How does the preselector know to peak up the RX signal and not also peak up the noise?
Dale W4OP > Rich, > > Yes the tuner acts as a preselector and peaks up the signal. > > Years ago I wrote W6AM a letter asking him if he used an antenna tuner > with his rhombic antennas. He replied that he did use a tuner but not so > much > to improve the impedance match to the rhombics for transmit, (he had them > tuned up pretty well) > but to act as a preselector to peak up the signals. He went on to > describe his > setup, using Collins 75A4 receivers and a Johnson KW matchboxes. He said > the > big Johnson KW matchbox, not the smaller one, was very effective at > peaking up the > received signal. I was convinced that the tuner was a a good thing to > have in line > for receive if he had receive enhancement using the tuner with his big > rhombics ! > > > Bob > K6UJ > > > > On Mar 28, 2011, at 11:05 AM, Richard Fjeld wrote: > >> For me, receive capability was an important factor, among others, in the >> decision to buy an Elecraft. The model is irrelevant to this post. For >> years, I have been studying comments made about receiving, as opposed to >> those who think a radio is 'good to the last watt'. Recently, there was a >> rather lengthy thread about whether a K3 user was having receive problems >> or not. I'd like to share an experience with the group. >> >> Over the years, I have used coax fed antennas and lived with compromise >> SWR figures. I wanted an all-band antenna so I recently changed the 80 >> meter dipole so that it is center fed with homebrew 450 ohm ladder-line >> to a tuner. I use an MFJ Matchmaker (TM) to 'tune the tuner'. While it >> puts out a white noise, I tune for minimum S-meter reading. When >> finished, a quick transmit reveals the SWR. >> >> One day while tuning close to optimum at the frequency I was on, and >> because I receive while I tune, I began to hear a weak CW signal. At >> first, I thought it had just come on frequency, but as I listened, I >> realized that the station had been in qso for awhile, but I didn't hear >> it until I reached optimum resonance with the tuner. I knew a resonant >> antenna was important, but I was surprised at the difference it could >> make in receiving. A good receiver is wasted if the signal doesn't get to >> it. >> >> >> Richard Fjeld, n0ce >> [email protected] >> I'd rather be learning. >> >> >> ______________________________________________________________ >> 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 > > ______________________________________________________________ > 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 -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.894 / Virus Database: 271.1.1/3535 - Release Date: 03/28/11 02:34:00 ______________________________________________________________ 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
