Coupler from 1.5 to 70 or 80 MHz

Coupler from 1.5 to 70 or 80 MHz

Published here are 2 couplers with a T94-2 and a T94-6.

The first coupler was build with a T94-2 in order to cover the whole HF spectrum + 50 and 70 MHz. It produced some good results up to 70 MHz. but not much higher.
The number of turns was 32 on a T94-2. For a complete building instructions (if needed) please refer to THIS article.

Few changes were made: Ground the coax directly to your connector. The toroid should be as close to the connector as possible. Thanks PA0WMX

Below are some measurements:

First the coupler with the T94-2 and its plots (below)

 coupler-kl

 

The coupling from 0-4 MHz (below)

coupling-0-4MHz-kl

 The Isolation (Isolation – coupling = directivity) from 0-4 MHz (below)

directivity-0-4MHz-kl

 The coupling from 0 – 100 MHz (below)

coupling-0-100MHz-kl

The Isolation (Isolation – coupling = directivity) from 0 – 100 MHz (below)

directivity-0-100MHz-kl

 

The same coupler build with a T94-6 Results are the same, it just goes a little bit higher in frequency.

Coupling from 0 – 5 MHz (below)

coupling0-5-MHz

The Isolation (Isolation – coupling = directivity) from 0 – 5 MHz (below)

directivity0-5-MHz

 Coupling from 0 – 50 MHz (below)

coupling0-50-MHz

The Isolation (Isolation – coupling = directivity) from 0 – 50 MHz (below)

directivity0-50-MHz

Coupling from 0 – 150 MHz (below) unfortunately not working on 144 MHz.

coupling0-150-MHz

The Isolation (Isolation – coupling = directivity) from 0 – 150 MHz (below)

directivity0-150-MHz

The finished unit

buitenkant