Component Info:

Capacitors:

      * "Jahre Kondensatoren & Induktivitäten", Germany: www.jahregmbh.de

     * "CDE" in South Carolina, US: www.cde.com

     * "Mouser Electronics" in Texas, US: http://de.mouser.com/Home.aspx

Teroids:

     * "Profi Electronic Kuhna", Germany: http://www.amidon.de/websho/stratoindex.html

     * "Amidon", USA: https://www.amidoncorp.com/

Here are some "Amidon" Ferrite-Teroids which I used for combiners, splitters and filters:         

I started to analyze a professional filter - the Hagenuk  LP Filter - here are some pictures:         

Here is a first home brew LPF designed for first measurements - not reliable for high power: