Ron, 2 reasons for the use of 1N5711 diodes rather than 1N4148 (or even 1N34A) - 1) the 1N5711s have been shown to produce a more consistent voltage over the frequency range than any of the others, and 2) the Shottky design has a low diode drop (the 1N34A does too) which will produce readings that are more correct at low powers (less than 2 watts).
With the KPA100 installed, the low power factor may not be a large consideration for you, so the 1N4148s could stay, but if the greater frequency dependency produces a problem, swap back to the 1N5711s. Yes, keep those antennas shorted when not in use and when thunderstorms approach. 73, Don W3FPR > -----Original Message----- > Hi, > The other night I left my K2/100 and KAT100 still attached to the > antenna, and we must have had a thunderstorm or the like pass through. I > had been using the rig before I hit the sack, and everything was > fine, but > in the morning I got the dreaded "Hi Cur" warning if I tried to transmit > anything higher than 10w. > Subsequent testing proved the SWR bridge diodes in both the KPA100 > *and* the KAT100 had changed from being diodes to short-circuits. A trip > to the local (dead loss) Electronics store to get some more 1N1755 diodes > produced 1 diode ! ( typical) > What's a bloke going to do with the Christmas postal rush in full > swing and > Elecraft thousands of miles away? > In the end I replaced the 4 diodes with common old 1N4148's and > everything > appears to be working fine......which brings me to the question......why > are the 1N5711's used anyway? does their being Shottky diodes > make them any > better in this application? > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.15/580 - Release Date: 12/8/2006 12:53 PM _______________________________________________ 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
