G4KWT - I use "RFsim99" quite a lot both at home and professionally. It is very easy to drive and has some useful tools for easily designing RF filters, matching networks

and attenuators. It can be found at 

http://101science.com/RFSim99.exe 

Free Schematic Capture and PCB Layout software:

I found this free schematic capture and PCB layout software very easy to use. It comes with a good library of ready made parts but you can very easily create your own custom parts as well. You can attach suppliers part numbers to components and print out bills of material. It won't generate a netlist but will allow you to print the schematic and any/all of the PCB layers.

http://www.expresspcb.com/ExpressPCBHtm/Download.htm


Patents online:

You can search for and download complete patents online at:

http://gb.espacenet.com/search97cgi/s97_cgi.exe?Action=FormGen&Template=gb/EN/home.hts

Try using the Advanced Search utility and type Marconi into the 'Applicant' field and 1901 into the 'Publication date' field. Scroll down the results list and you'll find the famous Marconi 'four sevens' patent concerning tuning (syntony) - patent no. GB190007777.

To download complete patents (PDFs) you'll need to click the 'Original Document' tab and then, on the next screen, select 'Save Full'.

Just how many Dyson patents are there?!!