So does this mean that if I have a brand new KIO2 that L1 is large enough to handle the current of the KPA 100 and KAT 100 together? Or do I still need to wind an inductor like recommended by Don (W3FPR) and also found on the KK7P website to avoid "smoke" from L1.
Thanks, Brian N1WNC -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Steef PA2A Sent: Sunday, July 27, 2008 3:54 PM To: [EMAIL PROTECTED]; Mark Adams, PE Cc: [email protected] Subject: Re: [Elecraft] K2 I/O Module Help Needed Mark, I have had the same problem and also a hole in the 15 uH RFC. I replaced the coil temporarily by a resistor of 10 Ohms. Elecraft uses heavier inductors nowadays. 73 's Steef PA2A K2 4654 K3 1184 ----- Original Message ----- From: "Don Wilhelm" <[EMAIL PROTECTED]> To: "Mark Adams, PE" <[EMAIL PROTECTED]> Cc: <[email protected]> Sent: Sunday, July 27, 2008 2:53 AM Subject: Re: [Elecraft] K2 I/O Module Help Needed > Mark, > > I would bet you are using an externally mounted KPA100/KAT100 combination. > That puts a load on the 12CTRL line coming out of the K2, and yes oft > times L1 on the AUX board is overloaded and goes up in smoke. It is > usually OK with the KPA100 or the KAT100 alone, but the combination of the > two overloads that tiny inductor. > > You need to replace the inductor with one having a heavier current rating. > A toroid will do just fine. If you have one of those tiny cores like used > in the KSB2 RFC1 and RFC2, then just wind about 15 turns on that core. > Lacking that, use an FT37-43 core and wind about 12 turns on it (the FT-37 > core is a bit large and untidy when mounted on the AUX board, but it > works). The inductance is not critical. In fact, you probably can > temporarily substitute a wire, but there may be noise coupling between > your KPA100 and KAT100 at times, so I would not recommend the wire as a > permanent fix, but it can get you going until you can get a suitable > inductor. > > If you want a tool to figure the number of turns needed on a core to > produce a given inductance, I suggest you download miniRing Core > Calculator by DL5SWB - it is freeware for radio amateurs - see > www.dl5swb.de to download it. > > 73, > Don W3FPR > > Mark Adams, PE wrote: >> Hi Gang, >> >> On FD, my K2 I/O board went south. It just stopped working when contest >> time arrived Saturday. Bummer. I've just dug into the radio and found >> that I have no power to U1 or Q1 on the I/O board and that L1 on the Aux2 >> Board is busted. Has a hole in its side to be exact. So, my junk box has >> no 15uH inductors hiding anywhere. I have some inductors but no way to >> measure them. >> >> Anyone have any ideas? Is there a resistor I could sub to finish >> troubleshooting? Maybe a few turns of #18 tinned wire would do the trick? >> I cannot even find formulas to help me out. >> Yes, I'll order a few from the big E Monday, but until then...... >> >> 73, >> Mark K2QO >> >> > _______________________________________________ > Elecraft mailing list > Post to: [email protected] > 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 > _______________________________________________ Elecraft mailing list Post to: [email protected] 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 _______________________________________________ Elecraft mailing list Post to: [email protected] 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
