This is a updated collection of easy to build projects for radio amateurs and swl's. See all my projects in the OLDER POSTS down this blog.
Have fun.
73' John

Mutual respect is the key to global peace.....

Saturday, July 29, 2017

Antenna switch .

By means of a Apem DPDT on-on 15A toggle switch a reliable 100 Watt HF antenna switch can be made with 2 advantages.
1: the switch points to the connected antenna.
2: the non connected antenna is grounded.
The picture shows the switch from behind.

Monday, July 17, 2017

IC-7300 preselector idea.

The IC-7300 has a signal overload problem. A preselector can be an option.
L1 - T80-2 .  L2 - T68-6 .  L3 - T50-6 .  T1 - T2 are 1:9 transformers. By adding a 470pF capacitor to ground between T2 and the polyvaricon the overall swr drops to a verry acceptable levell.

Disclaimer:I'm not responsable for any damage due to improper reproduction of my projects.