Electronics Infoline Web

50MHz linear AMP

This machine has about 12dB gain. And, maximum power is 3 watts

http://www.intio.or.jp/jf10zl/50Mlinear.htm

50MHz PSN-TRX

using phase shift network

http://www.intio.or.jp/jf10zl/50MPSN.htm

WA3KEY presents everything you need to know about the Collins 51J4.

http://www.wa3key.com/51j4.html

http://www.techedge.com.au/vehicle/wbo2/5301.htm

http://www.hills2.u-net.com/electron/oscillat.htm#555

Applications of the most common IC timer chip.

http://www.ee.ed.ac.uk/~kap/Hard/555/aplications.html

Short Tutorial on the Classic Timer, the 555. With animations. Also many other circuits based on 555 chip.

http://courses.ncsu.edu:8020/ece480/common/htdocs/480_555.htm

An excellent extensive tutorial. Includes history, timing and logic diagrams. With numerous replacement guides.

http://www.uoguelph.ca/~antoon/gadgets/555/555.html

A nice 555 Timer Tutorials with good references.

http://www.williamson-labs.com/480_555.htm

This is a very commonly used IC for making simple timing circuits and oscillators.

http://homepages.westminster.org.uk/electronics/555.htm