Oops, I sent this to Don by himself, but thought I should send it to the list just in case it helps someone.
Thanks Don, just an update. I re-nulled C55 and it nulled fine. When I checked the voltage at U4 pin 1, it was 2.8V which was a little low. Then I set R1 & R2. After doing that, the SWR into a dummy load is 1:9.9. I'll take the antenna tuner apart and look to see what I can find. Thanks & 73 Jay W9IUF On Sat, Jun 20, 2009 at 12:46 AM, Don Wilhelm<[email protected]> wrote: > Jay, > > It really sounds as though you have a problem with the wattmeter in the > KAT2. > Try balancing and calibrating the wattmeter again. If you cannot achieve a > good null with a good 50 ohm non-reactive dummy load, check T1 and its > associated components (T1 for well tinned and soldered leads and C34, R3, > R4, D1 and D2 for god soldering and proper orientation). > > If you cannot achieve a good null when balancing the wattmeter, stop and ask > for specific help. The null is a pre-requisite to proper calibration. > > 73, > Don W3FPR > > Jay Sissom wrote: >> >> Don (& list), >> >> I started doing some testing tonight and have narrowed it down. >> >> I took out the antenna tuner and tested each band at the 2W setting, >> 5W & 10W setting on the power knob. I have an external watt meter and >> dummy load attached. The power didn't match exactly on all the bands >> but it was fairly close (between 1.9W - 3.5W on 2W setting, 4.9 - 7W >> on 5W setting and 9W - >10W on the 10W setting). My Oak Hill WM2 >> meter only goes up to 10W. >> >> Then I re-installed the antenna tuner and started the test again. I >> connected to Ant 1 and had the ANT setting set to CALS. On 28060 the >> 2W setting measured 2W on the meter but gave an SWR of 1.4. At 5W it >> was SWR 1.5 and at 10W it was SWR 3. The other bands were similar. >> When I got to 21060 at 10W, the display said Hi Cur then showed an SWR >> of 3. At 10106 with 10W, it also said Hi Cur then the radio shut down >> and wouldn't come back on. I don't smell smoke or anything so I'm >> assuming the fuse reset and I'll need to wait for it to cool down. >> >> So it is definitely a problem with the antenna tuner. I think this >> has already identified a problem and I shouldn't keep going with this >> test. I'll take the antenna tuner out of the lid and look at it in >> more detail. But of course, any other ideas would be appreciated. >> >> Thanks & 73 >> Jay >> W9IUF >> >> On Fri, Jun 19, 2009 at 12:56 AM, Don Wilhelm<[email protected]> wrote: >> >>> >>> Jay, >>> >>> The real answer is "it all depends". >>> Since this is a very recent K2 serial number, it may be that this problem >>> has been present since it was built and was the reason that the original >>> builder sold it - that is an unfortunate situation, but it must be >>> considered. >>> >>> First, set your CAL CUR to 3.50 amps and try again. >>> LoP indicates that the K2 is not developing adequate power to enable >>> proper >>> tuning for the KAT2 (it needs 2 watts to tune). >>> >>> Then set the K2 ATU menu to CALP and see if it will do a TUNE into a >>> dummy >>> load - first try at 5 watts power requested, then 10 watts and finally at >>> maximum requested power. Does the HI-CUR message appear at all those >>> power >>> levels? Or only at maximum power? >>> Next, try each band separately (doing the tests as above). Does the >>> HI-CUR >>> message appear on every band? or only some bands? >>> >>> After those tests, set the ATU menu to AUTO and do a "TUNE" into the >>> dummy >>> load. You should hear some relays click and after the tuner has set its >>> L >>> and C values to match the 50 ohm load, it should exit from TUNE. >>> >>> If all that does not produce satisfactory results, there is something >>> wrong >>> with the K2. To troubleshoot it, the first step is to remove the KAT2 >>> and >>> operate the base K2 directly into a 50 ohm non-inductive dummy load. If >>> it >>> does not produce good power output without HI Cur messages, then there is >>> a >>> problem with the base K2 - likely in the Low Pass Filters or with the T4 >>> output transformer. We can help further if we have more specific >>> information - what bands fail? what bands work? How much power is really >>> produced? >>> >>> 73, >>> Don W3FPR >>> >>> Jay Sissom wrote: >>> >>>> >>>> Hello, I'm helping a friend who purchased a used K2. The K2 is a >>>> serial number 6xxx with a KAT2, KSB2 and KBT2. >>>> >>>> When tuning with the antenna tuner into a dummy load, sometimes The >>>> message "Lo P" appears on the display. It would also give the "Hi >>>> Curr" message with the current limit set to 2.5A. Does it seem right >>>> that the radio would draw that much current when tuning into a dummy >>>> load? >>>> >>>> Any info on this would be appreciated. I'm finishing up the DSP, 160m >>>> and KNB2 options for the radio but would like to get this fixed before >>>> making changes. >>>> >>>> Thanks & 73 >>>> Jay >>>> W9IUF >>>> >>>> >> >> ______________________________________________________________ >> 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 >> ------------------------------------------------------------------------ >> >> >> No virus found in this incoming message. >> Checked by AVG - www.avg.com Version: 8.5.339 / Virus Database: >> 270.12.80/2187 - Release Date: 06/19/09 06:53:00 >> >> > ______________________________________________________________ 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
