On Thu,12/29/2016 3:07 PM, Bill Johnson wrote:
Having "only" 5 watts doesn't change the need for proper termination and antenna match.
By proper termination, I think you're thinking about SWR and a match to the transmitter. This thread is several days and 20+ posts old, but I think I remember that the intent of the original poster was for portable operation. But I could be wrong. :)
There are two reasons for low SWR and "matching." One is to get the transmitter to provide power to the transmission line. If the mismatch is too high, the transmitter will "fold back" (reduce its drive to reduce its output power) to protect itself. Providing that match is the function of an "antenna tuner."
The second reason is to reduce loss in the line due to a mismatch. The SWR in a transmission line is determined entirely by the match between the antenna and the line. It is NOTHING to do with the match between the transmitter and the line. In typical QRP portable setups, transmission lines are rarely long enough for loss to matter, so the match between the antenna and the line usually doesn't matter. And the antenna tuner takes care of match at the transmitter so that the output stage can supply its full power.
73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
