CHA TDL Inverted Delta Loop Configuration

Lay the complete antenna out before extending either whip. A five-minute deployment stays controlled when the operator has already chosen the footprint, orientation, coax route, and lowering path.

The point is not to memorize one diagram. It is to select the documented geometry that fits the job and then preserve the parts that make that geometry a complete antenna.

What this means in the field

• One operator can normally assemble it in about five minutes after becoming familiar with the hardware.
• Below roughly 10 MHz, the low installation can favor useful high-angle regional coverage when propagation supports it. Above 10 MHz, the pattern becomes more directional, with the strongest response broadly normal to the loop plane.
• Rotate the hub or choose the site so the loop plane and intended contact direction make sense before raising the whips.

The complete TDL behind the answer

• The CHA TDL is a fast-deploying 3.5–54 MHz field system built around two fully extended SS17 whips, a 25 ft 4 in loop wire, a TDL Hub, a HYBRID-MICRO or HYBRID-MINI matching transformer, a spike, and 50-ohm coax.
• Inverted delta loop: the normal rapid-deployment configuration, with two SS17 whips forming the upper sides and the supplied wire completing the loop.
• Ground-mounted vertical: one fully extended SS17 becomes the vertical radiator and the supplied loop wire becomes the counterpoise.
• V-dipole or horizontal dipole: optional-mast configurations using both fully extended SS17 whips and the matching transformer at the feed point.

Band and matching reality

The published operating range is 3.5–54 MHz. The guide describes 10.1–54 MHz as the most effective range and requires an antenna tuner or coupler on 3.5–7.0 MHz. Installed SWR, site, geometry, feed line, and nearby conductors still matter.

Before you transmit

• Keep the complete antenna and coax away from overhead power lines.
• Choose a stable support and clear the area where people could contact a whip, wire, guy line, or feed line.
• Begin tuning at low power and observe the radio, feed line, transformer, and nearby equipment for RF feedback or heating.
• Review RF-exposure requirements and medical-device precautions before transmitting.

Make the next setup easier

Record the chosen configuration, transformer, band, tuner state, orientation, height, counterpoise or loop-wire route, coax, analyzer reference plane, and on-air result. That small field record is more useful than a remembered “good SWR.”