If one looks at the schematic there is a JFET buffer between the IF and the IF out in the main RX. Isolation and impedance matching is its function. There is no stock IF out for the subrx and hence no JFET.
JFETs have really high input impedances. A one resistor "gain mod" is on the K3 site reduces the signal loss in this JFET stage for those using the IF output jack. 73 de Brian/K3KO On 10/31/2012 21:10, ab2tc wrote: > Hi, > > I have absolutely no dip in the center of my LP-Pan display and I have never > heard anybody else having this problem either. The IF out port and the > crystal filter bank are driven in parallel by a buffer amplifier that > appears to be capable of driving both without gain loss due to the crystal > filter load. > > AB2TC - Knut > > > Edward R Cole wrote >> I built my K3/10 and installed the KRX3 with no issues of different >> audio levels. >> >> BTW running both Rx with dual LP-Pan on MAP65v2.3 sw shows the audio >> level on a bar graph for each (when in diversity mode). >> >> Two things were recently done to improve use of the >> LP-Pan: 1) Enabling an open filter position in the K3 and KRX3 >> eliminates gain "suck out" by roofing filter which is connected in >> parallel with the IF output jack. It shows as a dip in gain on a >> panadaptor spectrum display at center freq. 2) Installed 32.860 MHz >> xtal in LP-Pan which is 4x the IF freg of 8.215 MHz which eliminates >> the previous +6 KHz freq. off set in the display sw (thanks to Larry, >> N8LP). >> >> My 2m-eme dual-polarity adaptive receive system will get a work-out >> in this weekend's eme contest. It extensively uses the dual-Rx >> diversity reception mode of the K3. >> >> 73, Ed - KL7UW > > > > > > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/KRX3-insatall-tp7564774p7564863.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > 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 message. > Checked by AVG - www.avg.com > Version: 2012.0.2221 / Virus Database: 2441/5365 - Release Date: 10/31/12 > > ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2221 / Virus Database: 2441/5365 - Release Date: 10/31/12 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
