CHA TACYAGI-70 Product DNA and Intended Use

Why this matters in the field

Its value comes from portable directional gain and front-to-back discrimination, not from universal compatibility with every mount, radio or service.

Use the antenna the way its geometry was built to work

The current guide documents a 13.7-ounce, sub-18-inch folded three-element UHF Yagi with 7 dBi published gain, greater than 15 dB front-to-back ratio, a 100 W rating, and less than 2.5:1 SWR across 400–470 MHz. In the field, that advantage still depends on element order, full extension, direction, polarization, mounting, and UHF feed-line loss.

Use this sequence

1. Step 1: Confirm the exact operating frequency.
2. Step 2: Read the newest guide.
3. Step 3: Identify required cable and adapter.
4. Step 4: Choose handheld or mounted use.
5. Step 5: Set polarization.
6. Step 6: Perform a low-power field check.

Read the result—not just one meter

• Change one important variable at a time and restore the baseline before the next comparison.
• Separate what was observed from what was inferred. Signal level, decoded quality, impedance, SWR, audio reports and error rate are different measurements.
• Repeat the test. A result that cannot be reproduced should be recorded as provisional rather than turned into a general rule.
• Use the lowest practical test power and preserve screenshots, analyzer files, photographs, radio settings and location notes.

The shortcut that causes trouble

Treating the broad physical frequency range as permission to transmit anywhere within it. This shortcut hides the limiting subsystem and can create an incorrect repair or operating conclusion.

TACYAGI-70 is UHF, not VHF. Its physical frequency range does not authorize transmission on every covered frequency, and a 1/4-20 camera thread or adapter-supported 3/8-24 path does not make every support structurally interchangeable.