Paul, I am not certain your test is entirely valid. If there is no atmospheric noise on the band you are using, you should notice no difference in level switching from a dummy load to an antenna.
The bandwidth of the receiver will make a great difference as well, and that is both the IF bandwidth and the front end bandwidth. The K2 does have the low pass filters at the receiver front end - some other receivers run with a wide open 'DC to Daylight' front end which will pick up more wideband noise. You are not necessarily comparing apples to apples with such a simplified subjective measurement. It would be much more informative to actually measure the MDS at a given receiver bandwidth and at the frequency of interest. Measurements of that nature should be controlled and can be used for valid comparisons. 73, Don W3FPR > -----Original Message----- > > Hi to all on the reflector. I'd like to put something out here and see > if others experience the same thing or if I possibly have a problem with > my K2 sn5834. Someone (I don't remember who) mentioned that a great way > to test receive sensitivity is to simply check for an increase in noise > level when switching from a dummy load to a resonant antenna on a dead > band (like 10m is lately), and I am a great believer in that method. I > have used it for years with various commercial and homebrew rigs. > So here's the deal. K2 set for 10 meters, preamp off, antenna is > resonant wire (and also used a beam). When switching between dummy load > and antenna, there is no (or barely perceptible) change in receiver > noise output. With the preamp on, the change is noticeable, as the > noise increases both with dummy load and antenna connected. What I'm > concerned about is the preamp off situation, as all other receivers I > have tested do show a marked change in receiver noise when doing > this test. -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.16.12/628 - Release Date: 1/15/2007 11:04 AM _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
