There you go Jim shooting yourself in the foot straight off by referring your dB to power! > and I increase my transmitter power by 4:1 (6 dB)............ Of course the two entities voltage and power are mathematically related, but unless you say to what reference you are using, they can be somewhat meaningless. In the 17 years I spent in the Cable TV industry pre the advent of satellite technology, the dB was always related to voltage at 75 ohms and was understood to be so. The only occasion I remember using dB related to power was when using multiple phased antenna arrays to work out the total output as the gain was increased by a ratio of 3dB in power every time the number of separate arrays was doubled. With a sideways shift into telecoms for the last 20+ years I had to start thinking about dB related to power where 4 times gain or loss when related to power is 6dB as you say. The same 4 times gain or loss is 12dB when related to voltage as used in Cable TV. Irrespective of how the measuring systems for the two industries work, they are calibrated in dB relative to the system you are working with and as such are not directly compatible, thus making a reference when referring to dB gain or loss essential. Perhaps a topic to be discussed further off the Elecraft Reflector if needed. Bob, G3VVT _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
