Hi Don, I am sorry I should have said:
The K2 with the KPA100 removed behaves normally, current does not exceed 2.5A on any band at full power (between 10-17 Watts depending on band 40M I get the most power) I have retuned 80 and 160M and I have checked all the components for correct value C11,12,13,14,15 + 16, L34 +5, 160M board checked C1,2 and 3 and L1 and L2 for 21 turns. Now UK band is 3.5 to 3.8Mhz 300 KHZ wide 80 Metre gives full power where ever I centre tune 3.6, 3.65, 3.7 or 3.75 MHz, now top band I get 15 Watts if I tune at 1.9 MHz drops off a bit at 1970 upwards, and also 1840 downwards, however, in dB terms lest than 1.5dB across the band, looks worse in watts when you see 15 drop to 10! I have compromised top band to give the max output between 1900 and 2000. It is better than it was. With your help, I am beginning to think that the input match to the KPA 100 is not 50 OHMS on top band, hence the high current warning( High return loss). I will replace the co-ax, as a start, and measure S11 and S12 form my network analyser, and check the match into the KPA100 and report back, it is odd the other bands seem happy with the match. I must of damaged something somewhere removing the KPA100. 73's Andrew > Andrew, > > FB on all of that. > Before doing anything else, remove the KPA100 and run the > base K2 into a dummy load. With the power at maximum, > note the current draw during a TUNE (press DISPLAY to see > the voltage and current). Do that on 160 as well as on > 80 and 40 (to compare the current per band). If you > receive a HI CUR message, increase the CAL CUR setting > (up to 4 amps) to see if it goes away. > > If the 160 meter power output and current draw is similar > to the other bands, then you can say the base K2 is OK > and look for a problem in the KPA100. (the current draw > at max power will normally be lower on 40 meters). The > problem can actually be in the base K2 160 meter LPF - the > above test will reveal it if present. > > 73, > Don W3FPR. > > Andrew Lenton (Linux account) wrote: > > > > Hi Don, > > > > Ah very good point this rules out the low pass filter on > > the KPA 100, as low power is OK. I only have this > problem on 160, as 80 to 10 are fine > > > Th High current only show up on 160 M, the display on > > the K2 reads the same on the external watt meter Bird > through line. SO! symptoms below are: > > > > > 1 Power on display matches Watt meter from 160 to 10 > > ( all be it 160 is 60 Watts Max) > > 2 Power from 80 to 10 max 111 Watts on display and > > meter, no high current warning > > 3, Power after 60 watts on 160 I get high current > > warning 4, I did not disturbed R 26 it was covered > > by metal plate when I removed the KPA100 to make way > > for the DSP, and the setting of R26 would also > affect other bands > > > The Bird meter was calibrated this year with all its > > elements, also I have more than one Watt meter, all > > say the same low power on 160 and high current > > > > Something must have been disturbed somewhere!! I > guess? > > > 73's > > > > Andrew > > > > > > On Sun, 2008-10-26 at 10:43 -0400, Don Wilhelm wrote: > >> Andrew, > >> > >> If the KPA100 low pass filter were a problem it would > misbehave at both >> the low and high power ranges > because it is always in the circuit with >> the KPA100 > connected. >> > >> A "Hi Cur" message means the *base K2* is drawing > current in excess of >> the CAL CUR setting, and the > power will be reduced to control the current. >> > >> If the HI CUR message only shows up when driving the > KPA100, then I >> would look for a problem in the input > of the KPA100, or mis-calibration >> of the wattmeter in > the KPA100. If you bumped the setting for R26 while >> > working on the KPA100, that in itself may be sufficient to > explain the >> HI CUR indication. Did you measure the > actual power output with an >> external wattmeter or are > you depending on the K2 display? If the >> internal > wattmeter is not properly calibrated, the actual power > output >> can be much greater than indicated by the K2. > >> > >> 73, > >> Don W3FPR > >> > >> > >> Andrew Lenton wrote: > >> > Hi Don, > >> > > >> > Thanks for that, Putting aside the K2's low power on > 160, which no doubt has >> > a component error value > somewhere, the KPA 100 has been working at 111 Watts >> > > for two years until I disturbed the PA last week to make > way for the DSP >> > board. So something has happened to > the KPA100. I only get a high current >> > warning when > the KPA100 is in use. 80 to 10 Metres is fine 11 watts no > >> > warnings! I think something has happened to the high > power low pass filter, >> > any thoughts? > >> > > >> > 73 > >> > > >> > Andrew G8UUG > >> > > >> > > >> > > > ---------------------------------------------------------- > -------------- > > > _______________________________________________ > > Elecraft mailing list > > Post to: Elecraft@mailman.qth.net > > 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 > > > ---------------------------------------------------------- > -------------- > > > > > No virus found in this incoming message. > > Checked by AVG - http://www.avg.com > > Version: 8.0.175 / Virus Database: 270.8.3/1747 - > Release Date: 10/26/2008 9:27 AM > > > _________________________________________ Check your Email accounts at http://www.MyEmail.com Login from home, work, school. 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