Design Decisions in the High School Direct Conversion Receiver.docxDesign Decisions in the High School Receiver Project.Why we did it this way. document - 15.29 kB - 05/29/2023 at 13:10 |
|
|
TJ DCR PO Worksheet - BOM.xlsxDCR Bill of Materials - quantities for 15 complete receivers with sparessheet - 19.19 kB - 04/25/2023 at 11:41 |
|
|
TJ DCR Mixer Build Instructions.docxBuilding the Mixer - Step by Stepdocument - 1.17 MB - 04/25/2023 at 11:36 |
|
|
TJ DCR BPF Instructions.docxBuilding the Band Pass Filter - Step by Stepdocument - 707.71 kB - 04/25/2023 at 11:36 |
|
|
TJ DCR Audio Amp Instructions.docxBuilding the Audio Amplifier - Step by Stepdocument - 1002.77 kB - 04/25/2023 at 11:35 |
|
|
Schematic - Band Pass Filter-.jpgSchematic for the 40 meter band pass filterJPEG Image - 76.26 kB - 04/25/2023 at 11:34 |
|
|
Schematic - Double Balanced Mixer.jpgSchematic for the double balanced mixer / product detectorJPEG Image - 98.01 kB - 04/25/2023 at 11:31 |
|
|
Schematic - Full DCR.jpgFull Schematic for 40 meter direct conversion receiverJPEG Image - 454.07 kB - 04/25/2023 at 11:30 |
|
|
Schematic - Audio Amplifier.jpgSchematic for the audio amplifierJPEG Image - 140.01 kB - 04/25/2023 at 11:30 |
|
|
Schematic - Oscillator and Buffer-.jpgSchematic for the permeability tuned oscillator and bufferJPEG Image - 110.08 kB - 04/25/2023 at 11:30 |
|
|
TJ VWS Building the Oscillator Instructions.docxBuilding the Oscillator - Step by Stepdocument - 604.36 kB - 04/25/2023 at 11:26 |
|
|
Winding a Toroidal Transformer (Video).docxWinding a toroid is often a "show stopper" for many prospective builders. But we wanted the students to have the experience. So we had them wind their own. This video shows them how. They did very well, and will no longer fear toroidal transformers!document - 12.07 kB - 04/25/2023 at 10:36 |
|
|
N3FJZ Build of Receiver.docxAt our request, many hams around the world built and tested the receiver. Rick N3FJZ was one of them. Rick did an especially great job of testing the circuit.document - 12.29 kB - 04/25/2023 at 10:34 |
|
|
TJ DC RX in a Simulator.docxDuring our preparation, we built the entire receiver in the LTSpice simulator. To our surprise, the ENTIRE RECEIVER (including the oscillator) fired up in the simulator. This allowed for some really robust testing. And it was great fun to see our creation working both in the simulator and in the real world.document - 12.71 kB - 04/25/2023 at 10:31 |
|
|
Atoms to Amperes.docxWe recommended some outside reading. Many of the concepts (like "hole flow" in a transistor) could not be covered in the short lecture period we had. So we recommended two books.document - 134.43 kB - 04/25/2023 at 10:30 |
|
|
Instructor's Lessons Learned.docxAs is usually the case, the instructors learned too! Here are some notes on lessons learned by the instructors.document - 16.29 kB - 04/25/2023 at 10:28 |
|
|
My receiver doesn't work.docxThe students must learn that new electronic projects don't always work the first time they are powered up. Here we anticipate problems that the students may face when trying to get their new homebrew receivers working.document - 13.71 kB - 04/24/2023 at 23:38 |
|
|
Mods for TJ DC RX.docxHere we encourage further experimentation and modification, going stage-by-stage.document - 15.96 kB - 04/24/2023 at 23:36 |
|
|
Possible mods to TJ DC RX oscillator..docxA possible modification to improve the tuning of the receiver. Students are encouraged to experiment and modify the receiver.document - 15.20 kB - 04/24/2023 at 22:14 |
|
|
TJ DC RX Final Assembly.pptxHere the students are shown how to integrate the four boards they have built, and how to connect a simple antenna. The students are encouraged to FINISH their project and to avoid having it end up unfinished on the dreaded SHELF OF SHAME.presentation - 2.23 MB - 04/24/2023 at 22:07 |
|
|
TJ 4 AF Amplifier.pptxThe audio amplifier was the most complex board and was built last. Three common emitter AF amps. By this point students were just grabbing schematics and were quickly building the circuits using Manhattan board techniques.presentation - 4.13 MB - 04/24/2023 at 22:01 |
|
|
TJ 3 Mixers.pptxThe mixer is at the heart of a direct conversion receiver. Students built their own diode rings and used transformers produced in Hyderabad India by our friend Farhan VU2ESE. This added soul to the new machine! We added a diplexer.presentation - 2.97 MB - 04/24/2023 at 17:20 |
|
|
TJDCRX Board 3 BP FILTER.pptxStudents build a bandpass filter, and then tested and adjusted using a NanoVNA.presentation - 1.42 MB - 04/24/2023 at 17:16 |
|
|
TJ DC RX 4 VFO Buffer.pptxAfter the oscillator, students added a buffer using a Field Effect Transistor.presentation - 424.36 kB - 04/24/2023 at 17:15 |
|
|
TJ VWS Class 1 Oscillator.pptxPresentation for the Oscillator Build. This was the first stage that the students built. This provided very early gratification -- when the students powered up the boards, the signals could be heard in a shortwave receiver (they were LOUD!) Woo hoo -- they had made radio frequency signals.presentation - 2.51 MB - 04/21/2023 at 10:39 |
|