The stock HC4/5 elements (non Elecraft versions) in their basic form produce a minus 65 db output. This is sufficient for use with some rigs other than an Elecraft. I use them straight with my IC-746Pro without a preamp. The Heil items sold by Elecraft for the K2 has a built in preamp that boost their output to a minus 40 db. To power the preamp, +5vdc is needed on the "AF" line between the K2 and the mic element. The K2 should have the higher level (-40db) to attain full SSB modulation. BTW, the numbers above came directly from Bob Heil in an email exchange between he and I.
When saying one gets good audio reports doesn't mean that your K2 is fully modulated. It just means there is no noticable distortion to the listener. The actual received signal could be one to three "S" units difference between the elements with and without the preamp and without SSBA and SSBC adjustment in the K2. That is something similiar to adding a 200-500 watt amplifier to your K2. Yes, it is worth it to have the correct level output from your microphone. I use a preamp with my non K2 mics when using them with the K2. I got the preamp schematic from Don Wilhelms website. (He offers tremendous troubleshooting advice here on this forum.) The site URL is http://w3fpr.qrpradio.com/ I built a separate +5vdc regulator supply for the preamp using +13.8vdc from my Astron SS-30M power supply for my K2. Hope that helps clear up some things for those who have been wondering. Have a great day. Jim, AB0UK K2/100 S/N 4787 I see that Elecraft offers a Heil Proset tailored to the K2. Ironically, I bought a Proset just a few months ago with the HC4 element. Can anyone tell me how superior the mic in the Elecraft Proset is to the HC4 element in the set I currently own? (I'm really hoping someone will tell me I can keep the set I have, but an objective opinion would always be preferred!) __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.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
