Self-Paced Course — K9AY LOOP ANTENNA — 40M
TM-ANT-040 — Open Handout TM-ANT-040 Estimated time: 2–3 hours (reading + practice + field lab) Handout: TM-ANT-040 (k9ay_loop_40m/tm.html) — keep it open throughout
What You Will Be Able to Do
TLO-1: Given the required materials and tools — construct the K9AY LOOP ANTENNA — 40M per TM-ANT-040, tune it to resonance, and verify performance meets the SWR and resonance criteria stated in Chapter 7.
TLO-2: Given NanoVNA or SWR bridge measurements — interpret resonance and SWR data, apply the required calculations from Appendix A, and determine pass/fail against the stated acceptance criterion.
Scope
This manual covers the K9Ay Loop Antenna — 40M for low-noise directional reception on 40M (7.0–7.3 MHz), useful 80M with retuning. This is a receive-only antenna. The primary performance metrics are front-to-back ratio, noise figure, and signal-to-no
What You Need
Handout
- TM-ANT-040 (K9AY LOOP ANTENNA — 40M) — open alongside this course
Equipment (needed for Unit 4 and Unit 5 labs)
- Materials specified in Chapter 3
- NanoVNA or SWR bridge
- Calculator
Course Units
| Unit | Topic | TM Chapters | Est. Time |
|---|---|---|---|
| Unit 1 | Theory of Operation | Ch. 2 | 20 min |
| Unit 2 | Materials and Construction | Ch. 3 | 20 min |
| Unit 3 | Assembly Procedures | Ch. 4 | 25 min |
| Unit 4 | Calibration and Tuning | Ch. 5, Ch. 6, App. A | 45 min (lab) |
| Unit 5 | Verification and Field Testing | Ch. 7 | 30 min (lab) |
| Final Assessment | 15-question written test | All | 20 min |
How to Use This Course
- Work units in order.
- For each unit: read the assigned TM chapter first, then read the unit, then answer the self-check questions.
- Self-check answers are at the bottom of each unit — try before looking.
- The checkpoint at the end of each unit is a go/no-go.
- Complete the Unit 4 and Unit 5 labs with a real antenna before taking the final assessment.
- Passing score: 13/15 (87%). All calculation questions must be correct regardless of total score.