Build from the base upward: The CHA UCM turns a sound table edge, rail, or similar support into a portable 3/8-24 antenna position and SO-239 feed-through. It is a clamp mount—not a tuner, transformer, loading coil, mast, or universal compatibility approval.
Deployment sequence
- Seat the clamp squarely on a clean, sound surface.
- Tighten until it cannot rotate, slide, or rock under firm hand pressure without using an extension bar.
- Load the antenna gradually while supporting it by hand.
- Strain-relieve the coax and recheck clamp tension after routing and after wind changes.
Before raising the antenna
- Use the isolated top 3/8-24 stud only with a documented radiator or feed unit.
- Attach ring-terminal counterpoise wires to the side screw when the antenna requires them.
- Banana-plug radial products need a separately documented banana interface; they do not plug directly into the UCM.
Before transmitting
- Confirm every mast section, clamp, mount, adapter, guy line, antenna attachment, coax route, and RF-return conductor.
- Begin RF checks at low power after the final geometry is stable.
- Record the exact configuration so a successful setup can be reproduced.
- Never use the temporary clamp on a moving vehicle.
- Add guying or secondary retention whenever the completed antenna requires it.
Use the current CHA UCM instructions.
