Arahan Pembangunan Antena Loop AM

Anda mungkin sudah menerima rekaan statik dan penerimaan rendah di radio AM anda sebagai fakta hidup. Masalahnya bukan semestinya sinyal atau lokasi anda, tapi kadang kala antena radio itu sendiri.

Loop Antennas

A loop antenna is made of copper wire wound around a non‑conductive frame. The frame is usually a wooden X made by joining two 1‑by‑6 inboards. The wire is wound either in a spiral from the outer edge to the centre (spiral loop) or around the edges of the frame (edge‑wound loop). The two ends of the wire are connected to a 365 pF variable capacitor which tunes the antenna to the correct station frequency.

Membina Antena Loop Terikat Sisi

1. Take two 18‑inch 1‑by‑6 boards. Mark the midpoint on one edge, then mark two more points 3/8 in. to each side of the midpoint. This gives a 3/4 in. gap in the centre.

2. Using a square, mark a slot from each mark to the centre of the flat side. The centre is actually 2¾ in. from the edge.

3. Cut the slots with a small handsaw. Align the slots on the two boards and push the outer edges together until they reach the bottom of the slot. The boards now form an X‑shaped frame.

4. Make eight half‑inch deep slots, spaced ½ in. apart, on all four ends of the frame. Wrap 22‑gauge copper wire around the outside of the frame through the slots.

5. Mount the variable capacitor on the inside surface of the frame and solder the two ends of the wire to the capacitor terminals.

Penggunaan

Tune the AM radio to a station that has weak reception. Place the loop antenna on or beside the radio. Slowly adjust the dial on the capacitor while listening. Because the antenna is directional, once reception improves, rotate the loop from left to right to find the best signal.