Here are a few links you may find useful.........

Club Log - a fantastic resource for DX'ers, general use and used by many DXpeditions.

Common mode chokes - by G3TXQ.....excellent information.

Portable Antennas - loads of information and tools to help you design and build your own antennas.

Reverse Beacon Network - a great resource for checking out band conditions, spotting DX, checking how well your signal is getting out......a must for CW ops.