I would like to built a world band radio using tubes. Not just any tube radio but a high performance radio. I was thinking if i want to built from scratch better built a good one. Can any body help me?.

Ham radio magazines from the 40s thru 70s sometimes ran articles on homebrew receivers and design. In the US, QST would be the most likely source, followed by Ham Radio and 73 Magazine. QST, since it didn't pay for articles, tended to get esoteric ones describing one-off equipment. No one else would build it in the same way, but you can get some good ideas.

Unfortunately there are no good indexes: the best for this purpose would be "From Beverages Thru Oscar: A Bibliography" by Richard J. Rosen. It has 18 pages of references to "receivers" in all the ham magazines up to 1978 (and there is a 1979-81 Addendum). This won't get all the RF-design articles but is a good start. This used to be available in printed form and on microfiche but I do not know if it still is (his wife was selling it through a company name I have now forgotten, from New Hampshire).

Hi,
By "Hi Performance", are you looking to have high sensitivity, high selectivity, the ability to recieve sideband signals, etc.

By "World Band"- Are you looking to have a reciever that covers from 540KHz through 30MHz, or just a section?

ARRL handbooks prior to 1979 published plans for numerous radios, some more involved in than others, but most are capable of far more than you may realize. Even the small simple regenerative designs have outstanding performance when coupled with a suitably long wire antenna.

One thing to keep in mind, and this works as a general rule of thumb for almost any radio- "It is better to have a high performance antenna system, than it is to have a high performance reciever". The reason is simple; you want to have an antenna that will resonate at those small/distant signals, as well as effectively getting that signal to a reciever. If you do not have adequate signal strength from the antenna, your hi performance amplifier will be amplifying a lot of ambient noise that will usually prevent any small signals from being heard.

Also- use good headphones.

You can make numerous regenerative designs that use plug-in coils, and while these are simple in their construction, when attached to a decent antenna, you will pull in many small signals that a heterodyne style of reciever will not. They do require a certain amount of patience to get used to tuning, but due to their lack of a local oscillator for heterodyning the small signals, they are a very quiet reciever to listen too- however, if you bump them, they can develop their own oscillations and cause some interference. They are very selective, very sensitive, and can recieve sideband signals- part of the signal gets fed back to the tube, so continuous wave and sideband signals are able to be heard.

Otherwise, if you are looking for high performance with some level of complexity, take a lok at some of the various circuits that were used by various Ham Radio manufacturers in the thirties through the sixties at this site:
http://bama.sbc.edu/

A few other things that you will find to be of great help to improve reception- assuming you have a good antenna- even 75 feet or more of wire strung as far above the ground as you can; Wave rejector traps to attenuate strong local signals, And a method of switching different inductances into the antenna system (antenna matcher), and running a ground referenced counterpoise opposite the direction of the antenna, with a decent 52 Ohm Coax for signal feed.

: I would like to built a world band radio using tubes. Not just any tube radio but a high performance radio. I was thinking if i want to built from scratch better built a good one. Can any body help me?.