AA3SJ
Homebrew and Construction Techniques / Suggestions
Caveat: I am not an expert, just a hobbyist. Listed here are Ugly and Manhattan construction techniques that I have learned over these few years of my homebrew career. Just some hints and tips that I find useful. Probably none of these ideas are new to the "homebrew masters."
Soldering Hints
*Buy a quality soldering station. After frustrations with soldering pencils bought at a local store, I finally broke down and spent some cash on a good station. The ability to vary the soldering iron's temperature helps prevent over-heated components, and decreases frustration when trying to solder components to the ground plane where additional heat is often needed.
*Use good quality solder. I highly recommend Kester solder, and stock of a few sizes, .020 for fine work, .040 for general soldering, and larger solder for jobs like coax connectors.
*Tin just about every wire or component before it is soldered into it's final position. This helps to achieve a good joint, and also assists in getting the components into position and keeping them there. Sometimes you will feel like you need three hands, but a small "blob" of solder on the lead of a resistor removes the need for the builder to hold the soldering iron, the resistor, and the solder all at the same time. Be careful with semiconductors when doing this so that they are not overheated.
*Take time to inspect each joint and to re-solder if necessary.
Ugly / Manhattan Construction Tips
*Change your standard of aesthetics. Ugly construction need only be "ugly" by name. I try to keep components in perpendicular and parallel lines where possible, but this is not always convenient.
*Think through your project carefully before starting. How large will your copper clad board need to be? Will you be trying to fit the project into a specific enclosure? Where will the controls be located? Could stacking two or more boards help conserve space?
*Most of the time I follow the schematic from left to right or right to left, using a board that I know is oversized. This prevents me from running out of space. The board can be cut after the project is completed, if necessary.
*Only when you are certain that you know the final layout of your project, and only then, apply a drill bit to the enclosure front or rear panels.
*I prefer to use axial components wherever practical. I bought a stock of .1 and .01 axial ceramic capacitors for bypassing and coupling. They make very convenient standoffs for other components and are very small units. Wes, W7ZOI, recommends using large value resistors, e.g., 1 Meg or greater as standoffs, although I haven't done this very often.
*Place your VCC strip near to the location where it's input jack and related on/off switch will be located.
*If you are using Manhattan pads, fill the pad with solder before you place components on it. And remember it only takes a dab of super glue to hold the pad in place. (I find that the gel version of super glue is easier to work with.)
*Sometimes I use the "AA3SJ Version" of Manhattan construction. Instead of using glued on pads, I dremel small squares in the ground plane. This is especially practical with smaller circuits where one can lay out the entire circuit before building it.
*Use a small tweezers to hold components in place while soldering.
*For sensitive components use small alligator clips as heat sinks.
*Finally, leave enough room between components for easy voltage testing and troubleshooting, and for easy removal of the component if you make a mistake.
Building a Junk Box
*As you progress you will find that certain components are used in just about every project. I found it necessary to stock some of these so I wouldn't need to order common components for every project.
*With every project, as you put together your parts list, order several extras of all but the least common things. In this manner you can build your junk box and have a spare part in case you accidentally destroy something. I once dropped my only T30-2 iron powder core on the cement floor of my workshop. It shattered into a dozen pieces and I needed to wait a week for an order of one torroid core. Frustrating!
*
Here is a list of the components I recommend keeping on hand (I keep each type of component and each value separated for easy retrieval in storage bins):
.1, .01, and .001 uF Bypass Capacitors
10, 22, 47, 100 uF Electrolytic Capacitors
A set of NPO Capacitors for VFOs, etc.
A set of Silver Mica Capacitors for Low Pass filters, etc.
A number of small Trim Caps
A number of Air Variable Caps as well
A complete set of Resistors up to 1 Meg (with extra 100 ohm, 1K, 10K)
1K, 5K, 10K, 100K Potentiometers
100 ohm, 1K, 5K, 10K, 100K Trim Pots
J310 FET Transistors
1n4401 NPN, 1n4403 PNP Transistors
Several RF Transistors for Transmitter PA Stages
1n4148 General Purpose Diodes
9.1V, 12V, 33V, 43V Zener Diodes
5V and 8V Voltage Regulators
LM386, 741, NE555, SA612, MC1350 ICs
SBL-1 Double Balanced Mixers
A variety of LEDs
T50-2, T30-2, T50-6, T30-6 Iron Powder Toroid Cores
FT37-43 and FT37-61 Ferrite Toroid Cores
#22, #26, #28, #30 Magnet Wire (different colors are desirable)
Hook up wire (I prefer Teflon Insulated)
RG-174 Coax (Again, I prefer Teflon)
Double and Single-Sided Copper Clad Circuit Board
*Additionally you will want to have some hardware on hand: A Variety of standoffs, bolts, lock washers, flat washers, nuts, and sheet metal screws. Try to standardize sizes to keep it simple. I also stock a variety of small enclosures (always a hamfest item for me).
[I'm sure to have forgotten a few things here, and I have quite a bit more stockpiled than listed, but these components will form the heart of your junk box.]
