Well, that just sways me back to the 'I won't bother with a K1 (since I have a KX-1)' position and just get a K2 next (even if it is not quite a unquantifyable pure sounding as a K1). Thank you for the help in deciding (again).
dt . --- Mike Morrow <[EMAIL PROTECTED]> wrote: > David wrote: > > >I would like to setup a K1-4 for 30/20/17/15, which I believe would need an > LPF > >for 20 and 15). I believe I can do this with all of the parts that come > with a > >K1-4 except that I don't know if it includes an LPF for 20. > > As supplied, the K1 with KFL1-4 covers 40m, 30m, and any two of the 20m, 17m, > or 15m bands. It does NOT cover ANY four of the 40m, 30m, 20m, 17m, 15m > bands. Actually, K1 product literature claims that the KFL1-4 coverage is > 40m, 30m, 20m, and either 17m or 15m, but the KFL1-4 is actually a little > more versatile than that. I guess they thought no one would ever give up 20m > coverage. > > It has two LP filter sections in the transmitter output/receiver input signal > path. > > One LP filter section is switched in by firmware for the two lowest bands > (40m and 30m), with a filter cutoff somewhere above 30m but below 20m, where > the second harmonics of 40m operation would appear. > > The other transmitter LP filter section is switched in by firmware for the > two highest bands (any two of 20m, 17m, 15m), with a cutoff somewhere above > 15m but below 10m, where the second harmonics of 20m operation would occur. > > Thus, as supplied, the KFL1-4 won't cover 30m, 20m, 17m, and 15m because > you'd be trying to put 30m and 20m signals through the same LP filter that > cuts off below 20m. > > Additionally, it would be hard to juggle around the values of the fixed > capacitors in the pre-mix and the RF band-pass filters to accomodate 30m and > 20m operation for the firmware-programmed bandswitching relay latching action > that takes place for 30m and 40m operation. > > Of course, KFL1-4 firmware could be modified to select one LP filter section > for only one band (30m), while selecting the other LP filter section for the > other three bands (20m, 17m, 15m), but we don't have the option of altering > the KFL1-4 firmware. > > Your combo is not impossible, but it would take some study, BP/LP filter > redesign, and additional parts (fixed capacitors). But be careful. The K1 > has the best spurious output specs of any Elecraft rig, and re-design could > sacrifice that spec. > > IMHO, it would be best to choose a combo of bands that the KFL1-4 already > supports. Trading off 17m for 40m isn't much of a penalty. It gives you a > good night-time band any time of the year or solar cycle. > > 73, > Mike / KK5F > K1 No. 175 (Nov. 2000) > _______________________________________________ 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
