Fraser, I would also be interested in a solution to magnetic field sensitivity in my K2/100. I found that a Radio Shack Optimus speaker placed within 8 inches of my K2/100 caused distortion on both transmit and receive. I'm not technically astute enough to call this "phase noise", I just thought it was one of those undocumented features similar to beta software product releases. I have not seen the distortion problem occur when using my amps (one Ameritron AL-80B and one Dentron Clipperton L) as Earl, K6SE has, but they are both a couple of feet from the rig and are not as potent as an Alpha. Since I'm not really a QRPer, I simply bought the K2 because it has such great specs in the areas I was interested in; i.e. close in selectivity/descernability (I know everyone in the UK cringes when Americans hammer the Queens English) for contesting. In fact, I would like to build a second one to complete my SO2R (Single Op 2 Radio) contest station, but I would like to raise my comfort level with the magnetic sensitivity issue.
Lastly, as far as the phase noise limited tests shown for a K2 in some of the published comparisons, I saw a "nice" (meaning = understandable to the technically challenged such as myself) post on this reflector that described the K2's design itself as being max'ed out with the phase noise limitation, so I am not expecting anything further to be done to improve the phase noise issue. The K2 handles contest conditions MUCH better than my pair of old Icom IC-765s and that means I'll probably have to learn to live with an idiosyncrasy or two in the magnetic field department. Bob K5WA K2/100 #4687 Message: 5 Date: Sat, 19 Mar 2005 10:26:05 +0000 From: "Fraser Robertson" <[EMAIL PROTECTED]> Subject: [Elecraft] magnetic fields and phase noise? To: [EMAIL PROTECTED], [EMAIL PROTECTED], [email protected] Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; format=flowed Interesting Earl, the non exhaustive tests I've done indicate that it is not due to magnetic fields. But if indeed that is the case, there must be a relatively easy, if perhaps not elegant, way of significantly improving this. Has anyone else investigated this? 73 Fraser G4BJM >From: Earl W Cunningham <[EMAIL PROTECTED]> >Over a year ago I noticed this problem, which occurs only when my K2 is >driving my Alpha linear. After extensive testing done by me to determine >the cause of the problem, is was found to be caused by hum from the >magnetic field of the linear amplifier's HV transformer getting into the >PLL circuit of the K2. In my case, 6 feet of separation between the K2 >and the linear was not enough to eliminate the problem, however with 30 >feet of separation (with the K2 and amp in separate rooms) did solve the >problem. This answer is unacceptable, of course. Bob Evans (713) 937-9013 _______________________________________________ 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
