Unit 4 — Operating Procedures and Calculations
TM-GEAR-001 — Open Handout TM Chapters: Chapter 5, Appendix A ELOs: Install and operate the ANTENNA SWITCHES — MANUAL, MOTORIZED, AND AUTO-BAND correctly; interpret performance data; compute derived quantities Estimated time: 30 minutes (includes 3–4 practice problems)
Step 1: Read the TM
Open TM-GEAR-001. Read Chapter 5 — Operating Procedures and Appendix A completely.
Then come back here.
Chapter 5 Content
- Manual switch: rotate selector to desired antenna port before transmitting. Never rotate the switch while transmitting — arcing at the contacts can weld them.
- Auto-band switch: confirm CI-V address matches the transceiver's configured address (default 0x56 for IC-7300, 0x70 for IC-705). Monitor the CYD display to verify the switch follows band changes.
- Remote switch: send band command via RS-485 or Wi-Fi API. Verify LED indicator (or CYD display) confirms correct port selected before transmitting.
- Never transmit into an open switch port (no antenna connected) — reflected power will be 100%, potentially damaging the transmitter PA.
Appendix A — Reference Formulas
| Band | Freq range (MHz) | Default port | Notes |
|---|---|---|---|
| 160M | 1.800–2.000 | 1 | Inverted-L or T-antenna |
| 80M | 3.500–4.000 | 2 | Dipole or vertical |
| 40M | 7.000–7.300 | 2 | Shared with 80M |
| 20M–10M | 14.000–29.700 | 3 | Yagi or beam |
| 6M–2M | 50–148 | 4 | VHF verticals |
| 70cm+ | 420–1300 | 5 | UHF verticals |
Key Formulas Summary
Key mathematical relationships from Appendix A:
(See Appendix A in the TM)
Operating Notes
Chapter 5 specifies 4 operating steps.
Installation and operating discipline: - Always verify polarity and orientation before making connections — RF transformers and baluns are phase-sensitive - Route feedlines away from parallel conductors — parallel runs create mutual coupling that degrades isolation - Ground all exposed metalwork at a single chassis point — multiple grounds create loops - Record settings, frequencies, and power levels for every test — you need baseline data for comparisons
Practice Problems
Work these before reading the answer key below.
P4-1. Using the operating procedure from Chapter 5 and the formulas from Appendix A: State the installation steps you would take to put the ANTENNA SWITCHES — MANUAL, MOTORIZED, AND AUTO-BAND in service on a 40m (7.150 MHz) station. List steps in order.
P4-2. From Chapter 5: what installation or setup detail produces the best RF performance with the ANTENNA SWITCHES — MANUAL, MOTORIZED, AND AUTO-BAND? What is the tradeoff if you omit or shortcut that step?
P4-3. Chapter 5 specifies an operating procedure for a specific use case. State the first three steps of that procedure from memory.
P4-4. Appendix A gives a formula for computing a result from measured values. Pick one formula and compute a worked example using made-up but realistic values. Show all work.
Answer Key — Practice Problems
P4-1. Compare your list to Chapter 5. Steps should include: select mounting location → connect to feedline/antenna → verify polarity/orientation → apply power or signal → verify operation → record baseline.
P4-2. See Chapter 5. The most important installation detail is usually physical orientation, lead length, or ground bonding — the tradeoff if omitted is degraded isolation, increased SWR, or common-mode current leakage.
P4-3. See Chapter 5, steps 1–3. Copy exactly then close the TM and state from memory.
P4-4. See Appendix A for the formula. Your arithmetic is correct if your result has the right units and is physically plausible.
Checkpoint
Before proceeding: - [ ] You can state the operating procedure from memory (at least the first 5 steps) - [ ] You can compute the derived quantity from Chapter 5 / Appendix A without looking - [ ] You understand what a degraded or unexpected result tells you about the installation
→ Proceed to Unit 5