Intro: Three Transistor Short Wave Radio
Step 1: Obtain Components Listed in the Assembly Manual Parts List
Review the parts list and obtain the components indicated. Everything but a few pieces of hardware are available on Amazon or can be obtained directly from the suppliers indicated at the bottom of the parts list.
Below are a few notes regarding the parts used for the radio:
- The transistors for the radio can be purchased from Amazon or Radio Shack (assuming they are still in business in your area). I highly recommend the excellent Joe Knows Electronics semiconductor kit. It includes the transistors you need for this radio project and over 150 different types of transistors and diodes for just $22. And it includes a set of documents that are really good reading for the beginner. Check out www.joeknowselectronics.com. You will not be sorry.
- The resistors for the radio can be purchased from Amazon or Radio Shack. Radio Shack has a good selection of 1/4W resistors in a big 500 piece bundle for about $15.00 if you have a store nearby. Joe Knows Electronics also has a nice 800 piece package of 1% resistors for $12.00 if you don't mind ordering online. Joe's is a really good and well organized kit even if 1% resistors are a bit of tolerance overkill for this radio project.
- I strongly recommend ordering NP0 ceramic disk capacitors from Mouser or Digikey as they will far outperform most anything you can get on Amazon. The Joe Knows Electronics capacitor kit is an extremely good buy for every other capacitor at 645 pieces for $13.00. Don't bother with Radio Shack for capacitor kits as they are mostly junk values you will never use.
- I purchased several crystal earphones from AmplifiedParts on Amazon and they work great despite the poor reviews. Whatever quality problem they had in the past seems to have been ironed out. The crystal earphone comes with a 1/8" mono phone plug so I added a 1/8" mono phone jack from Radio Shack. The phone jack is also available from various sellers on Amazon.
- The variable capacitor (and a lot of other rather old and interesting parts) can be found at Uxcell (via Amazon) which seems an unlikely domain for radio stuff but they do have a lot of radio stuff that's interesting. I've created a diagram of the variable capacitor here that will help you figure out how to wire it in the radio.
- The case for the radio I built is a Hammond 1591GSBK ABS Project Box from Amazon.com with a piece of vector breadboard cut to fit on the top and spray painted with high temperature automotive flat red. I like the look of red on black, and the red color of the breadboard matched the red color of the original pbox kit. It's completely up to you how you want to house and color the kit you build.
- The knobs I used are Radio Shack knobs I've had in inventory for decades. Use anything you think is cool that will fit on the pot/varicap shafts.
- You will need to be creative on how you mount the variable capacitor on the vector board. I used a piece of 1/32" sheet metal cut to size with a Dremel tool grinding wheel and then drilled the holes to mount the variable capacitor with a power drill. Then I bent the end of it 90 degrees to form an L shape.
- You will need to be creative on how you mount the tuning knob to the variable capacitor. The shaft on the varicap is only about 1/4" long so you will need something to extend it. I found a plastic cylinder with a hole drilled through it that was about 1" long at my local Ace Hardware store. They have a really nice selection of odd hardware that is very useful.
- The 2-position barrier strips are available from Amazon or from Radio Shack in a pack of four. These are a great value at the price so if your local Radio Shack hasn't yet been turned into a Sprint cell phone shop you should definitely buy all of the packs on the peg. I know I did.
Please Note: I have no business relationship with any of the above vendors. Nothing of financial value was exchanged for my recommendation. None of the above vendors provided compensation of any kind during the creation of this project. I will not be compensated in any way if you choose to build this project or purchase components from any vendor I recommend. I simply had a good experience with the vendors I recommend and believe you will too.