Hello , While I was waiting for my K3 to arrive, I have been doing some experiments with the Softrock Lite . The softrock lite is an amazingly good rx for its 11 $. I was interested in a panoramic display, so I tried it out on the TS-850 . With a 35.362 Mhz Xtal and Rocky software that was not much of a problem. It worked just fine. For the K3 , I ordered a 32.812 Mhz Xtal . I read here that more isolation is needed to prevent the oscilator signal ( 8.204 Mhz in my case) to go back to the K3. Someone suggested the use of a HCPL-4562 . First I measured at the input of the Softrock, with the TS-850 and found a strong S9 carrier at 8.204 Mhz With the HCPL-4562 in front of the Softrock, I was able to hear the carrier on the input, but no indication on the S-meter. That should be enough isolation, I think. Then I added an extra stage . I copied the schematic from the K2 preamp with a 2N5109 to give the signal from the IF an extra 14 db or so and extra isolation. I still could hear the carrier , somewhat quieter, and see nothing on the S-meter. The whole thing is built into a metal box and shielded between the different stages, and an extra shield between the HCPL-4562 input and output. The connection between the K3 and the adapter is a short coax cable with two bnc plugs. When changing from xfil1 to xfil2 and xfil3 on the K3, I noticed a shift in the display, so I made three different entries in the rocky.ini file: in the [Band] section I added : FL1=8625 FL2=9700 FL3=9630 I had to experiment with these values until the signal was at the zero mark on the scale . One important thing I overlooked was the fact that you need the KXV3 interface. It was only when I was building the K3 that I realised that... :) I have no special soundcard, I use the on-board soundcard of my pc. It works fine with Rocky, I haven't tried any other software ( yet ). 73 de on5ao
K2 #5237 K3 #0324 jo benoit ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs _______________________________________________ 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