Hi Harry, Hope the info that follows will be useful. I have made some research of how to make the internal K144XV Elecraft transverter be useful in contests. Originally it was almost useless due to many parasitics all across the band even from S9 signals. The stronger – the worse and there were a lot of them even here in KN29AU. So in July, last year, during IARU R1 3-rd subregional VHF contest, the band was full of clones. HI HI.
Comparying the schematics of both internal and external Elecraft 144 transverters shows three major differences that could have caused the different dynamic performance of the internal one. Firstly - the usage of three diode switching components in the Front-End chain up to the ADEX mixer. Secondly - usage of MMIC instead of BFR96 in the LO amplifier stage. Thirdly - the K144XV PHASE LOCK BOARD Here are some findings and possible solutions. 1.Remove (do NOT install) the K144XV PHASE LOCK BOARD! In this case transverter is using just its own Xtal generator and spirious signals caused, possibly, by leakage from the synthesizer are gone. 2. Bypass the input diode T/R input switch by using separate receiving path. Remove the shorting block from pin1-2 of the P3 connector and connect separate coax to pin2 – RF, pin3 – ground. This requires adding some front-end filtering and RF relays in PA, LNA or wherever you like. (I would have prefer to get rid of all diode switching in RX RF path but have no idea of RF relays small enough to fit into K144XV box). I have tested this setup in September during IARU R1 VHF championship and compared to July's event it looked like day and night. -- 73, Victor Goncharsky US5WE/K1WE (UW5W in VHF contests, EO90WF in 2014) UARL Technical Committee DXCC card checker (160 meters). -------------------------------------------- On Sat, 5/3/14, Harry_Yingst via Elecraft <[email protected]> wrote: Subject: [Elecraft] Possible bad KREF or K144XV Ref Lock or ??? To: [email protected] Date: Saturday, May 3, 2014, 8:57 PM I have a recent K3 (2 months old) that has the KX144XV Two meter module and the KXV144 Ref Lock. Today I installed the KBPF3 and some filters. After installation I attempted to calibrate the TX Gain and it kept failing on 60 meters. Through testing what I found is that if I connect the KSYN3 directly to the KREF3 and not through the K144XV Ref Lock it will calibrate and appears to function correctly. I am let to believe that either the KREF board is not putting out enough signal or the KXV144 Ref Lock is loading the line to much. Has anyone else seen this issue? Thank you -- View this message in context: http://elecraft.365791.n2.nabble.com/Possible-bad-KREF-or-K144XV-Ref-Lock-or-tp7588457.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:[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] ______________________________________________________________ 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]
