other fancy chip? Because the PK chip makes dits and dahs, has a pot speed option, and is dirt cheap. I don't like changing keyer speed using push buttons and going through a menu. The two paddle signals from the right board go to the PK chip via the two white wires. The PK chip is powered by the 3.3 Volt regulator on the touch paddle board on the right. Eventually both boards will be powered by the power supply of the SW40+. This setup was connected to the key input to my K2 and works super. By the way the board on the left is a RIT board probably for a 40-40 transceiver design from the 1990s. To the left is the drawing for a layout of the controls. The pot on the right is the tuning pot. These pots will be mounted on the bottom of the box, and the box will be used in the upside down position.

Here is the finished radio. The pots are on the bottom, and most of the connections were made on the bottom of the board. The three utility boards are to the right, and the paddle is at the lower right corner.	Here is a view of the three utility boards. The tacked on red wire goes to the SW40 keying circuit.

The upper left pot is for paddle speed, the upper center is audio, the bottom pot is for RIT, and the one to the right is for tuning. I guess you can tell that I am left handed.	Don't laugh. This is my first try at a circuit board. I used DipTrace. This is for a touch key for the K2, using mostly SMD parts. The board is about the size of a quarter and only 3/4 inch wide.

So I went to Office Depot with an inkjet copy of the board and they copied it as dark as they could on their laser printer using the standard paper they had. I ironed it onto the board. I then went over it with a Sharpie pen.	I then etched it with about 7 grams of ferric chloride in 1 ounce of water. It turns out the laser toner worked better than the Sharpie ink. This board is quite usable. I can add some solder to the weak areas and it should be OK. The board is set up for 805 type SMT resistors and caps.
To the right is a close up. I used an LM317LZ regulator in a TO-92 case because I could not find a suitable surface mount regulator that was smaller. The 220 and 470 Ohm resistors (221 and 471) to the right are to adjust the LM317 to 3.91 Volts. The lands for the input connections are at the top above the 100K resistors (104). The output to the keyer is at the bottom and to the left of the two 3 terminal devices which are the 2N7000 switching transistors. And of course the QT113H ICs that do all the work are at the center. This board is going to become a very mini paddle for my K2 that clips onto the bottom bail. I have to thank Eric, KE6US, for ordering the parts for me. His KX1 touch paddle is at: http://www.ke6us.com/touch_keyer.htm .

Here I have cut a chassis out of 3/8 inch hobby plywood. The sides are circuit board that was etched for the paddles. One side is glued on. The board fits nicely inside. the receptacle is from a motherboard and is for a keyboard connector. The paddle should be exactly 1 inch high once it is sanded down.	Power and output wires are secured and potted in epoxy. The input wire going to the paddle surface is circled. This wire will go through a hole in the paddle surface and be soldered on the outside. At this point I gave up on the green keyboard connector.

These three photos show the working paddle. This one is one inch high. By making the circuit board longer and narrower, you can make one 3/4 inch high which is about perfect. I am using a 9 Volt battery now for power but will eventually plug it in to a future 12 Volt accessory jack at the rear of the K2. I just need to figure out how to attach it to the bail for left handed or right handed use. By flipping the unit over you can switch the dit and dah positions.

Now I just need a lightweight way of attaching it to the bail of the K2. Since the K2 bail is at an angle about a 10 degrees, a shim would be required to keep the paddle vertical.	So I am looking around in the garage for some kind of clamp and I find this thing. I could probably order one smaller. I clamped the paddle to the shelf at 45 degrees but vertical. I then added some JB-Weld to the end of the clamp, put it on the bail and pressed the two together. This should allow for the odd tilt of the bail. Will wait 4 hours to see. This assembly should be removable if I didn't get any glue into the threads of the removable pin at the front of the clamp. The blue grease might help to accomplish this. If they made this clamp in one-half this size it would be perfect for this type of application.

The JB-Weld worked really well. The clamp is at the exact angle needed.	Works great. With 1/4 inch less height and a 50% smaller clamp it would be perfect.
This version of the board is only about 5/8 inch high. So with this board the paddles can be made about 3/4 high which is about a perfect dimension for them.