I offer a collection of 69 historical patents from wellknown company RCA, published between 1930 and 1975.
They are from USA or Great Britain (all in english).
The patents are busy in most cases with various (loud)speaker inventions (basket for a loudspeaker, magnetic structure for a loud speaker, stereophonic system).
All patents are complete, that means contain the full text and all drawings (see example). You will get a professional overview about historical patents of RCA loudspeaker technique, which you find nowhere in the world in this good quality / completeness.
Delivery is as a zipped file with a patent collection of pdf files (not printed, not a book). You need only the wellknown free programme Acrobat Reader or a similar one to open the files. You can also print each file.
Copyright of the patent collection has only the seller!
Shipping:
You can d o w n l o a d this patent collection after payment from an internet source. I will send the text of the link for d o w n l o a d i n g a zip-File of about 25 MB with the patent collection as message to the buyer via the ebay system. Please have a look at your messages in the "My ebay" modus or see your emails in your ebay email account, where the message to the buyer should also arrives. After d o w n l o a d i n g please unzip the file. Then you will get a data directory with the pdf - patent files. I will send the link not later than one day after payment. Then you have 10 days time to d o w n l o a d your patent collection of historical patents.