Hi all, The KFL1-4 module needs trimmers that are both wide range and extremely temperature stable, due to the high loaded Q of the band-pass filters. To emulate this stable capacitance with trimmers now available, you'd have to use a hand-selected C0G cap in parallel with a much smaller trimmer for each of the original 16 trimmers. This would be extremely tedious for builders. So, while it is possible, it is not practical.
Wayne N6KR ---- http://www.elecraft.com > On Mar 6, 2015, at 8:33 PM, Don Wilhelm <[email protected]> wrote: > > The part number for the bare KFL1-4 board is E100129 as listed in the KFL1-4 > manual. > > I do not know whether Elecraft has any boards in stock, but one could ask. > Good luck with your project(s). > You would also need the firmware E610010 as well as the other parts such as > relays, connectors, crystals etc. If you downloaded the KFL1-4 manual before > it was removed, you are 'in luck'. > > 73, > Don W3FPR > >> On 3/6/2015 10:03 PM, Dr. William J. Schmidt, II wrote: >> There is probably some middle ground here to satisfy most people in this >> situation. It's completely understandable and correct that Elecraft would >> not want to spend the effort to re-engineer this board. However some of us >> on channel don't see the task as rocket science and in most cases would be >> glad to provide that expertise as a side effort just to make that equipment >> useful. If Elecraft had even something as simple as unpopulated boards to >> purchase for use as prototypes, it would make that task quite simple. >> >> >> Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ >> >> Owner - Operator >> Big Signal Ranch - K9ZC >> Staunton, Illinois >> >> Owner - Operator >> Villa Grand Piton - J68HZ >> Soufriere, St. Lucia W.I. >> Rent it: www.VillaGrandPiton.com >> >> email: [email protected] >> >> -----Original Message----- >> From: Elecraft [mailto:[email protected]] On Behalf Of Don >> Wilhelm >> Sent: Friday, March 06, 2015 8:05 PM >> To: Ross Primrose; Phil Wheeler; [email protected] >> Subject: Re: [Elecraft] K-1 4-band Availability/Status? >> >> Ross, >> >> That vital part is the availability of the 1 to 40pF trimmer capacitors >> - which also had a very tight temperature compensation characteristic. >> The KFL1-4 used 16 of them. >> Due to their wide capacity range, the same capacitors could be used in >> all 16 positions and provide successful tuning. >> Those capacitors have been discontinued by the manufacturer. >> >> The problem is that there are no substitutes that could be used for all >> 16 positions, and it would take a great deal of engineering effort to >> determine the suitable substitutes for each position on the 4 band >> board. In other words, would a 3 to 15pf trimmer be suitable in the C1 >> thru C4 locations and would a 12 to 30pF trimmer be suitable in the C5 >> thru C8 locations and so forth. Furthermore, if the 17 meter band were >> chosen instead of the 15 meter band, which low range trimmer capacitors >> would be used for each band. >> I am speaking of examples for the engineering effort that would be >> required to select the best capacitor for each position and each band >> choice. It is not a trivial exercise. >> >> I certainly would not want to do experiments to select the appropriate >> replacement trimmers necessary to resurrect the 4 band board, and I am >> certain the engineering staff does not have the time to do that work. >> The documentation would get more complicated as well - for example, "if >> you have chosen the 15 meter band, use the red trimmer capacitors at >> location Cx but if you have chosen 17 meters, use the yellow trimmers at >> those locations" >> >> Hopefully you get the point of the complexity created by those wide >> range trimmer being no longer available. The values I have proposed >> above are only numbers off the top of my head for examples, they have no >> value in the real world. >> >> 73, >> Don W3FPR >> >> >> >>> On 3/6/2015 6:46 PM, Ross Primrose wrote: >>> Looking at the parts list, I can't imagine which part is no longer >>> available.... >>> >>> 73, Ross N4RP >>> >>>> On 3/6/2015 4:37 PM, Phil Wheeler wrote: >>>> Confirm. Something related to a vital part(s?) no longer being >>>> available. >> ______________________________________________________________ >> 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] > > ______________________________________________________________ > 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]
