Phase 1: The Noodling Effect


A term I use frequently is to "noodle" a project --that is to think a great deal about the project before I start soldering wires or cutting metal. The "effect" of the noodling is to have a far smoother project with less hiccups, twists and turns. In essence it is a process to clearly understand what you are doing before you do it. The Bitx40 is no exception! Clearly being a fully assembled board with all of the adjunct hardware the very first temptation is to "let her rip" and that usually results in a blown board! The odds of that happening go up by 100 if you have never built anything. But a successful build can be done even by the novice if you only take the time to noodle.

Getting started involves preparation and completely following the steps outlined below:


Step 1. Become familiar with the circuit and the individual elements. The hookup pictorial is critical to having the right wires in the right place. The builder should be so familiar with this drawing to the degree that you can see it in your sleep. The cables can only be installed on the board in one direction but it is then other end that is the problem. For instance the hot side of the antenna jack is correctly mated with the plug on the board but if on the antenna connector they are reversed then there is a good chance you will smoke the final as the RF output will be shunted to ground. Fifteen minutes of study is not enough!!!!! Fortunately VU2ESE has provided a color pictorial of the wiring. Print this out and USE IT as a guide when doing the final wiring.
Step 2. Prepare for the build by starting with the right tools. Those cheapo rusted screwdrivers from Harbor Freight should be replaced with a good quality flat head and phillips screw drivers. A good set of needle nose pliers and nippers are high on the list. I bought a Craftsman pair of electronic nippers ~ about $8 at Sears. The spring mechanism failed and I returned them to Sear's and walked out with a new replacement pair --free. Try that at Harbor Freight. You know why it is called Harbor Freight? Also on the list is a grounded soldering iron with a fine tip and good quality Digital Voltmeter (DVM) such as the ExTech series from Jameco Electronics. Long term a Digital Storage Oscilloscope (DSO) and Signal Generator/Counter such as the Feel Tech should be acquired. Oh pretty simple stuff --get a headband magnifier those surface mount parts are small!
Step 3. Work Space. Have a decent work area with adequate lighting! You cannot build the project on your lap and stay off the kitchen table! The workspace should be such that you can leave the project as is and come back later without anything being disturbed. Lighting is really important and I have several task lights that can be placed right over a project. You would be amazed how such a simple device can improve your circuit building by a factor of 10.
Step 4. Make a cardboard template of your main board ~ approximately 5 inches square and templates of other key pieces. Get a pad of 1/4 inch graph paper (Staples) ! With this graph paper you can do a sample layout of how your pieces will fit in the enclosure that is chosen. The quad pad can also be used to lay out the front panel as to where various controls would be located. The paper template prevents wear and tear on your board and precludes possible damage when the main board slips from your hands and falls on the floor. There is a bonus here! When you use the quad pad paper for the panel layout and you are satisfied with the arrangement --BOOM the layout can be taped to your front panel and it then is a drilling template to drill your pilot holes. Yes you always use a 1/16 inch bit to drill pilot holes!

Step 5. Other Hardware! While the rig comes complete with virtually all controls, wiring, board mounting hardware and even the microphone element and PTT switch, you will need more stuff. Thus you need to develop a shopping list of other goodies. the list below is for the rig as supplied using the varactor tuned VFO. Later a list will be added to include the Arduino and DDS plus LCD (Liquid Crystal Display).

Enclosure: K6NE used a box from Jameco that is roughly 7X6X5 and is value priced. N6QW used an available 6X10X2 aluminum chassis. The chassis bought new is twice as expensive.
10K audio taper pot w/a 1/4 inch shaft. The kit comes supplied with a pot and attached power switch. But this pot has a non standard shaft which also means you will need a mini-toggle SPST power switch. This switch is from All Electronics. For the 10K Pot see Jameco .
Two knobs ~ these can be from Radio Shack both should have 1/4 inch openings and one should be larger than the other. Knob 1 and Knob 2.
DC Power Cord. Chassis mount female and male plug are included in the kit but the buyer must furnish the DC power cord. Use Red Black size 14. Get a chunk from All Electronics
Hardware. Purchase two sizes of 4-40 bolts (1/4 and 3/8 inch long) and a like quantity of 4-40 nuts. Jameco 1/4 Jameco 3/8 and mating Jameco Nuts

Threaded Pillars. Get ones with a 4/40 thread and sizes ranging from 1/4 to 1/2 inch long. These are available on eBay. Also get some terminal strips Radio Shack.

Consumable Supplies. 60-40 solder, solder wick and 4 inch long cable ties.


Step 6. Recheck your plan. Employ the 24 hour rule. Do nothing for 24 hours --this will save you a lot of grief! No drilling! No Soldering! Nothing --as you will find in that intervening period you thought of something you didn't think of previously!