Tom, Thanks for your comments.
I appreciate your taking the time to answer my posting. I have great admiration for you, having been in the 'biz most of my life www.radions.net/comrcial.htm . 73. TR, K6GC, the Great Circle Station in the State of Jefferson. http://www.ijpr.org/Page.asp?NavID=1033 ____________________________________________ At 09:58 AM 7/12/2010 -0400, you wrote: >>When the antenna is connected and disconnected the noise floor >>moves just barely. You can tell, but it requires a critical ear. > >That is too little. That is about how my K3 behaves on six meters on >SSB bandwidth! On the narrowest bandwidth you use, you should hear a >very well defined noise increase, several dB, going from a dummy >load to the antenna. > >>>A note about my antenna. It is a HyGain 5BDQ trap dipole and the >>>SWR on it is 1.2:1 into about 200' of LMR240. > >Since feedline loss and SWR in receiving is set by the receiver, SWR >in the feedline on receive has nothing to do with transmit VSWR >(where the antenna is the load). I've never measured the input >impedance of the K2, but it could be you have an impedance mismatch >between the K2 receiver and the feedline, which would result in >feedline losses aggravating the feedline loss problem. > >What the 1.2:1 SWR indicates is the antenna mismatch is around 1.4:1 >and feedline loss on transmitting is about 2.5 dB. > >I have no idea what the K2 looks like for SWR on receiving, but many >receivers I've measured are pretty far off 1:1 SWR. If the K2 looks >like a 2.5:1 SWR (which is a reasonable upper limit based on other >receivers I have tested), feedline loss would be 3 dB plus you would >have an additional .12 dB mismatch loss at the antenna (the source). > >Sounds to me like the K2 you have needs more sensitivity if a dipole >with 4 dB or less system loss won't firmly set noise floor. > >73 Tom ______________________________________________________________ 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
