2 elements Half Square antenna for 40 meters

2 elements Half Square antenna, 40 Meters band

@2025: Rebuild it using T94-6 toroids as switchable inductances instead stubs. This year, a 12-16 dB F/B ratio was observed. Will be fully tested in CQWW CW 2025.
@2024: Good value for a simple antenna. F/B ratio is not even a 6 dB, something is wrong. Due to terrain configuration, is somehow tilted.

Hardware

2o meters long.
2 elements, 6 meters apart.
11 meters above ground.
3 relay boxes.

Capabilities

Monoband
6.8 dBi @ 20 degrees
1.4 dBi@5 degree
1.2 SWR @ 50 ohms
j = 1.1 Ohms

Features

Easy to build
About 16 dB F/B ratio
Electrically instant E/W switching
No radials

CQ WW CW 2025 antenna modifications !

I had low results testing Front to Back ratio during CQ WW 2024.

For sure, the use of cheap low quality RG58 as coax stubs, did not provide needed inductance.

This time, I will remake it but using old school T94-6 yellow toroids and a junction relay box for each antenna. Hopefully, I will achieve much needed 16 dB F/B ratio.

Coaxial switch box

Ground sitting box, will switch TCVR coax toward East or West antenna

1'st element inductance box

If transmitting toward West, this box will add an inductor via relay switch to increase antenna electrical length.

2'nd element inductance box

If transmitting toward East, this box will add an inductor via relay switch to increase antenna electrical length.

Box 1/3 sitting on top of 1’st antenna. Western antenna has down coax connected when relay is off power while Easter antenna has a series inductance to act like a reflector. In both West or East cases, the choke balun is hosted in the same IP65 box as relay PCB is.